Fermentation of white wine with wild yeast. Three methods to stop homemade wine from fermenting

The need to stop fermentation until all the sugar has been converted into alcohol or the wine has reached its maximum strength (natural reasons for stopping) is often caused by the desire to speed up the preparation process or maintain the current characteristics of the drink (sweetness and strength). In home winemaking, three methods are used to stop fermentation, suitable for all types of wines (grape, apple, cherry, etc.):

1. Fixation with alcohol. The simplest and most effective method for long-term storage of wine. Wine yeast stops working at a strength above 14-16% (some artificially bred strains are active at an alcohol concentration of up to 18%, but these are isolated cases).

To stop fermentation, you need to remove the wine from the sediment and fix it with alcohol (preferably grape distillate) or vodka to a concentration of 16%. If the initial sugar content of the raw material is unknown, it will not be possible to calculate the natural strength obtained by fermentation. In this case, add 10-15% alcohol by volume of wine.

Disadvantages: the wine becomes very strong, the taste changes, vodka can give off an unpleasant odor.

2. Stopping fermentation with cold. The only method that does not affect the aroma, taste, sweetness and strength of wine. At temperatures below 10°C, yeast fungi go into a state of anabiosis (hibernation) and precipitate at the bottom.

To stop fermentation, you should transfer the wine to a cold room with a temperature of 2-10°C (necessarily above zero) and leave for 3-5 days until fermentation stops completely, sediment forms and the wort is at least partially clarified. Then remove the wine from the sediment and store at a temperature not exceeding 16°C.

Disadvantage: there is no guarantee that all the yeast will be filtered out with the sediment. As the temperature rises, fermentation may resume. To prevent this, add sulfuric anhydrite (3-4 grams per 10 liters) or sorbic acid (according to the instructions) to the wine. But the use of preservatives is not the best solution for home winemaking.

3. Heat treatment. Wine yeasts die at temperatures above 40°C. To stop fermentation, simply heat the wine above the yeast survival point.

In classical heat treatment, wine removed from the lees is heated to 55-70°C (pasteurized) to destroy not only yeast, but also other harmful organisms (molds, viruses, etc.) that can survive in more extreme conditions. The stronger the drink, the lower the temperature. Then the wine is pasteurized for 10-20 minutes, cooled to 10-16°C without air access (difficult to implement at home), poured into storage containers and hermetically sealed.

Disadvantages: heat treatment degrades the taste and aroma of wine. To prevent re-infection, it is necessary to protect the wine from contact with the external environment during cooling; without this, the effectiveness of pasteurization decreases.

The grape harvest was a great success and there are plenty of raw materials for making homemade wine. The wine must is prepared, but the fermentation process either does not begin at all or stops at some point. What to do when the wine stops fermenting? Most often, the situation is quite fixable, you just need to determine what the problem is.

Reason one: not enough time has passed

Yeasts are single-celled fungi that require certain conditions for full life. It takes some time for the yeast to activate and start working. You should not expect that immediately after installing the water seal, the wine must will begin to foam and gurgle. Depending on the cooking recipe, the amount of yeast, sugar, and temperature conditions, the activation period for the beginning of the fermentation process depends. It can vary from several hours to three days.

Advice! If all the conditions for the correct preparation of wine must are met, you need to wait 3-4 days, and if the fermentation process has not begun, then only then draw conclusions.

Reason two: poor sealing of the container

This problem occurs most often among novice winemakers. If the fermentation tank is poorly closed and complete sealing is not ensured, then carbon dioxide will escape into the free space. Accordingly, bubbles will not form on the surface of the wort. If a rubber glove is used as a water seal, then in case of poor sealing it simply will not inflate. Wine fermentation occurs, but it is simply not visible.

If the sealing is insufficient, air enters the fermentation tank, which contributes to the acetic souring of the wine wort. When the process is not controlled, it will be difficult to correct the situation. You can open the fermentation container no more than twice a day if necessary. For example, if you need to reduce foam or add sugar.

Advice! Carefully check the tightness of the fermentation tank. The water seal should fit tightly to the neck of the bottle. To ensure reliability, experienced winemakers seal the joints between the water seal and the container with dough or wrap it tightly with electrical tape.

Reason three: incorrect temperature conditions

This is perhaps the most common reason why wine does not ferment. Wine yeast remains active at a temperature of + 10-30 C°. In the cold they begin to fall asleep, and at very low temperatures they completely die. The optimal temperature for fermentation of wine wort is + 15-25 C°. Even minor temperature changes can affect the activity of wine yeast, for example, changes in day and night temperatures.

Advice! Check the room temperature; if it is low or too high, move the container with the wine must to a more suitable place. Make sure that the temperature remains constant without unnecessary fluctuations.

Reason four: too high or low sugar content

Advice! You can check the sugar content by taste. The wort should be sweet, but not sour or cloying. You can measure the sugar content of wine using a special device - a hydrometer. If there is not enough sugar, then it should be added; if the wort is too sweet, then it can be diluted with sour juice.

Reason five: the consistency is wrong

Sometimes the wine wort turns out to be too thick in consistency, most often this happens when working with berry raw materials: bird cherry, rowan, currant. Thick wine must does not lend itself well to mechanical filtration and, accordingly, does not ferment.

Advice! Wine wort that is too thick must be diluted with water. You can add no more than 15% of the liquid from the original volume.

Reason six: low quality yeast

Wild yeast contained on the surface of berries and fruits is characterized by its instability. They can cease to operate at any time, even under favorable conditions.

Advice! To activate fermentation, you can add crushed grapes or raisins to the wine must; you can also use wine yeast.

Reason seven: mold

This problem can occur when using rotten or moldy wine materials. Also, the cause of mold may be a poorly washed fermentation tank. Fungi spread very quickly in wine must.

Advice! If mold is found, then the top film must be removed and the wort strained into another fermentation container. However, there are no guarantees that this measure will help. Getting rid of mold is quite difficult. If the wine is affected by mold and even changing the container did not help, then the wine must should be poured out and mistakes of this kind should not be repeated in the future.

Reason eight: the end of the fermentation process

Wine yeast stops working when the alcohol concentration reaches 10-14%. It is impossible to obtain wine of greater strength using natural fermentation. To increase the degree, alcohol is added to the drink. It should be borne in mind that after adding alcohol, the fermentation process of wine stops instantly, so it should only be added to ready-fermented wine.

Advice! Homemade wine ferments for about two weeks. The end of the fermentation process is indicated by sediment in the form of settled pulp at the bottom, cleared liquid and the cessation of seething.

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Grape wine is an ancient drink, created by centuries of labor and skill of peoples inhabiting vast areas of temperate and hot climates. From the simplest home processing of wild and “domesticated” grapes, wine production has come a long way of development and improvement. Many wines with established high quality and established names are known in the world wine trade and occupy a large place in the exports of wine-producing countries. Along with this, a colossal amount of wine is produced for home use and for sale within its grape-wine-growing region.

FERMENTATION

It is enough to crush the grapes in a vessel for spontaneous heating of the resulting mass to occur, leading to the gradual disappearance of the sweet taste. This process is called alcoholic fermentation (alcoholic fermentation), thanks to which grape juice actually turns into wine.

