Boiled condensed milk in a jar recipe. Cooking condensed milk without a can - a unique and simple way

Condensed milk is one of the most favorite products for those with a sweet tooth. Many people associate the smell and taste of condensed milk with childhood and their fondest childhood memories.

In addition, condensed milk is a universal product. You can eat it just like that, or add it to a variety of dishes and baked goods. Very tasty and very easy to make. There are a huge number of ways to cook it. But you need to strictly follow the cooking rules and know how long to cook the condensed milk. Otherwise, instead of a delicious dessert, you can end up with a lot of problems. The fact is that if cooked incorrectly, the jar may explode. And this will not only spoil the product itself, but will also add a lot of hassle to cleaning the kitchen.

How long to cook condensed milk

The cooking time for condensed milk depends on the recipe you choose. You can boil the milk, as in a can, without violating its integrity until the end of the entire cooking process, or just the condensed milk itself, after first removing it from the container.

How long to cook condensed milk in a jar

The first method and one of the simplest is cooking in water.

Water is poured into the cooking container, into which a can of condensed milk is placed. It is necessary to ensure that the water completely covers the jar. Place the saucepan on the stove and bring the water to a boil over fairly high heat, then reduce the heat and leave the jar to cook for 2-2.5 hours. As it boils, water is periodically added to the pan. Remember - this is very important. Otherwise, if left without water, the jar may explode.

The second method is to prepare boiled condensed milk using a pressure cooker.

This recipe is for those who like to cook without straining at all. As they say, set it and forget it. There is no need to constantly monitor the water level and cooking time. Fill the pressure cooker with water, place a can of condensed milk in it (the water should completely cover the jar) and bring to a boil over very high heat. After the water has boiled, wait another 10-15 minutes and turn off the pressure cooker. Do not remove the jar until the water has completely cooled.

If you have very little time or you simply don’t want to monitor the process of preparing condensed milk for 2 hours, the option of preparing condensed milk in the microwave is more suitable for you.

How long should you cook condensed milk in the microwave?

You won't believe it - only 15 minutes. Yes, it is in such a short period that you can prepare this delicious delicacy. Well then. Let's say a huge thank you to the creators of this miracle of technology and get to work. Open a can of condensed milk and pour its contents into a deep container (the container must be suitable for use in a microwave oven) and, setting the power to medium, start the microwave for 15 minutes. During cooking, the condensed milk will need to be stirred several times, as the radio waves emitted by the oven heat the liquid unevenly.

Some useful tips for those with a sweet tooth.

Buy only high quality. A high-quality product contains only milk and sugar. Condensed milk, with many impurities, is not only harmful to health, but when cooked it can give a completely unexpected result. For example, curl up into lumps or “delight” with crystallized grains of sugar.

The longer condensed milk is cooked, the darker and more viscous it becomes in consistency.

If you cook condensed milk in a jar, then after completing the cooking process, you need to let the water cool completely and only then can you remove the jar from it. Do not cool with cold water under any circumstances, otherwise the taste of the dish may be greatly affected.

Now you know how long to cook condensed milk. So all that remains is to wish you bon appetit.

How long does it take to cook condensed milk in a jar until it turns brown? Condensed milk, or condensed milk, is concentrated cow's milk from which the water has been removed, usually with added sugar. This is a sweet, thick product with a caramel flavor; The most common type of packaging is a tin can, which allows condensed milk to be stored without refrigeration for a year before opening.

If you fill a can of condensed milk with water and cook it over low heat, you will get boiled condensed milk. A lesser known name is dulce de leche; literally translates from Spanish as “milk jam.” Today we will talk about how long it takes to cook condensed milk in a jar.

It’s not for nothing that boiled condensed milk is considered a universal product: it is spread on toast, creams for cakes with butter, sour cream or cream are made from it, used for decoration, stuffed, coated with it on cookies, added to tea or coffee, or eaten just like that.

