With all the restrictions on what you can and can’t heat up or cook in the microwave, it’s no surprise that many may be wondering if they can heat up the milk in the microwave. Whether you need to warm your milk for a recipe, for your hot coffee, or simply to enjoy a warm glass of it, we’ll answer all your questions about heating milk in the microwave.
Milk can be heated or warmed in the microwave, but should only be heated in small increments to prevent the milk from scorching or boiling over. Be sure to use a microwave-safe dish and stir the milk in frequent intervals between each microwaving increment so the heat becomes evenly distributed.
To find out more about what you should know before you microwave your milk, keep reading!
Risks of Microwaving Milk
Before you heat up your milk, you should know the risks of microwaving your milk when done improperly or carelessly. So long as you follow our steps for microwaving your milk, depending on the type of milk, especially the stirring step between increments, you can avoid the following risks.
When you heat milk in the microwave, regardless of what type of milk it is, you risk the water content of the milk getting too hot and causing the milk to boil over, creating a hot mess in your microwave. This is especially true if you leave it in the microwave for too long. If the milk boils in the microwave and you remove it before it boils over, a foamy layer at the top of the milk will be present and can be unpleasant to drink. It can’t be mixed back into the milk.
Another risk of microwaving milk is that the concentrated heat in the microwave can cause the milk to scorch or burn. Ever tried melting chocolate in the microwave, only for it to start smoking? This is because of the milk content in most chocolate.
The scorching and smoking happen when the heating increments are too long and the milk isn’t stirred in between each increment. This causes the milk to taste burnt or unpleasant. Oftentimes, the scorching happens at the bottom of the container, and you may not notice it until you’re already drinking it or you’ve added the milk to your coffee or your baking recipe.
An additional risk of heating milk in the microwave is that the heating can cause an unpleasant film of protein to form on the surface. This film can be stirred back into the milk, or the milk can be put into a blender to break up this film, but doing so can change the texture of your milk. To avoid this, and all the other risks discussed above, be sure to stir your milk in frequent increments during the microwave heating process.
One of the benefits of microwaving milk, however, is that it can actually preserve more of the milk’s natural nutrients than heating it using other methods. This makes microwaving milk one of the healthier ways of heating milk.
Microwaving Pasteurized Dairy Milk
Pasteurization is the process of heating raw milk to a particular temperature for a particular amount of time in order to kill any pathogens and bacteria that can be found in regular raw milk. These pathogens can be found in any dairy milk, including milk that comes from cows, goats, and sheep. Drinking unpasteurized milk can be dangerous, creating sicknesses from the pathogens found in raw milk like Salmonella, forms of E. coli, Listeria, and Campylobacter.
These pathogens can cause disease or illness, and anyone is at risk of such disease and illnesses. All stores and public spaces that sell milk must, by law, follow pasteurization processes. So, that carton of milk you bought at your local grocery store or farmer’s market has most likely already gone through this process. We will discuss how you can pasteurize unpasteurized milk in the microwave later.
For now, you should know how to microwave pasteurized milk in the microwave in a way that avoids any scorching, film, or boiling over. These pasteurized milk include whole milk, 1% milk, 2% milk, and skim milk from dairy cows, goats, and other dairy animals.
Be sure to keep your milk chilled in the refrigerator to keep it from growing any bacteria, and after you’ve microwaved it, be sure to consume or add it to your recipe right away. The most important thing to remember when heating up your milk in the microwave is to heat it very slowly, stirring frequently. To microwave pasteurized milk, follow these directions:
- Pour the desired amount of milk into a microwave-safe glass or container.
- Place the milk on the center of the microwave’s turning dish and close the microwave
- Set it to medium-high power, enter 15 seconds, and press start
- Remove container from microwave carefully
- Stir the milk gently using a metal spoon or stirring stick
- Repeat steps 2-5 a few times until you notice steam rising from the top of the glass/container
Pasteurizing Raw Milk in the Microwave
Unpasteurized (also known as raw) milk can be purchased for animal feed or for consumption at almost any local farm. Raw milk can legally be sold by farmers in every state except Michigan but is advertised only as animal feed. Unpasteurized milk is at high risk of having harmful bacteria that must first be heated out to a certain temperature prior to human consumption, to avoid any foodborne illness or food poisoning.
Pasteurized milk has already gone through this process before it gets put on the shelves of your grocery store, but you can follow a quick process of heating to the correct temperature if you’ve purchased unpasteurized milk.
To pasteurize milk, the milk must come to a temperature of 161℉ (71.7 degrees Celsius) for at least 15 seconds total. This is why a cooking thermometer will come in handy for this pasteurization process. You can heat your milk over the stove or in the microwave for pasteurization. Just be careful when heating in the microwave, because the microwave can cause the milk to heat unevenly or boil over. To pasteurize milk in the microwave, follow these steps:
- Place milk in a microwave-safe glass or container and place it on the center of the microwave turn plate.
- Set time for one minute on high and press start.
- Carefully, remove the glass or container from the microwave.
- Stir the milk using a spoon or stirring stick.
- Take a temperature reading using your cooking thermometer, this will give you an idea of how many times you’ll need to reheat the milk. Keep in mind that you want the milk to reach a temperature of 161℉.
- Place milk back in the microwave, at the center of the turning plate.