A microscopic fungus of the species Saccharomyces cerevisiae - yeast - develops in the wort. As a rule, the yeast that is present on the skin of the berries is sufficient for fermentation, but recently other, specially grown cultures are increasingly used. Unfortunately, their use often results in the aromas of different wines becoming surprisingly similar.

Feeding on sugar, yeast converts it into ethyl alcohol and carbon dioxide. By-products of their vital activity also include glycerin, acids, higher alcohols and esters, which even in small concentrations take part in the formation of the aroma of the future wine. Alcoholic fermentation occurs with the release of thermal energy. Therefore, the vats become hot, making temperature control absolutely necessary. Sometimes it is necessary to apply cooling so that the temperature of the must does not go beyond certain limits (20° C for white wines, 25-30° C for red wines), otherwise this may adversely affect the quality of the wine. In some cases, in addition to alcoholic fermentation, malolactic fermentation is also used after it. This process was introduced to improve the quality of red wines only in the 60s. In relation to white wines, its benefits are not so obvious.

It is produced by lactic acid bacteria, the same ones that cause milk to sour. They decompose malic acid into lactic acid and carbon dioxide, at the same time “grabbing” other organic compounds. If such a process occurs spontaneously and is not planned by the winemaker, then it can lead to damage to the wine material. There are preparations from cultural strains of lactic acid bacteria. They are used to improve the taste of high-acid wines. But to begin such a biological acid reduction, you first need to partially deoxidize the wort with chalk, then add this drug, raise the temperature to +20 C and stop the process in time by sulfitation. For processing high-acid wort, special acid-reducing yeast called acidodevoratus, which in Latin means “acid absorbers,” is better suited. During normal alcoholic fermentation, they by-product convert malic acid into alcohol and carbon dioxide. As a result of acid reduction, the wine becomes softer, subtler and acquires a complex aroma. At the same time, the biological stability of wine increases, which is very important for its subsequent storage.

Therefore this type of fermentation is called apple-ethanol . It is used to make dry wines from raw materials with excess acidity.

In many cases, when producing wine, the chaptalization method is used, named after the French chemist Jean-Antoine Chaptal (1756-1832), who served as French Minister of Agriculture under Napoleon I. This method involves adding sugar (grape, beet or cane) in order to increase the alcoholic strength of wine. In France, its use is permitted subject to a number of preconditions. The added sugar must provide an alcohol content by volume of 2.5-3.5% in Champagne, Alsace, Jura, Savoy and the Loire Valley and no more than 2% in other French appellation d'origine vineyards.

When producing dry wines, sugar must ferment completely. In the production of semi-sweet and semi-dry - partially. The situation becomes a little more complicated in the production of fortified (with the addition of alcohol) and dessert (special technology) wines. Here it is impossible to achieve high alcohol (14-17%) through natural fermentation. At 17% alcohol, the wort self-preserves and the yeast dies. Moreover, the wine should contain 14-17% sugar. Therefore, fermentation is carried out until the required sugar remains in the wort, and then alcohol is added, bringing its content in the wine material to the required level. That is, fermentation is interrupted by alcoholization. According to the correct technology for fortified wines, natural alcohol should be at least 3% out of 14%.

It is important that the wort is protected from exposure to air (usually a layer of carbon dioxide acts as a protective screen), otherwise you will end up with vinegar instead of wine. At the same time, air is necessary to maintain the vital activity of yeast, so the wort is ventilated from time to time.

Some important information about alcoholic fermentation.

At temperatures below +10 C, fermentation stops. At temperatures from +10 C to +27 C, the fermentation rate increases in direct proportion, that is, the warmer it is, the faster. From 1 gram of sugar during fermentation the following is formed: - ethyl alcohol 0.6 ml. or 0.51 g - carbon dioxide 247 cm3 or 0.49 g. - heat dissipated into the atmosphere 0.14 kcal Sugars are actively absorbed by yeast, with the sugar content in the wort ranging from 3% to 20%. As soon as the alcohol concentration in the wort reaches 18%, all wine yeasts die. There are some types of cultivated yeast that die even at an alcohol content of 14%. These are used to produce wines with residual sugar. The carbon dioxide released by the yeast cells in the wort slows down their work. The gas bubble, while it is small, “sticks” to the wall of the yeast cell and prevents the flow of nutrients to it. This situation continues until the cell “inflates” this same bubble to a certain size. Then the bubble floats up and carries the yeast cell with it upward to the surface of the fermenting liquid. There it bursts, and the cell sinks to the bottom of the fermentation tank. This process is conventionally called "boiling", and is considered a waste of time in the process.

Types of yeast.

Fermentation can be carried out on wild yeast, which live naturally on a grape bush, or on cultural yeast, bred and selected by humans in laboratory conditions. The choice of yeast depends on the will of the winemaker. Wild yeast and its spontaneous fermentation- live on grape berries and grape bushes. When grapes are processed into wine, other microflora enters the must along with them. On average, freshly squeezed grape juice contains mold fungi in a proportion of 75 to 90%, and various types of wine yeast 10-20%. Some microorganisms die in the wort already at the first stage due to the high acidity of the juice and sugar content. Some try to compete with wine yeast and begin to multiply, but soon they too die, as the reserves of dissolved oxygen in the wort run out. By this time, wine yeast reaches a high concentration (about 2 million cells per cubic cm of wort) and switches to an anaerobic type of sugar processing. And thus, they get the entire volume of the wort at their disposal. Next, different types of alcoholic wine yeast begin to compete with each other. The main limiting indicator is how much alcohol is in the wort. While it is small, the largest numbers develop in red juice of Hanseniaspora apiculata (apiculata or acuminate), in the juice of white grapes - Torulopsis bacillaris. After accumulation of about 4% alcohol, both species die off. From the “carcasses” of dead yeast, nitrogenous substances begin to flow into the wort. After which it becomes possible to actively reproduce yeasts of the genus Saccharomyces, mainly the species ellipsoideus, in Russian - ellipsoidal yeast. They carry out both main fermentation and secondary fermentation. The last thing, which is interesting, occurs, again, after the appearance of nitrogenous substances from dead cells in the wort. When 16% alcohol accumulates, ellipsoidal yeast dies. The final fermentation is carried out by alcohol-resistant yeast oviformis (egg-shaped). But they also fall out at 18% alcohol. Now the wine material is practically sterile. Only oxygen in the air can spoil it. Fermentation with wild yeast can produce high-quality wines with a huge range of flavors and aroma. After all, several types of yeast take part in their creation, replacing each other. But there is a significant risk of getting low-alcohol or low-alcohol wine if at some stage the relay of yeast fungi is interrupted. Cultured yeast and pure culture fermentation- cultural yeast is obtained as the offspring of one yeast progenitor cell in the conditions of the microbiological industry. Therefore, the wort is populated with only one type of yeast with absolutely identical properties. There should not be any other microorganisms in it. In this case, we can select exactly those yeasts that will give us a product of the desired properties, for example, sherry yeast, champagne yeast, yeast for red wines, sulfite-resistant races, races with a high alcohol yield, heat-resistant, cold-resistant, acid-tolerant, etc. Competition between microflora will be excluded, and the product will most likely be exactly what the winemaker was counting on. It should be noted that after numerous experiments, the modern wine industry has come to the conclusion that the use of pure yeast cultures can be limited if the raw materials have some drawbacks or it is not possible to maintain the correct temperature conditions during the fermentation process.