DoughVed advises. Even the most novice cook can figure out how to cook condensed milk in an iron can at home, but even in such a simple recipe it is necessary to adhere to some key recommendations so that the can of condensed milk does not explode during cooking.

So, there are two basic rules that you must remember every time before you cook condensed milk in a tin can at home.

Rule No. 1: Water must completely cover cans of condensed milk.

There are two reasons to strictly adhere to this recommendation during cooking.

Firstly, water does not physically heat up to more than 100 o C. Accordingly, cans containing condensed milk and completely immersed in water will also not heat up above this temperature. Even if the jars heat up a little more from contact with the bottom of the pan in which they are boiled, the surrounding water will “take” the additional heat onto itself.

However, allowing some of the water to evaporate exposes the jars to open air, causing them to overheat. Due to significant heating, caramelized milk expands and begins to put pressure on the walls of the jar, which may not withstand the pressure and burst.

Secondly, the water in this cooking method actually acts as a water bath. When the jars are completely immersed in water, the caramelization process of the milk is more uniform.

That is why throughout the cooking you need to constantly ensure that there is always enough water in the pan.

Rule #2: Cans must be completely cool before opening them.

In fact, the second rule directly follows from the first: the caramel formed during cooking increases in volume due to heating, so if you open the can immediately, without waiting for it to cool, you can get a whole fountain of scalding hot condensed milk.

To avoid burns, always cool jars to room temperature before opening them.

How long does it take to cook condensed milk in a jar?

10 minutes to prepare

3 hours to prepare

315 kcal per 100 g

Boiled condensed milk at home - how and how long to cook in a tin until brown.

Although the process is quite simple, if you follow all the rules, it takes a lot of time to cook condensed milk in a can until it turns brown, so it is better to cook at least 3-5 cans at once and store them ready.

For more information on how to store iron cans of boiled condensed milk at home, read the tips at the end of the recipe.

Ingredients

condensed milk in cans;
water in sufficient quantity.

Preparation

Prepare the required number of cans of condensed milk. Remove the paper labels from the jars and place them in a pan large enough to hold all the jars in one layer. It is better to stack the jars while lying down, since if you place them standing, they will float during cooking and create noise for three hours. In addition, in this case the layer of water above the jars will be thicker.
Fill with enough cold water to completely cover the jars. The water level should be at least 2-3 cm higher than the cans, the more the better.
Place the pan over high heat and bring to a boil. After the water boils, cook for 2.5-3 hours. The boiling should not be too strong - the hotter the water boils, the faster it evaporates. The time depends entirely on how dark brown we want the boiled condensed milk to be. The longer milk is boiled, the darker it becomes. The optimal time is from two and a half to three hours.
We constantly monitor the water level in the pan, check whether the jars are hidden with water at least every half hour, preferably more often. As the water boils, add boiling water.
After the required time has passed, carefully, so as not to burn your hands, remove the jars from the pan using tongs or a slotted spoon.
Place the jars on a towel and leave until completely cool. The jars are very hot, so despite using a towel, you need to place them on a heat-resistant surface.
It is usually recommended to leave the jars for at least 10-12 hours to allow them to cool completely, but there is a faster way to cool the condensed milk. Drain the hot water from the pan and return the jars to it. Place the pan in the sink and fill with cold water. As the water heats up, change it to cold water until the jars are cold to the touch. Open it carefully, as the caramel in the middle is still quite warm.
Mix the milk with a spoon directly in the jar and use dulce de leche at your discretion, for making desserts, creams or.

In principle, it is not necessary to remove the labels, but during boiling they become soggy and small pieces of paper stick to the bottom of the pan and jars, which will be quite difficult to clean after cooking.
To ensure that boiling water is always on hand in case the water in the pan suddenly boils over, boil the kettle each time immediately after pouring out the previous portion.
Unopened jars are stored at room temperature for a very long time; opened jars should be stored in the refrigerator, tightly closed with a lid or cling film, for no more than a month.