- Set time for 15 more seconds and press start.
- Remove glass, stir, then check temperature once more.
- Repeat steps 6-8 one or more times until the temperature has reached 161℉
- Once the milk has reached 161℉, heat the milk one last time for 15 more seconds. Your milk should now be pasteurized.
- Immediately place your milk into an ice water bath (in a large mixing bowl, container, or kitchen sink) to be chilled, then put it into the refrigerator.
Microwaving Whole Milk
Whole milk is the preferred milk of many people, as it is closest to raw milk but has been pasteurized and is without risk of foodborne illness. Whole milk still has all its original fat content, so those looking for more diluted milk or milk with less fat content should opt for 1%, 2%, or skim milk, depending on their preferences.
Many parents prefer using whole milk to give to their young children, which is often introduced to babies at around 12 months to help them wean off of breast milk or baby formula. To help this weaning process go smoothly, and because babies are used to warming milk and may take a disliking to chilled milk, parents will warm the whole milk before feeding their babies. There are many other reasons you may want to heat up your whole milk, including for hot coffee, cooking or baking recipes, or simply for drinking.
You can warm or heat up whole milk over the stove or in the microwave following the same microwave heating process for skim or percentage milk. It is especially important to stir the milk in 15-second intervals during this heating process when giving milk to your baby or young child, as this will help remove pockets of heat and distribute the heat evenly. Pockets of heat can burn your child’s sensitive mouth, so you can ensure that the heat is more evenly distributed by placing the heated milk into a baby bottle or sippy cup and shaking the milk well.
Heating Plant-Based Milk in the Microwave
Plant-based milk like almond milk, oat milk, soy milk, potato milk, and coconut milk, is preferred by many over dairy milk. Whether you drink plant-based milk simply because of preference, allergies or lactose intolerances, vegan diet choices, or environmental reasons, there may be a time when you want to heat your plant-based milk.
Depending on the milk base, plant milk may react differently than normal milk to heat. You can heat up plant milk in the microwave using a similar process as heating dairy milk, but you risk milk curdling, thickening, or foaming.
Some plant milk, especially soy milk, can’t handle high temperatures like dairy milk can, so the most you can do is heat the milk to a warm temperature. Heating at high temperatures can also destroy the immunological components found in the milk that have anti-infective properties.
Overheating can also cause the milk to lose protein, antioxidants, and fats found naturally in the milk, so you will want to only heat it to a warm temperature. With all plant milk, you’ll need to heat it gradually at a low or medium heat to avoid overheating the milk or causing any foaming or coagulating.
Heating plant-based milk can help enhance the natural flavors and even make for a more enjoyable drink. For a general plant-based milk microwave heating process, follow the steps below, modifying slightly according to the type of milk as listed below the step-by-step process:
- Pour milk from the carton into a microwave-safe container or glass
- Cover the container with a folded square of a paper towel and place it in the center of the microwave turn plate
- Set the microwave to low or medium heat, enter a 15-second time interval, and press start.
- Remove container from microwave, stir milk, and replace the milk back into the microwave
- Heat for another 15-second time interval
- Remove container from microwave and stir
- Repeat steps 5 and 6 until the milk has reached the desired temperature, being sure that the milk doesn’t exceed 110℉, which is generally the heat tolerance for most plant milk. You can check the temperature using a cooking thermometer to ensure the milk doesn’t overheat.
- Soy milk – heat slowly and gradually at medium heat
- Almond milk – heat at low-medium heat for no longer than 2 minutes
- Oat milk – start by heating for 2 minutes, then at 15-second intervals, stirring between each interval
- Rice milk – heat at low-medium heat setting for 15-second intervals, stirring frequently
- Coconut milk – before heating, shake well. Heat at medium heat, stirring the liquid frequently using a wire whisk or fork. Milk is heated when it begins to steam.
Microwaving Breast Milk
Pre-pumped breast milk for babies is often refrigerated or frozen for preservation, but it must be heated up to restore its natural warmth and consistency. Many women will heat up their breast milk over the stove, as this is recommended for more consistent heat distribution and for the preservation of nutrients, but in a pinch, breast milk can be heated in the microwave if done carefully.
We don’t recommend heating breast milk in the microwave unless absolutely necessary. You won’t want to do this frequently, as the microwave can cause the human milk to lose fat content, immunological components, anti-infective properties, and bioactive proteins, so microwaved milk will only so much fill your baby’s stomach.
Microwaves also don’t distribute heat very heavenly into food or liquids, so be sure to stir the breast milk at frequent intervals during the heating process to avoid any pockets of heat burning your baby’s mouth or tongue. You should also be sure to let the milk sit for a few minutes to decrease from a high temperature to a warm temperature before feeding it to your baby.
Follow the similar processes of heating dairy or plant milk described above, stirring at 15-second intervals and heating at low-medium heat. You may only need to heat the milk for one or two 15-second intervals, as the milk only needs to be lukewarm.
Alternatively, the best way to warm breast milk is by running the bottle under cool water, gradually adding warm water, or by placing the bottle into a pot of pre-warmed water after it has been removed from the heat source. Once warmed, shake the bottle to evenly distribute the heat and mix all the fat particles into the milk. Test the milk on your hand to ensure the milk is lukewarm before feeding it to your baby.