Fermentation speed.

The best fermentation is slow fermentation. At high temperatures, yeast so actively processes the sugars of the grape must that the seething bubbles of the resulting carbon dioxide carry aromatic, flavoring substances and even alcohol vapor into the atmosphere. The wine turns out flat, with unexpressed taste qualities, and loses its degree. At temperatures from +25 to +30, excessively vigorous fermentation occurs. Yeast multiplies quickly and quickly dies; nitrogenous substances are constantly entering the wine material, which are formed during the decomposition of dead cells, and this increases the risk of cloudiness, disease, and overoxidation. At temperatures above +30 C, the yeast dies, and sugar (poor quality) remains in the wort. In such a nutrient medium, foreign bacteria immediately begin to multiply and the product spoils.

Fermentation stages.

The entire fermentation period is conventionally divided into three phases: fermentation, vigorous fermentation, and quiet fermentation. Fermentation- the initial period when the yeast adapts to the conditions in the fermentation tank and begins to reproduce; Violent fermentation- the period when the yeast has multiplied, occupied the entire volume of the wort and switched to an anaerobic method of nutrition with the release of alcohol and other substances into the surrounding liquid, their numbers are growing; Quiet fermentation- basic sugar is converted into alcohol, the number of yeast cells decreases. This diagram shows stationary fermentation method. It is important here that the container is filled with fermenting wort no more than 2/3 of the volume. Otherwise, with foam in the middle phase, the contents will be thrown out. This leads to irrational use of fermentation tanks and instability of processes inside it. Fermentation proceeds more stably when top-up fermentation method. True, this technology can only be used for the production of dry wines. It is carried out as follows: 1. first, the container is filled with 30% of the total volume with wort and the yeast mixture is added to it in full; After 2 days, fermentation will enter the vigorous stage, and the wort will warm up. 2. on the third day, another 30% of the prepared fresh wort is added; 3. After another 4 days, another 30% of fresh wort is poured into the container. The fermentation tank is thus filled almost to the top, and the fermentation process itself occurs without sharp peaks and jerks in the number of yeast and their metabolic products. And this is good for the quality of future wine.

Fermentation “over four” is superquater.

Proposed by French winemaker Semichon. The main feature is that alcohol is added to the wort or pulp, before fermentation begins, in an amount of 5 percent by volume. This amount of alcohol is enough for all unwanted microflora in the wort to die. The Saccharomyces yeasts needed for fermentation do not suffer at all, but continue their work in the “cleared field.” But adding alcohol to wort is prohibited by law in most wine-producing countries. Winemakers go around and modify the supercarte method: first, using the supercard method, they obtain dry wine material with an alcohol content of about 10%, then add it to the bulk of the must in the proportion required for this method.

Fermentation on pulp.

Used in the production of red wines and some fortified white, highly extractive (rich) wines. Here, during fermentation, the task is to obtain not only alcohol, but also to remove coloring, aromatic tannins and other substances from the skins and seeds. Fermentation of pulp is always difficult. After all, it is a heterogeneous, hard and viscous mass. In addition, in order to release the necessary substances from the skin and seeds, a temperature is required not lower than +28, and preferably +30 C. But at +36 C, the yeast loses activity, and at +39 C they die. That is, for fermentation on the pulp there remains a narrow temperature range from +28 to +32 C. Fermentation on pulp with a floating cap. Carried out in vats or open containers . The wort is sulfated according to the calculation. Fill the container with it and add the yeast mixture. Stir. After some time, vigorous fermentation begins. The released carbon dioxide carries with it all the particles (flakes of pulp, skin, pieces of ridges and stalks) to the surface and keeps them afloat there. The pulp is stratified into liquid and a “cap” of solid fraction, floating on the surface, and most often protruding above it. To avoid acetic acid souring and improve the extraction of dyes, it is necessary to stir the contents of the container 5-8 times a day for 5 days. As soon as the wort acquires a rich color, it is drained, the pulp is pressed and both liquids are combined and kept until the end of fermentation. This method produces the most beautifully colored and rich-tasting wines. Fermentation on pulp with submerged cap- in order to reduce the number of stirrings when using the “floating head” method, they came up with a simplified “submerged head” method. The “cap” is sunk to a depth of about 30 cm using a grate. The number of stirrings with the cap immersed may be less, but the color of the wine will accordingly be worse. Both types fermentation on pulp can also be carried out in closed containers. In this case, a layer of carbon dioxide is formed above the cap, which to some extent resists acetic acid souring and simplifies the process.

WINEMAKING

With the completion of fermentation, human intervention in the wine making process does not stop. It requires many more operations and vigilant care until the moment when it is bottled and sent for sale. Transparency of clothing can be achieved by storing wine for a long time in a small container, for example, in a barrel, and periodically decanting it (using gravity or using a pump) in order to promptly remove settling particles. During this process, the wine not only gets rid of particles suspended in it, but is also ventilated, enriched with oxygen. In Bordeaux, for example, it is customary to rack red wines 4 times during the first year of aging and another 2-3 times during the second.

The wine is also decanted after fining. It was first introduced into winemaking practice in the 18th century. This process got its name because initially it used glue extracted from the swim bladders of fish, mainly sturgeon and catfish. Currently, it is used not only for clarification, but also to stabilize wine. This method consists of adding organic (fish glue, egg white, gelatin, casein) or inorganic (yellow blood salt) compounds to the wine, which, coagulating, envelop not only suspended particles, but also some other components of the wine, which can subsequently lead to deterioration of its quality. Thus, fining of red wines is necessary to eliminate excess coloring matter, which otherwise precipitates. In cases where coagulation of natural proteins is undesirable, as, for example, when fining white wines, they are deposited on materials that do not interact with wine substances - silica, kieselguhr, bentonite, kaolin, asbestos.

The use of modern filters makes it possible to separate particles of a given size from wine; they can be not only particles of the skin or pulp of berries, but also, for example, yeast cells. During centrifugation, the wine is rotated at high speed in a special drum, so that the impurities it contains are thrown onto the walls and then removed. However, in France there are many winemakers who claim that fining, centrifugation and filtration deprive wines of some of their aromas, and red wines also deprive them of tannins.

However, to achieve transparency in wine, it is necessary to ensure its subsequent stability. Since living cells (particles of berries, yeast, bacteria) take part in the wine production process, its composition is extremely complex. Its various components can enter into chemical reactions with each other. The consequence of processes of this kind are the so-called cash registers - cloudiness of the wine and sedimentation. Currently, methods are known to prevent troubles of this kind. To prevent the development of microorganisms, it is necessary, in addition to maintaining cleanliness, to fill the containers to the top, and then top them up so that the wine does not come into contact with air oxygen. The use of an antiseptic such as sulfur dioxide (SO2) also gives good results. It is used at various stages of wine production (disinfection of containers, prevention of malolactic fermentation, etc.) in solid, liquid and gaseous forms. However, an excess of this substance not only negatively affects the taste of wine, but can also cause poor health. Some winemakers pasteurize their products by heating them for a short time to 85° C. This kills the yeast and bacteria contained in the wine, but at the same time deprives it of its ability to age: it stops evolving once bottled.