All housewives are well aware that the best quality sweets are those made with their own hands at home. Therefore, the question: how long to cook condensed milk in a jar is always very relevant; The store-bought equivalent of the boiled product, alas, is in many ways inferior to the home-made product.

That’s why cooking delicacies at home is the best preparation option, allowing you to make the treat the right consistency, color and taste.

How to cook condensed milk in a tin can: “Classic” recipe

Cooking condensed milk is quite simple if you know the basic secrets of cooking and the features of the product itself. When determining the cooking time, remember that the decisive factor will be the fat content of the milk.

If condensed milk has a fat content of 8%, then you need to cook it in an iron can for 1.5-2 hours, if the percentage of fat content in the milk is higher, then the time needs to be increased to 2-2.5 hours.

Classic rules for cooking condensed milk in a can:

Pour water into a saucepan and place the container on the fire.
We lower the jar into water, but so that the liquid completely covers it.
Bring water to a boil over medium to high heat. As soon as the water boils, reduce the flame to almost a minimum and continue to cook the condensed milk further. The water in the pan should not boil too much.
During the cooking process, carefully ensure that the water does not completely evaporate, otherwise the jar with the sweet contents will “explode”. As the liquid evaporates, you need to gradually add a new portion of water into the pan.

Immediately after cooking, do not remove the jar of condensed milk from the hot water. You want the milk to cool right in the pan. Do not put it in cold water. On average, it may take from 1 to 2 hours to cool down, but this method will protect the jar from damage.

During the cooking process, you only need to add hot water to the pan. Sudden changes in temperature can cause the jar to burst.
Therefore, in parallel with the container for cooking condensed milk, place a container of clean water on the stove, which, when heated, you will gradually add to the pan where the tin can of condensed milk is boiled.

In order to correctly answer the question: how long does it take to cook condensed milk, you must first answer yourself - what kind of condensed milk do you want to get and for what purpose do you plan to use it.

If you like sweetness that is not too thick or you want to use it as a basis for making chocolate sausages, cakes, pastries, etc., then you need to prepare semi-liquid milk.

To do this, cook condensed milk in an iron can for no more than 1 hour over moderate heat.
Planning to get a moderately thick consistency, with a pleasant milky tint, you will need to cook the condensed milk for about 2-3 hours.
To obtain a very thick mass, the color of fresh coffee with milk, the cooking time will have to be increased to 4 hours.

The condensed delicacy is not always sold in cans; sometimes you can find it on store shelves in glass containers.

How to cook condensed milk in this case and is it even worth cooking it in a glass container? Of course, it’s worth it, moreover, this cooking option has more advantages than cooking boiled milk in an iron can.

During the boiling process, metal containers form oxides that are unsafe for human health.

In addition, under the influence of hot temperatures, the tin coating of the can is destroyed and harmful substances are released from it directly into the condensed milk.

That is why it is preferable to cook your favorite delicacy not in a tin can, but in a glass container, or without a can at all - in some kind of enamel pan or bowl.

How and how much to cook condensed milk in a glass jar

Place a glass container with condensed milk in an empty saucepan.
Cover the container loosely with a lid. It is advisable that the lid be larger in diameter than the diameter of the glassware itself. If you close the container tightly, it may burst during cooking.
Pour enough cold water into the pan so that it reaches the level of the condensed milk in the jar.
Place the pan on the fire and wait for the water to boil.
As soon as boiling bubbles appear on the water, reduce the flame to a minimum.
In this mode, cook the product for 3.5 hours. There is no need to stir condensed milk during cooking.

Keep an eye on the liquid in the pan and do not forget to add hot water to it approximately every 20-30 minutes. When the delicacy is cooked, leave it to cool in the pan.

Using the principle described above, it is convenient to cook condensed milk on tap. But what to do if the bottled product was sold to you not in a glass jar, but, for example, in a plastic bottle.

