Content

• Steps
• Method 1 of 4: Explore Milk
• Method 2 of 4: Heat the milk in the microwave to check if it has spoiled
• Method 3 of 4: Check the acidity of the milk
• Method 4 of 4: Extend the Life of Your Milk
• Tips

Milk is rich in vitamins and minerals, as well as protein, healthy fats and carbohydrates. However, sour milk will give you nothing but an upset stomach. Even if the date on the package suggests that the milk should still be good, there are various factors that can contribute to it spoiling prematurely. To test the freshness of milk, examine its smell, consistency and color, test it by heating, or see if it reacts with baking soda.

Steps

Method 1 of 4: Explore Milk

1. 1 Smell the milk for unpleasant odors. Smelling milk is the first, and perhaps the most obvious, way to know if it has gone bad. Fresh milk does not smell at all. But sour, on the contrary, exudes an unpleasant aroma. If, after smelling the milk, you immediately recoil or feel disgusted, most likely it has deteriorated.
   • Even if the milk looks fine overall, but smells so bad that you recoil when you sniff it, it's best not to drink it.
   • If you find it difficult to determine if there is a smell, ask someone else to smell the milk to be sure, or use other methods to examine or test.
2. 2 Check the consistency of the milk for lumps or clots. Fresh milk is a light liquid that flows evenly. The consistency of milk depends on the fat content - cream or whole milk is thicker than the non-fat version. However, any milk must flow and flow evenly.
   • If you notice any clots in the milk, then it is spoiled. To see the clots, you can swirl the milk in the container, as they tend to settle at the bottom.
   • You can also inspect the inside of the milk carton. If there is a thick sediment on the inside, the milk may be spoiled.
3. 3 Check if the milk has changed color. Pour milk into a clear glass and hold up to the light. If the milk is still good, it will be natural, pure, white in color. But sour, as a rule, dull or has a yellow tint.
   • If you find it difficult to determine the color of the milk, place a white piece of paper behind or next to the glass and compare. If the milk has a yellowish tint, it is most likely spoiled.
4. 4 Determine if the milk has remained at room temperature. If you want milk to stay fresh, it must be kept cold. If left at room temperature for an extended period of time, it may deteriorate, regardless of the expiration date. If you know the milk has been left at room temperature for more than 1 hour, chances are it has gone bad.
   • If you live with your family or roommates, you may not be able to tell if the milk was left at room temperature. Just ask around and try to get reliable information.
5. 5 Make sure that no more than 7 days have passed since the expiration date. If stored properly, milk will be good for 7 days after the expiration date printed on the package. However, if the expiration date has passed, and the milk is completely forgotten, it is highly likely that it has deteriorated.
   • The shelf life of milk depends on the amount of fat and lactose in it. Whole milk can only be stored for 5 days after the expiration date. But lactose-free or skim milk can stay fresh for up to 10 days.
   • If your milk has expired more than a week ago, it is best to throw it away, even if it looks normal and does not smell.

Method 2 of 4: Heat the milk in the microwave to check if it has spoiled

1. 1 Pour milk into a microwave-safe glass. If you have studied milk and are still not sure if it is sour or not, you can check it. Pour a small amount of milk into a clean glass, about 2.5 cm high.
   • Check only a small amount so the leftover milk can be used if it is still good.
2. 2 Heat milk in the microwave for 30-60 seconds. Place a glass of milk in the microwave and heat for 30 seconds to one minute. If you have a large, high power microwave, use a shorter period of time.
   • If you don't know how long to heat milk, start with 30 seconds. If it hasn't warmed up in 30 seconds, leave it on for another half minute.
3. 3 Throw away any lumps or lumps of milk. Stir the milk to check if it is runny or thickened. If the milk has lumps or lumps after heating, this is a sign that it has deteriorated.
   • Milk curdles because, due to the high acidity in the sour product, the proteins begin to stick together, creating clots.
   • It is normal for a thin film to form on top of the milk when heated. This does not necessarily mean that it has deteriorated. However, after removing the film, the heated milk underneath should be runny if it is still good.

Method 3 of 4: Check the acidity of the milk

1. 1 Place 1 teaspoon (10 grams) of baking soda in a saucer. You don't need a lot of baking soda for this test, just enough for you to see how it reacts to milk. Make sure the baking soda is fresh. Otherwise, she may not give a reaction.
   • In general, do not use baking soda for this test if the expiration date on the package has passed.
2. 2 Add a few drops of milk to the baking soda. Use milk straight from the container, not something that has been previously heated. You only need 1 or 2 drops of milk to determine how it interacts with baking soda.
3. 3 The baking soda will begin to bubble if the milk turns sour. However, it does not give any reaction with fresh milk. Sour milk has a higher acid content, which causes the baking soda to release bubbles of carbon dioxide. The more bubbles, the more sour milk. If you see any bubbles, the milk is most likely unsafe to drink.
   • Even if the milk looks normal or smells good, do not drink it if the baking soda is bubbling.

Method 4 of 4: Extend the Life of Your Milk

1. 1 Store milk below 4 degrees Celsius. Milk should be kept in the refrigerator at all times.If you leave the package on the table at room temperature for a long period of time, the food will deteriorate faster.
   • If milk is stored in the back of the refrigerator, it will definitely stay cold. If you keep milk in the refrigerator door, it will often be exposed to varying temperatures when the door is opened and closed. This can shorten its shelf life.
2. 2 Do not expose milk to light. Milk from clear, glass or plastic packaging does not last as long as milk in cardboard or colored plastic containers. Milk deteriorates when exposed to light, and even temporary exposure to opening and closing the refrigerator door will shorten the shelf life of the product over time.
   • If milk is in clear packaging, store it in the back of the refrigerator “protected” by other items to reduce exposure to light.
3. 3 Close the milk container tightly. Fresh milk that is exposed to air can spoil even if stored properly. Make sure the cap is screwed on tightly. In most cases, milk should be left in the original packaging intended for storage.
   • If the original packaging is damaged, pour the milk into a jug or other container with a secure lid. Do not leave milk in an open jug or glass, even if you store it in the refrigerator. Rewrite the data from the original packaging to the new one.
   • If the cap is loose, place cling film or wax paper over the neck, then screw the cap back on. This will help ensure that the packaging is as tight as possible.
4. 4 As a last resort, freeze the milk. Milk can be stored in the freezer for up to 3 months. If you live alone or don't use milk often, this can be an economical option to keep you from wasting your product.
   • To defrost milk, place it in the refrigerator or place a bottle or box under cool water.
   • When frozen, milk will slightly change its texture and color. Once thawed, it may even have the consistency and color of sour milk, although technically it will still be good. The taste can also be less pleasant.

Tips

• Spoiled milk can still be prepared or used in recipes that specifically require a sour product.
• Artificial milk, such as almond milk, can stratify during storage. It `s naturally. If you shake it, it will be all right. If the consistency is not restored after shaking, it may have deteriorated.
• Sometimes there are small lumps in kefir. They should not be confused with clots indicating that the dairy product has gone bad.