In some cases, during production, products from many vineyards, harvests from different years or obtained from different grape varieties are combined. This operation can be carried out already when opening the grapes, but more often this is done after stabilizing the wine or during its aging. In France, there are usually two types of it:

assembly - a combination of different grape varieties and/or products from different vineyards of the same harvest year and within the same appellation. Assembling is a common procedure in the production of high-quality wines. It allows you to improve quality, while emphasizing the characteristics of the type and style of each of them;

Blending (coupage) is a combination of wines from different regions and/or harvests from different years. Some improvement in quality is achieved by averaging the wine and losing its individuality. Blending is applied only to sparkling (including champagne), table and local wines.

Before bottling, the wine can be aged in wooden barrels. However, aging continues in bottles.

BOTTLE AGING

After the production of wine is completed, it is bottled, with or without subsequent pasteurization. The bottles are placed so that the cork is in the wine.

A minimum volume of air is left in the bottle, since the less air volume, the less oxidation occurs. To ensure that wines are stored properly, they are placed in vinnitsa - special warehouses (cellars). The cellar for storing wine must be dry, away from anything that can mold, rot, or deteriorate, since all this affects the taste and aroma of wines, even bottled and sealed.

On the eve of bottling, the bottles are thoroughly washed and turned upside down.

Immediately after pouring the wine into a bottle, the cork is lowered into alcohol or cognac with the end that goes into the neck of the bottle, which is why the cork goes into the neck better. The plug is inserted with a special machine. The outside of the neck is covered with special resin and sealing wax and, to ensure further storage of wines, the bottles are placed on their sides so that the cork is in the wine.

BARRICK

It is based on the exchange of substances between wine and the oak wood of the barrels in which the wine is cultivated. During aging, the wood releases valuable aromas and tannins into the wine. In addition to the traditional astringency that wine acquires thanks to oak tannins, white wines usually also have a vanilla-peach aroma. Red wines - cherry. Some champagne wines are also produced in oak barrels (Bollinger, Roederer, Krug varieties). Oak barrels are not suitable for all types of wine. If they correspond to and complement such strong varieties as cabernet sauvignon or chardonnay, then they overwhelm such a fine wine as riesling.

After the first filling, the wood gives up most of its substances, so good winemakers replace the barrels after two or three cycles. There are exceptions: The wine house of Louis Roederer pours high-grade wines into large barrels (French foudres) with a volume of 4,000-5,000 liters, where they mature and are stored for up to 60 years. The Krug wine house produces typical wine using barrique technology in slightly smaller standard 205-liter barrels, traditionally used for champagne.

Some winemakers, instead of the classical technology, pour young wine into metal containers and then “bring” it to barrique consistency using the method of additional artificial “tanning”, adding oak chips - “chips” - to the wine. The wine-soaked chips sink to the bottom of the container and release their aroma there. However, steel barrels, unlike wooden ones, do not “breathe”, and therefore the proper bouquet (a mixture of wine and woody aroma) is to some extent not obtained. Many winemakers, gourmets and professional tasters do not recognize this winemaking technology.

Wines prepared in barrique barrels have associations of lovers, chains of specialty stores and a trademark all over the world.

Until October 2006, the technology of wine with the addition of chips was prohibited in the European Union. After the conclusion of inter-European trade agreements on wine in October 2006, the ban was lifted. However, artificial flavoring additives remain prohibited. Technology using “chips” is not subject to mandatory declaration. However, the producer of such wine does not have the right to indicate on the bottle label that the wine is “produced in an oak barrel” or “matured in an oak barrel” or “kept in an oak barrel

Duration of wine aging

The development of bottled wine is often compared to the life cycle of a person: it gradually matures, reaches maturity, and then inevitably begins to age and eventually die. At the same time, most of its components precipitate, and it itself becomes lean and sour. The stages of maturation and aging last for a long time and include barrel and bottle aging of wines. The opinions of winemakers about the life expectancy of wine and the optimal aging periods, subject to the storage conditions of wines, are contradictory. Which is quite natural, since grapes come in different varieties and qualities for winemaking, the process of preparing wine occurs differently.

But wine reaches its highest qualities by 12-16 years, and after 20 years it begins to fade and by 45 it degrades. Table wines have the best life span of 10-20 years, and after 25 they begin to deteriorate. At the same time, strong wines (Madeira, Tokaj) develop up to 50-60 years. Sherry lives for over 160 years.

During aging, wine undergoes complex and varied changes, not all of the reasons for which are known to modern science. It is clear, however, that oxidation plays an important role among them: air is contained in dissolved form even in wine placed in a hermetically sealed vessel. The most obvious of the changes concerns the color of clothing. They are especially striking in red wines: the characteristic bright red color of young wines acquires yellow shades as they age, approaching the color of brick or tile. When describing the appearance of red wines after several years of aging, tasters often call them brick or tile red. In very old wines, the red tint completely disappears, and yellow and brown become the predominant colors. White wines, on the other hand, darken. It is interesting that very old wines - both white and red - have approximately the same color. During aging, the aromas of the wine develop: the so-called primary aromas, which it owes to the grapes, and the secondary ones acquired during aging (they are dominated by fruit and floral tones) are replaced by tertiary ones (mainly animal ones). A bouquet appears, the presence of which is a distinctive property of old wine. The aggressiveness of the wine is smoothed out, its tannins become less harsh. The wine becomes more rounded, velvety, soft.

The question of the maximum “life” can only be raised in relation to a specific wine. Some wines are best drunk within six months, while others “live” for decades. Light wines with low alcohol content do not store as well as well-structured, full-bodied and strong wines. It is not surprising that naturally sweet and “yellow” wines can age longer than others. As for the duration of storage of dry wines, it is determined by a number of factors, among which we can particularly highlight:

Types of grapes from which the wine is made

Age of vines Older, less productive vines tend to produce more concentrated wine.

Soils on which grapes are grown It is known that good wine cannot be obtained on fertile soils. On the contrary, on nutrient-poor, well-drained soils, the vines “suffer” and, subject to limited yields, produce rich, well-stored wines;

Weather conditions during the growing season are what is commonly referred to as the millesime. Too cold a summer and lack of sunlight will not allow the grapes to reach the required ripeness, and rain during harvest will make the wine watery. In both cases, the wine will not be suitable for long-term aging. If the shelf life of wine produced in a bad year is taken as 1, then the corresponding figure for the middle and great millesims will be approximately 2 and 4;

Features of the vinification process and working with wine For example, refusal to separate the ridges, long-term infusion of the wort on pulp, and fermentation in oak barrels increase the tannin of the wine, and therefore its longevity;

Storage temperature As it increases, the exposure time decreases;

Capacity of the vessel in which wine is stored The smaller the volume of the bottle, the more actively all reactions occur in it and, consequently, the wine ages.