Is it possible to boil condensed milk in such a container?

It is possible, but it is highly not advisable to do this. There is a fairly high risk that the plastic will melt during cooking, and harmful substances will begin to be released from it, which can be hazardous to health.

That is why it is better to cook purchased condensed milk in bulk in a glass container, or even cook it without a jar, for example, in the microwave.

One of the easiest and fastest ways to prepare condensed milk is to boil milk in the microwave. The time needed is 15-30 minutes, no more, everything will depend on how thick the product you want to achieve. After all, the longer you cook, the thicker it becomes.

How to make boiled condensed milk from simple condensed milk

To prepare the dish, first of all, you need to pour the milk into a bowl or any other container that is suitable for cooking in the microwave.
Do not use metal containers under any circumstances; they are not suitable for this.
After pouring the condensed milk into a bowl, cover it with a lid (not tightly) and place it inside the microwave for 15-20 minutes.
Cook on medium power and do not forget to stir the product from time to time. It is important that the dessert cooks evenly and that nothing burns during the process.

All the time you can monitor the result of cooking and determine by color whether the condensed milk has been cooked or not. By controlling the result, you yourself will decide how long to cook the condensed milk - 10-15 minutes or about half an hour.

You can quickly cook condensed milk at home using a modern pressure cooker. To do this, you will need 10 minutes of time, a can of condensed milk that meets all GOST standards, and the pressure cooker itself.

Cooking steps

Place the jar in a pressure cooker and fill it with water so that the container with the sweetness “drowns” in the water.
Bring the liquid to a boil and boil the milk for 10-12 minutes.
Immediately after cooking, do not open the lid of the pressure cooker; wait until the jar has completely cooled in the water.

Carefully monitor the temperature of the water in the pan during cooking. The liquid should not be allowed to overheat, as this may cause the condensed milk to curdle or the can to become deformed.

Alternative ways to cook condensed milk at home

How to boil milk in a water bath

A less popular, but quite effective, method of preparing boiled condensed milk is a water bath. This method is not so popular due to the fact that it will take at least 5 hours to cook. This is long and quite tedious, given that you have to constantly monitor the water in the pan so that it does not completely evaporate.

But if you still decide to use steaming, then you will need to pour the condensed milk into an enamel pan, and then place it in a container with boiling water.

A saucepan of water should boil over medium heat; at this rate, the condensed milk will cook for 5-7 hours. The exact time directly depends on the speed of preparation of the product.

Condensed milk cooked in a slow cooker

You can also cook the sweet in a slow cooker or in a pressure cooker. The cooking technology in a multi-unit is very similar to classic cooking in a regular saucepan.

Read more about cooking condensed milk in a slow cooker in the articles on the website.

As you can see, it is very easy to get a finished boiled product at home. Now you know how and how much to cook condensed milk in a jar and without it. The simple cooking recipes we have given will allow you to cook the favorite dessert of adults and children with high quality.

Cook with pleasure and enjoy every spoonful of homemade delicacy.

Bon appetit!

Condensed milk is rightfully considered a universal dish; it is added to cupcakes, pastries, and pies. The delicacy can be used as an independent dish as a snack for tea. Condensed milk is often used with pancakes; children and adults love it. Store-bought formulations are packed with additives and preservatives that extend shelf life and improve viscosity. For this reason, experienced housewives prefer to prepare the delicacy themselves. We will highlight the most delicious recipes and provide practical recommendations.

It is better to prepare condensed milk at home using fresh whole milk. In cases where purchasing such an ingredient is difficult, use pasteurized milk with a high degree of fat content (3.2% and above). If desired, you can replace milk with heavy cream (25%), observing the proportions.
To prepare condensed milk, it is very important to choose dishes. The best option is a thick-walled and thick-bottomed pan (steel, aluminum or cast iron). To prevent the composition from burning, you can also use a steam bath.
The classic recipe and its variations involve the use of granulated sugar as the main component. If desired, it can be replaced with powdered sugar; it dissolves many times faster. The main thing is not to violate the quantitative ratio (g). In addition, the powder contains starch, which gives the condensed milk the necessary viscosity.
To obtain a homogeneous mixture without inclusions or lumps, baking soda is added to the classic recipe. It also emphasizes the taste of condensed milk, making the delicacy richer and brighter.
For variety, you can add cocoa powder to condensed milk. Children like this variation, but the final product may be slightly bitter (if you add too much cocoa). In this case, the condensed milk will acquire a characteristic brown tint; it can be used as a decoration for a cake or pastries.
To make condensed milk sweet, use cane sugar rather than beet sugar. At the same time, it can be crushed into powder to improve viscosity and give a porous consistency.
Ready condensed milk must be stored in a glass container with a tight-fitting lid. A heat-resistant container for storing food or heating food in the microwave is also suitable.
You can make “Iris” candies from condensed milk. Simply pour the final product into candy or ice molds, place in the refrigerator and cool until hardened.
The duration of cooking condensed milk directly depends on the amount of sugar used in the cooking process. The more bulk composition you add, the faster the process will proceed. At the same time, the dish will turn out sickly sweet.
You can add high-fat butter to homemade condensed milk. As a rule, this move is used by confectioners when they want to make condensed milk tender and viscous (for cupcakes, cakes, muffins, etc.). However, it is worth remembering that the presence of such an ingredient in the composition reduces the shelf life.

How to cook condensed milk: a classic of the genre

baking soda - 3 gr.
granulated sugar - 580 gr.
milk with fat content from 3.2% - 1.2 l.
vanillin - 20 gr.
drinking water - 80 ml.

As mentioned earlier, cooking condensed milk should be done in a non-stick pan with thick walls and bottom. Milk in combination with sugar/powder will first begin to foam and then stick to the dishes. If the bottom is too thin, the composition will burn and become unusable. In cases where it is not possible to use a thick-walled pan, the mixture will have to be stirred intensively (do not leave the stove).
Once you decide on the container, wash and dry it. Mix granulated sugar (preferably cane) with vanillin, add drinking water, mix with a wooden spatula.
Turn the burner to between low and medium and place the pan on the stove. Stir with a whisk or spatula until the sugar crystals are completely dissolved and the mixture becomes homogeneous.
After preparing the vanilla syrup, begin to slowly pour in the milk, having previously cooled it to room (!) temperature. While stirring the mixture, do not reduce the heat, bring the mixture to a boil.
After the first bubbles appear, reduce the burner to minimum power and add baking soda. Begin stirring the mixture vigorously as it will begin to foam and burn.
Simmer the condensed milk for about an hour, cover with a lid, but do not completely cover the opening of the pan. During cooking, the composition must be stirred every 7-10 minutes. Don't forget to skim the foam off the sides and then put it back into the pan.
After a certain period of time, the mixture will acquire a light chocolate shade. If you set a goal to prepare condensed milk with a liquid consistency, remove it from the stove at this stage.
If you need to get thick condensed milk, simmer it for another 30-40 minutes. Determine readiness by color, taste and consistency. The longer the composition is cooked, the sweeter, more viscous and darker it will be.
At the end of cooking, cover the dish with a lid and leave to cool at room temperature. Then pour the condensed milk into a glass jar or heat-resistant container and seal.
Place the final product in the refrigerator. To increase storage time, scoop up the mixture with a dry and clean plastic spoon, then return it to the storage chamber.

powdered milk - 375 gr.
granulated sugar (cane) - 1.3 kg.
cream with fat content 27-33% - 1.1 l.
dry baby formula (milk) - 220 gr.
filtered water - 125 ml.
vanilla sugar - 10 gr.