In order for the fermentation process to begin as soon as possible and not be delayed, it is important for winemakers to maintain the correct temperature conditions. The main condition in this matter is the fermentation temperature of the wine: if it is too low, the yeast will not be able to activate and the wort will not ferment. We will find out what the temperature regime should be at all stages of the production of wine drinks, including maturation and pasteurization.

Wine fermentation at home: temperature

The correct temperature for fermenting homemade wine is the main criterion in winemaking. If the yeast does not have enough heat, it is unable to live and reproduce, and the wort stops fermenting. If the temperature, on the contrary, is too high, it has a detrimental effect on the yeast fungus.

At what temperature should wine ferment? The optimal fermentation temperature for wine is 16-20 degrees, especially in the first week. Therefore, the wort must be kept in a room where there are no sudden temperature changes, otherwise the fermentation process will slow down or stop altogether.

Knowing at what temperature homemade wine should ferment, we make sure that the place where the wort will stand is protected from the sun's rays (to avoid overheating) and drafts (to avoid hypothermia).

Fermentation of wort in the cold season

If you decide to make wine in the cold season, the main thing is to consider the temperature at which the wine ferments. To ensure it ferments well, do the following:

1. We place the wort in a heated room, enclosing the container with wooden shields.
2. We heat the wort to start the fermentation process: pour a third or half of the wort in a separate enamel or glass container and heat it up. Then pour it into a container with the rest of the raw materials.

Having mixed the contents of the bottle or jar well, we get a warm wort, ready for fermentation, which will soon start.

Now you know at what temperature homemade wine ferments.

Wine maturation temperature

When the wort has fermented, the wine is filtered, poured into other containers and covered with polyethylene lids or pierced rubber gloves. They are placed in a dark room with a temperature of 12-14 degrees Celsius.

At the same time, you need to strain the wine every week so that the taste does not deteriorate due to sediment. Wine maturation ends when bubbles stop forming in the drink. Then it is bottled and sent for storage in a room with a temperature of 6-8 degrees Celsius.

Wine pasteurization temperature

What to do if the finished wine begins to mold, sour or ferment? It needs to be pasteurized - heated without air to the desired temperature. Let's find out how this is done and what is the optimal temperature for pasteurizing wine drinks.

How to pasteurize wine

Pour boiling water over the containers where the wine will be pasteurized and turn over to drain completely.

Fill the jar with water and immerse a wine thermometer in it to adjust the pasteurization temperature, which should be:

1. For semi-sweet wines - 60°C
2. For weak table foods - 55°C
3. For sweet dessert wines - 65°C.

Pour the wine, without disturbing the sediment, into the prepared containers through a thin tube so that it has less contact with air, and close them.

When pouring, leave a space of 4 centimeters to the height of the lid, because As the wine heats up, it will expand.

• Place a terry towel on the bottom of a large, tall pan, folding it in 4 layers so that the glass containers do not burst.
• Place a jar with a thermometer and water in the center of the pan and surround it with bottles filled with wine. Add cold water to the pan to the wine level. Heat it over medium heat to the required temperature.
• Maintaining this temperature, we pasteurize half-liter bottles for 15 minutes, 0.7 liters for 20 minutes, 1 liter for 25 minutes.

Remove the pan from the heat and cool the bottles of wine to 35 degrees right in it. Then we take it out and wipe it, and when it has cooled to room temperature, we take it to the cellar for subsequent storage.

To measure the temperature of wine or mash in bottles or jars, you will need a special thermometer.

Wine thermometers are as follows:

• Bracelet thermometer. By putting it on the bottle, we find out within a couple of minutes what the current temperature of the wine is. The temperature sensor built into the bracelet, touching the surface of the container, quickly determines the temperature of the drink.
• Glass thermometer for mash. It allows you to measure the temperature of the mash at the fermentation stage of the wine. We lower it into the mash and wait a minute.
• Glass float thermometer. We immerse it in a bottle of mash, wait 30 seconds and find out the result.
• Thermometer - sticker. We glue this flexible device to the wall of a container with wine or mash, and soon we receive data on the temperature of the liquid.

With these devices you can easily determine the temperature of the must or finished wine.

Now you know what the temperature of wine fermentation, maturation and pasteurization should be. All that remains is to purchase a high-quality thermometer to measure the temperature of wine and test the basics of winemaking in practice.

People involved in home winemaking sometimes encounter this problem when the fermentation of the wine must suddenly stops. In this case, it is quite difficult to determine why fermentation stopped, because such an incident can happen even if all the technology for preparing homemade wine is followed. And this problem is quite serious, because it can lead to damage to the entire wine material, which means that the winemaker’s work will go down the drain and the products can be thrown away.

To decide what to do in such a situation, you first need to find out why the wine stopped fermenting in a particular case. What factors can cause the fermentation of homemade wine to stop, and how this process can be resumed - there will be an article about this.

Features of the fermentation process

The technology for preparing homemade wine can be different, and various products can be used in winemaking: fruits, berries, grapes. But in any case, homemade wine must undergo a fermentation process, otherwise the juice of fruits and berries will not turn into a wine drink.

Wine or yeast fungi are responsible for the fermentation of fruit juice. Typically, such fungi are found on the peel of fruits and berries, and appear as a whitish or grayish coating.

These fungi feed on sugar; in the process of their life, they process sugar, turning it into alcohol - this makes the juice an alcoholic drink. In addition to alcohol, carbon dioxide is produced during the fermentation process, which is what inflates the gloves on bottles of wine or comes out in the form of air bubbles from under the water seal.

Natural sugars are found in almost all fruits or berries; only their quantity can vary. Those products that are suitable for winemaking are those that have a fairly high content of natural sugar in the form of glucose, sucrose and fructose.

The sugar content of fruits and berries may depend on factors such as:

• crop variety;
• ripeness of fruits or grapes;
• fruit picking time;
• the aging time of fruits in the interval between harvesting and laying wine.

To prepare high-quality homemade wine, it is recommended to collect only fully ripened fruits and berries, to do this within the prescribed time frame, to prefer varieties that are characterized by high sugar content of the fruit (the taste of the fruit should be more sweet than sour).

The insufficient natural sugar content of products forces winemakers to use additional granulated sugar. The difficulty is that it is very difficult to calculate the appropriate amount of sugar, so it is better to immediately take in moderation sweet fruits and berries for homemade wine.

Why doesn't homemade wine ferment?

Not only beginners, but also experienced winemakers may encounter the problem of stopping the fermentation of homemade wine. Moreover, the wine may not initially ferment, or it may suddenly stop fermenting. There may be several reasons for this, all of them require a special solution.

Why homemade wine may stop fermenting:

1. Too little time has passed. Wine fungi need time to begin their work. The rate of yeast activation depends on several factors, including: the sugar content of the wine, the type of raw material, the temperature of the must, the type of starter or the type of fungus. In some cases, the wine may begin to ferment a couple of hours after the bottle has been sealed with a water seal. And it also happens that fermentation begins only after three days. Both of these situations are the norm, but the winemaker should start to worry when the wine does not ferment for more than three to four days from the moment the wort is fermented.

What to do to make wine ferment

Having found out why the wort stopped (or did not begin) to ferment, you can try to correct this situation. Methods to solve the problem depend on the cause.