Prepare the dishes for cooking. The pan should have thick walls and bottom, as well as a non-stick coating (preferably). Wash and dry the container, add vanillin and granulated cane sugar, add water.
Place the mixture over low heat, do not bring to a boil; the sugar crystals should not completely dissolve at this stage.
When the mass reaches a more or less homogeneous consistency, remove the pan from the heat. Pour in the cream, add baby formula and dry milk. Place the container back on the stove, turn the heat to low, stir with a whisk until the lumps disappear completely.
Leave the mixture to simmer for 1-1.5 hours. During the specified time, constantly stir the condensed milk and remove excess from the walls, then return it to the container.
When the product turns brown, sticky and sweet, turn off the burner. Cool to room temperature, pour into jars, and place in the refrigerator for long-term storage.

Condensed milk based on butter

milk or drinking water - 320 ml.
dry cream - 500 gr.
granulated sugar (cane or beet) - 270 gr.
butter - 75 gr.

Prepare an enamel pan with a non-stick coating and a thick bottom. Pour water or milk into it, the second option is preferable (the condensed milk turns out tender).
Place the pan over medium heat, bring the liquid to a boil, then remove the pan from the heat. Add dry cream (you can replace it with dry milk), and start whisking the mixture at the same time with a whisk or mixer until it rises 2-2.5 times.
Add cane sugar and butter, softened at room temperature. Whisk again, making sure there are no lumps in the mixture.
Prepare a steam bath: pour boiling water into a wide saucepan, place the container with the composition in it so that the smaller container rests on the handles (the lower parts of the containers do not touch).
Turn on medium heat, stir the mixture and simmer for about 1.5-2 hours. The consistency will tell you that the condensed milk is ready: the paste will become viscous, sweet, and brown.
After all manipulations, cool the condensed milk to room temperature, then pour into containers or jars and seal. Store in the refrigerator door and remove the mixture with a clean plastic spoon.

It's easy to cook condensed milk at home. Use the classic recipe, consider the cooking technology based on milk powder, butter, liquid heavy cream. Add cocoa or vanilla if desired.

Video: how to cook condensed milk

Boiled condensed milk: cooking options.

Varenka is sold in any supermarket and is an indispensable delicacy for lovers of sweet dishes. But it does not always satisfy the fastidious taste of gourmets with a sweet tooth with its quality. The best option is to cook condensed milk yourself. At home, condensed boiled water can be prepared to your liking: thick or thin, dark or light. We'll talk about how to do this correctly next.

How and how long to cook condensed milk in an iron can until it turns brown and caramel in color in a saucepan?

Traditional way

Condensed milk is cooked very simply if you use some cooking tricks and take into account the specifics of the milk itself. The time the product is ready depends on the fat content of the milk, the desired thickness and color of the finished product.

To obtain a milky shade and not too thick consistency, cook:

With 8% milk fat content - 1.5-2 hours
Higher concentration milk - 2-2.5 hours

Thick and dark boiled meat requires longer heat treatment:

For the first version of the product used - 2-2.5 hours
For the second - about 4 hours

Most common cooking method:

Place the jars in a deep bowl, having previously cleared them of the paper label.
Pour in cold water so that it completely covers the jars
Heat to a boil
Then cook over medium heat, taking into account the above recommendations from 1.5 to 2.5 hours
Be sure to ensure that the container is always covered with water.
If the liquid has boiled away, add boiling water.
Once ready, carefully drain the water.
Let the finished product cool for at least an hour without removing it from the pan.

Video: How to cook condensed milk in a jar?

Is it possible, how and for how long to cook condensed milk in an iron can until brown and caramel in color in a slow cooker?

Place the can of condensed milk in the multicooker bowl
Pour water, covering the container with condensed milk at least 3 cm from above
Turn on the “Boiling” function
After the liquid boils (5-10 minutes), switch to the “Quenching” function
Set cooking time - 2-2.5 hours
After the multicooker signal that it is ready, open the lid
Let cool without removing from the bowl for 2 hours.
Open the jar after it has cooled completely

Video: Boiled condensed milk in REDMOND RMC-IH300

How and how long to cook condensed milk in an iron can until brown and caramel in color in the oven?

In the oven, the boiled milk is prepared in a water bath:

Pour water into a fireproof container
Place the can of condensed milk so that the water covers it
Place everything in the oven together
Cook for 2 hours at 200 degrees
The finished product must cool thoroughly before opening.

How and how long to cook condensed milk in an iron can until brown and caramel in color in a pressure cooker?

A pressure cooker allows you to prepare your favorite delicacy in 10 minutes.
Cooking steps:

Place the jar in the prepared pressure cooker pan
Fill the container completely with water
Closing the pressure cooker
Cook for 10-15 minutes
Check periodically to make sure the liquid does not boil away. If necessary, add boiling water
After the set time has passed, do not remove the lid until it cools completely, about 2 hours.

Video: Recipe. How to cook boiled condensed milk in a slow cooker quickly? Just 13 minutes!

Is it possible, how and for how long to cook condensed milk in an iron can until brown and caramel in color in the microwave?

We use a microwave oven

Modern electronic home assistants significantly reduce the process of cooking condensed milk. The time spent on preparing the sweets in question using a microwave will be no more than half an hour.

Preparation:

Since condensed milk cannot be cooked directly in a tin can, we pour it into any suitable microwave-safe container, except plastic and, of course, metal
Cover with a lid
Place in the oven for 2 minutes (power 700 W)
Take it out and stir it
Microwave again, removing every 2 minutes and stirring.
In total, about 8-10 passes are needed for readiness, depending on the capabilities of the microwave and the desired result (thick or liquid, dark or light)

Is it possible and how to cook condensed milk in soft packaging?

Is soft packaging suitable for boiling at home?

You can try cooking your favorite delicacy packed in a soft container, but it’s better not to risk it
Without knowing the strength of the packaging, you can weld the packaging together with condensed milk, which will melt during the cooking process
Therefore, it is better to cook it in the microwave or pour it into a glass container and cook

Is it possible and how to cook condensed milk in a glass jar?

The best cooking option

Preparing boiled condensed milk in a glass container is not only possible, but also has a number of advantages over cooking the product in a tin can:

As a result of heating, a tin container forms harmful oxides that are unsafe for human health.
Hot temperatures destroy the tin coating on the container. The released harmful substances combine with milk, turning it into a not entirely safe product.

Therefore, consider the option of preparing boiled milk in a glass jar:

Place a glass container with condensed milk in a deep saucepan.
Cover loosely with a lid to prevent water from getting in. A tight lid may cause the glass jar to crack.
Pour water into a saucepan, up to the level of condensed milk in jars
Bring to a boil
Reduce heat to medium
Cook for 3-4 hours, periodically adding hot water if it boils over.
Cool without removing from the water

Is it possible and how to cook condensed milk in an open jar?

This option is acceptable if two conditions are met:

Stir the milk constantly to prevent a crust from forming.
Pour in enough water so that when it boils it does not get into the prepared sweetness.

Is it possible and how to cook condensed milk without a can?

Additional, not very common option

Let's consider a less popular (due to the duration), but if necessary, possible method:

Pour the purchased product into a ceramic pan
Place in a larger container with water
Cook at medium temperature, stirring occasionally for about 5 hours (in some cases 7-8 hours)

Without a jar, you can make boiled milk with your own hands from whole (powdered) milk. This option is suggested in a short film.

Video: Varenka condensed milk (Caramel)

When preparing, keep in mind that the taste and quality of the finished sweet are determined by the characteristics of the original product. The naturalness of the purchased preservative is confirmed by the following requirements:

Ingredients: sugar and milk
Not expired expiration date
Marking number 76
GOST quality standard
Undamaged container