So, you can make wine ferment in the following ways:

• strengthen the tightness of the lid or water seal. To do this, you can use batter or other adhesive mass, which you can use to coat the neck of the bottle at the point of contact with the lid or glove. Open the bottle less often, and if you do, do so only for a few minutes.
• Provide the wine with a constant suitable temperature - from 16 to 27 degrees. If the wort is overheated, you can try adding a little special wine yeast to it - fermentation should start again.
• If the wine has not started fermenting within four days and it looks too thick, you can try thinning the must by adding a portion of sour juice or water. Liquid should make up no more than 15% of the total volume.

This can be done in several ways: add alcohol to the wort, take the bottle into a room with a temperature below 10 degrees, heat the wine to 35-55 degrees (this process is called pasteurization). In all these cases, the fungi die and fermentation stops.

If homemade wine has stopped fermenting, this is not a reason to throw it away - the situation can be corrected. First of all, the winemaker must find out why this happened, where he violated the technology, and then take appropriate measures.

There are also cases when it is impossible to help the wine. Then all that remains is to learn from your own mistakes in order to prevent them from happening in the future.

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How to speed up the fermentation process of homemade wine

Making your own alcoholic beverages has always had its pitfalls, especially if the winemaker is a beginner.

Question: “How to enhance the fermentation of homemade wine?” worries many lovers who want to speed up the process of preparing it or resume it for some reason. There are several ways and methods by which you can influence the rate of fermentation of alcoholic beverages.

What affects the fermentation of homemade wine

The speed of fermentation is influenced by many factors. Not only proper care of the wort is very important so that fermentation does not stop at the wrong moment, but also the preparation of materials for it, as well as the environment.

Let us list in more detail what affects fermentation:

• ambient temperature;
• amount of oxygen;
• wine material filtration;
• containers for making alcoholic beverages;
• normal level of sugar content and alcohol content;
• unsatisfactory conditions (mold, wort souring).

How to speed up the fermentation process of wine

If you need to know how to speed up the fermentation of homemade wine, then you need to understand the fermentation process itself. Acceleration is possible by using natural and natural substances, or by using certain chemicals. Let's take a closer look.

How to enhance the fermentation process with yeast

Sometimes it happens that the fermentation of the wort occurs at a low rate. What to add to wine material for fermentation of wine? One of the reasons for this behavior of the wort may be a lack of yeast or its death for some reason.

You can add a handful of unwashed raisins or crushed fresh grapes to the wine material. Most often, winemakers use special wine yeast, adding it according to the instructions.

Acceleration of fermentation by normalizing acidity

How to improve the fermentation of homemade wine using a pH meter? The optimal value should vary between 3.5-4 pH. Fermentation may decrease if the reading is below 3.5.

To increase it, you should acidify the wine with tartaric acid (purchase in a store or add the juice of one or two lemons to three to four liters of wine).

If the indicator is above 4, then the quality of the drink may be affected by foreign harmful microorganisms. To reduce acidity and level out fermentation, you should dilute the wort with clean water (preferably spring water).

Temperature and rapid fermentation

There is an optimal temperature range for fermentation, below and above which the yeast stops working.

If you increase this indicator, the fermentation will go faster, but already at 25-30 degrees the future alcoholic drink is at risk of “catch” various diseases, because this is the most favorable environment for the development of butyric, lactic and other acids.

It should be noted that by increasing the temperature to 27 degrees, fermentation can accelerate, but once this threshold is reached and after it is exceeded, it decreases significantly. Therefore, accelerating the process of yeast propagation using temperature fluctuations should be done very carefully.

Oxygen and increased fermentation

To enhance the fermentation of wine, dosed exposure to air on the wort is necessary. You should open the wine for about fifteen minutes once a day to ventilate it. This action significantly revitalizes the work of yeast, as well as its ability to reproduce.

If the wine is slow to ferment, or the fermentation process itself begins to slow down, then in the second half of the main fermentation, air can be blown into the wort using a bellows, or simply pour the entire volume of fermenting wine into a clean container and leave for four hours.

It should be noted that at the time the wort is enriched with oxygen, it should already contain 7-8% alcohol.

Accelerating fermentation using chemicals

You can speed up the process of yeast propagation by other means, for example, by combining the wort with chemical rather than natural substances. Let's take a closer look.

It is very popular to treat barrels or other fermentation containers with special sulfur wicks. Before the procedure, the containers are thoroughly washed and dried. Then the wicks are burned in them and then filled with juice for fermentation.

One wick produces about 5-8 g of sulfuric acid, but half evaporates during filling of the bottles. It should be noted that the maximum quality of raw materials for the future alcoholic drink reduces the amount of chemical substance used.

Ammonia for wine fermentation

It is believed that yeast in wort will multiply normally not only in the presence of sugar. Many winemakers add nitrogen-containing substances to accelerate the fermentation of wine. If during fermentation there is a lack of these substances, then the wine may turn out weak, it has a high percentage of turbidity and it will not clarify well in the future.

To prevent this from happening, nitrogenous nutrition is added to the wort, i.e. ammonium chloride or aqueous ammonia solution. Simply put, ammonia.

Other fermentation activators

Among the above methods of accelerating fermentation, you can use other substances that are allowed for use:

• vitamins (thiamine, biotin, pyridoxine, etc.);
• intermediate fermentation products (acetaldehyde, pyruvic acid);
• sterols;
• fatty acid;
• yeast extracts.

It should be noted that increasing the fermentation of homemade wine does not always have a positive effect on the drink. Sometimes it is better to withstand the required number of fermentation days (this is naturally longer) than to drink tasteless wine or throw it away altogether. This is especially important for inexperienced winemakers who have just started trying to make their own alcoholic beverages, even according to proven recipes.

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Why did the wine stop fermenting or not start fermenting at all?

Even if the recipe is strictly followed, situations are possible when the wine does not ferment at all, begins to ferment ahead of time, or the fermentation process stops after a few days. Let's consider the reasons why homemade wine made from jam, grapes, berries does not play and what can be done in each of these situations.

Fermentation: what the process depends on

Fermentation is the process of decomposition of sugar contained in grape or berry must into alcohol and carbon dioxide. The main actors are yeast fungi. It is their activity that determines how long the wine ferments, how fast the fermentation process of the wine material will be, and to what extent the quality of the finished drink will be.

In the history of home winemaking, there are examples when the winemaker placed the container in a more or less suitable place, then happily forgot about it, and after 2-3 months received a passable drink. However, this is either experience or luck. In most cases, it is necessary to intervene in the fermentation process and control its quality.

For any homemade wine, there are two, sometimes three stages (the last two do not have clear boundaries) of fermentation:

• initial stage - it is at this stage that the fungi “sit quietly”, getting used to the new environment and often causing anxiety in the novice winemaker;
• active - the yeast multiplies rapidly, the beginning of this period is marked by the active production of carbon dioxide, the mass hisses, bubbles, and a sediment forms;
• quiet - fermentation continues, but in deep layers. There are few bubbles.

The second stage can be of varying duration, it depends on what strength of the future drink is desired. Active fermentation can be greatly delayed to end up with a stronger homemade wine. Bubbles are very actively visible for the first 2–3 days.

The next phase - quiet fermentation - lasts as long as the fungi have enough food, they will multiply until they have absorbed all the sugar, breaking it down into alcohol and carbon dioxide. In the recipe, the fermentation process is as follows

• Prepared raw materials for wine (wort, pulp) are poured into containers, covered with gauze, and placed in a warm, dark place;
• As soon as the first gas bubbles appear (fermentation has entered the active phase), a water seal is put on the container (most often, covered with a glove). This stage has different durations, for example, fermentation of homemade wine from apple juice and rowan (temperature 18–28 °C) will take 25–40 days. The end of the stage is determined by the fall of the glove. The new wine is ready;
• Maturation. This is a quiet period. You can add sugar to wine. Or alcohol, which will stop the fermentation process. The deadlines are also different. For the same apple-rowan wine, this means 2–3 months in a darkened room at a cooler temperature of 10–16 °C.

Interesting: winemakers have different opinions about the youth of wine. Some believe that it is young only a few days after the end of the stage of rapid fermentation, some give it several months of youth before the start of a new stage of life - the ripening phase.

There is no clear answer to the question of how long homemade wine should ferment. The process can take from 1 to 3 months, depending on the temperature, the amount of sugar in the wort and the quality of the yeast.

Let's look at the general points that a novice winemaker should know about these three pillars of successful fermentation. Knowing them, you can independently find answers to questions about what to do and how to make the wine play a second time if it does not ferment.

Kit one: temperature regime

The optimal temperature for wine fermentation is considered to be in the range of 15–25°C; for white wines, the best temperature is 14–18°C; for red wines, 18–22°C. At what specific temperature the wine should ferment is decided by the winemaker, focusing on the behavior of the wort and adhering to the ranges specified by the recipe.

When selecting the temperature, it is important to take other factors into account. The wort is rich in sugar, cold, the bottles are small, therefore the temperature should be high - 20 °C. The wort is sour, warm (above 12 °C), slightly sweetened - 15 °C is enough.

At a low temperature of 9–10 °C, fermentation is also possible, but it will take longer.

High temperature (above 25 °C) may only be useful at first. For a mixture that already contains some alcohol, this temperature is harmful.

When making at home, it is difficult to regulate the temperature. But there are examples when wine was successfully produced from not very sweet raspberry jam, first left at room temperature and then placed on a cool winter balcony.

Their quantity and activity determine how correct and fast the fermentation process will be. In turn, the amount of yeast is determined by many factors: the already mentioned temperature, the duration of access of air to the wort and, finally, the quality of the wort.

When it comes to grapes, winemakers know that fermentation of must from grapes grown on fertile, rich soils will be more vigorous and at the same time smoother. On average, the richer and more nutritious the composition of the starting material, the more active and rapid the fermentation process will be.

The quality of yeast also varies. PWD (pure cultures of wine yeast) behave more actively and smoothly, wild yeast is more unpredictable.

During the fermentation process, yeast cells settle to the bottom, blocking the access of air by being at the very bottom - inert zones are formed that slow down the process. Stirring them periodically with a spatula will help speed up the process, so as to destroy the layers. To destroy them, it is enough to also throw in a few fresh berries. Sometimes, to speed up fermentation, it is recommended to ventilate the wort, providing the fungi with oxygen at the initial stage.

Whale three: sugar levels

Wine made from a sweet source, such as wine made from jam, does not need additional sweetening. Only natural sugars contained in fruits and berries can be used. In ready-made recipes, it is difficult to indicate exactly all the parameters on which the sweetness of berries and fruits for wine depends: their degree of ripeness, variety, harvest time, time from harvest to the moment of use. Therefore, the expected sweetness of the wort does not always correspond to the real one, and yeast fungi, which require sugars to reproduce, may simply not have enough nutrition.

These are general points that should be understood before using any recipe. What to do if grape or berry wine does not ferment or has stopped fermenting - you need to look for the answer to this question yourself, including your own instinct. It’s not for nothing that many winemakers call making wine a creative endeavor, and even claim that they enjoy the process more than the result.

All possible difficult issues and ways to solve them are discussed below. But this does not mean that there is only one reason why your wine does not ferment; there may be several of them.

You should not think that installing a water seal automatically means the start of fermentation. The wine will begin to ferment in a few days. Three days before the start of the process is normal. The period depends not only on the type of yeast, but also on the amount of sugar, temperature and raw materials.

For example, jam wine, which is popular at home, often tests the patience of novice winemakers. To begin processing sugar, yeast needs to become accustomed to a new environment.

If bubbles indicating the onset of fermentation have not appeared after 72 hours, then problems have indeed arisen in the wine preparation procedure. Sometimes, if the room is cool, it makes sense to wait longer - 5 days.

Here we will look at all the possible reasons why wine does not ferment, and we will provide ways to solve each problem. Here you can find answers to the question why the wine stopped playing ahead of time and what to do to stimulate the process.

The room is not warm enough (less than 18–25 ºC), perhaps the container is in a draft. In walk-through rooms there are often low drafts that are invisible to humans. At temperatures below +16 ºC, yeast fungi “fall asleep”; in heat (above 25 ºC) they die. Is it possible to save wine that has been left at the wrong temperature and has not started to play? Yes. Move the jar to a suitable place, add live yeast or starter.

Particular attention is paid to low temperatures, they can greatly slow down the process. Wine under a glove can ferment in a warm place for only a few weeks, in a cool place - up to several months. If you have come to the conclusion that the problem is the coolness, is it possible to move bottles of wine to a warmer place to speed up its preparation? Yes. Just make sure that the temperature in the new room is not too high.

There is a caveat when using a pure yeast culture. Such yeast is not added to the main container, but a starter is prepared for faster activation: 1 tbsp per glass of wort. l. sugar, add yeast to this nutrient medium, wait 40 minutes. The finished starter is introduced into the main wort. It is necessary to ensure that the temperature of the starter and wort in the main container is close. Even a slight difference of 5–7 °C is traumatic for fungi, and they die.

There is little sugar in the wort. In this case, the yeast simply has nothing to feed on, they do not reproduce, alcohol is not produced, and the process does not proceed. Sugar should make up from 10 to 20% of the wort volume. To check whether the level of sugar content is sufficient, it is best to purchase a special device - a hydrometer (or saccharometer). It is inexpensive - about 300–400 rubles. However, if it is not there, all that remains is to use a very inconvenient subjective method - taste. If homemade wine does not ferment for this reason, you need to add sugar.

After adding sugar, the liquid is thoroughly mixed until dissolved. Even better: drain 1 liter of wort, dissolve the required amount of sugar in it, and pour the resulting syrup back into the main wort.

It would be optimal to initially calculate the amount of sugar per kg of raw materials as accurately as possible, and not blindly trust the recipe. There are special formulas.

If the wine stops fermenting after sweetening, then perhaps there is too much sugar, in which case it acts as a preservative. The wort should be diluted with warm filtered water.

It is advisable to adhere to the rule of gradually adding sugar. The total amount, calculated based on the type of raw material and the degree of sweetness of the finished drink (sweet, semi-sweet, dry), is divided into four doses. 2/3 - before fermentation begins. Divide 1/3 into three equal parts and add it to the wort after 4 days, a week and 10 days from the start of fermentation.

What to do with fermented homemade wine? Usually, by fermentation of the finished product, they mean a completely different fermentation - bite. Acetic acid bacteria break down wine alcohol into water and acetic acid. Within 3–5 days, the wine acquires an unpleasant sour taste. A sour drink can no longer be saved. This trouble can only be prevented. In industrial production, sulfidization (sulfur treatment) is used.

Not enough yeast. This problem often arises when they try to make wine with “wild” yeast, that is, those that were on the surface of the berries. There might not have been enough of them initially, or they might have died (for example, in the heat). If the wine does not ferment well for this reason, then it is enough to buy wine yeast in specialized stores. It is also possible to add dark, unwashed raisins. It is possible to prepare sourdough, but it will take quite a lot of time. Or you should put the starter in advance: 200 g of raisins, 50 g of sugar, pour 2 glasses of warm water, cover with a gauze stopper, and keep in a warm, dark place for 3-4 days. The finished starter can be stored in the refrigerator for up to 10 days.

A nuance for those who work with pure cultures of wine yeast. Before adding them, the wort is often sterilized with sulfites. And this is where patience is needed: you cannot add yeast immediately after processing; you need to wait a day for the sulfur to evaporate from the liquid. During this day, the container with the wort is covered only with gauze.

Little oxygen. Quite a common mistake for beginners. The fermentation process consists of two periods: the first is short and the second is long. At the first stage, air (oxygen) access is important; tightness is needed at the second stage. If there is too little oxygen during primary fermentation, the yeast becomes nutrient deficient and stops multiplying. That is, at first there is no need for a water seal; it is enough to cover the neck of the container with gauze folded in several layers. If the water seal is already on, simply remove it and replace it with gauze.

Lots of oxygen. This problem occurs during the second stage of fermentation. Here, on the contrary, tightness and only small access for the release of carbon dioxide are important. If the size of the holes is too large, too much oxygen will enter the wort, and this leads to oxidation of the product - it will be impossible to save the sour drink. It is best to use a medical glove as a water seal, which is placed on the neck of the vessel. To release carbon dioxide, it is enough to make a small puncture on one finger with a thin needle. This type of water seal is easy to control. The glove has deflated, which means the fermentation process has stopped. Either the puncture is too large and the glove needs to be replaced, or the joints should be checked, perhaps carbon dioxide is escaping in other ways.

A convenient way to control air access are single plastic or glass blockers with two flasks and a hose. A sulfite solution is poured into each blocker flask a little less than halfway, and the end of the hose is dipped into the wine. Carbon dioxide sequentially passes through the hose through the first flask (or chamber), then through the second. If the gas pressure has decreased and a vacuum has formed, the sulfide solution moves into the first chamber; it is urgent to add wine to the container.

What to do with fermented jam? This is exactly how winemakers are often born: by chance a suitable source turned up, and now the beginner is working magic with gloves and studying the technology of preparing alcoholic beverages. And then he wonders why the wine from the jam does not ferment at a normal pace, ferments for a long time, or the process has stopped. Possible error in this case: the raw material may be too thick. In a jelly-like environment, it is difficult for fungi to reproduce. Those who make wine from pulp, that is, from skins and seeds, may face the same problem.

Solution: if the wine does not ferment for this reason, you should add clean, filtered, warm water. If the pulp was pressed (the juice was used for primary wine), then the amount of water should correspond to the amount of juice removed. Be sure to pay attention to whether there is enough yeast for the new quantity.

This is a common occurrence among those using wild yeast. The surface of the must becomes covered with a film, an odor appears, and the wine does not play. Mold is also mushrooms, but not the ones you need. They begin to multiply due to the entry of pathogens into the wort (there were rot particles on the berries) and favorable conditions for them (high temperature, 22–28 ºC, high humidity, above 85%, low alcohol, low acidity of the starting material). Alas, if it is severely infected, it is better to throw away the wort. Not only will the finished product in this case have an unpleasant taste, but such wine can cause poisoning.

If the solution is not yet heavily contaminated, it can still be allowed to ferment. Remove all moldy areas and then pour the concentrate into a fresh container. Make sure that the top layer does not get into the new dishes, so it is better to pour through a rubber tube. The wort is boiled at a temperature of 70–75 °C for several minutes, left to cool at room temperature, and then stabilized by adding fresh juice and sugar. If there is a lot of mold, removing its visible parts will not help; the drink is already contaminated.

To prevent mold from appearing, use prevention methods: thoroughly sterilize all elements in contact with the material, wash your hands, carefully select raw materials - remove berries even just with barely noticeable dark spots. The berries are not washed, but it is not difficult to ensure the cleanliness of all objects in contact with them.

It is very risky, from the point of view of mold, to make wine from pulp. When floating, the pulp comes into contact with oxygen, which can lead to the development of unwanted fungi. Stir the wort so that the pulp sinks back. It was already said above that the wort should not be too thick. But it should not be too liquid either, this provokes frequent floating of “solid particles”. Too low acidity also contributes to the appearance of mold; you can add a little citric acid. And, of course, carefully monitor the level of oxygen access to the future drink.

The wine does not ferment. What to do?

Wine or how to awaken the fermentation process

How wine ferments

Fermentation began and then abruptly stopped

A situation where the wine has stopped fermenting can also occur. The process has started successfully, the wort is in the second stage of fermentation, and then the process suddenly stops. There are two reasons for this. The first is that homemade wine does not ferment because the liquid is contaminated with microorganisms that suppress the proliferation of yeast fungi. In addition to mold, there are a lot of other “creatures”: viruses, bacteria that cause diseases that are dangerous for homemade wine. In this case, there is little chance of saving the product.

The second reason why wine does not ferment is that there is already too much alcohol in the liquid. Fungi die if the alcohol content is more than 14%. If this is the case, the wine will begin to ferment after adding warm water, yeast and checking the temperature. If balance is reached, the process must continue.

If no hissing is heard, no bubbles are visible, the glove has fallen off, then the fermentation procedure may have already completed successfully and the wine is ready. Ready dates are as follows:

• Wild yeast – 20–30 days. In ideal conditions (warm, plenty of nutrients) – 2 weeks.
• Pure yeast cultures are able to process all the sugars from the wort - in 5 days or a week.

If berry wine stops fermenting after a week, what should you do? Taste it; perhaps the fermentation process was so successful that it has already been completed. The finished drink will not be sweet; it has a bitter-sour harmonious taste without pronounced sweetness. You can use a hydrometer. The specific gravity of the wine ready for the next stage is 998–1010 g/dm3. This drink is clarified and sent for quiet fermentation in cooler conditions.

If the wine at home stops fermenting after a week, but still remains syrupy and sweet, then the process has stopped ahead of schedule. Analyze the possible causes from the list above and take measures to stimulate fermentation. It is not recommended to drink unfermented wine.

A simple answer to the question of why wine does not ferment and what to do in general is impossible. It all depends on the stage at which the stop occurred and the specific conditions (temperature, recipe, type of yeast). To find the exact cause, analyze all the parameters that could affect the behavior of the yeast. In general, a winemaker's flair is not so much a natural talent as it is experience.