Boiling raw milk kills microbes and makes it safe to drink. It is safe to drink pasteurized milk cold, but boiling it can prolong its shelf life. If you just need to heat the milk to cook or drink it warm, it's easier and faster not to let it boil.
Method 1 of 3: Boiling Milk on Stove
Step 1. Check whether the milk needs to be boiled or not
Some brands are safe to take without boiling. Follow this guide when deciding whether to boil milk:
- Raw milk should be boiled whenever possible.
- Pasteurized milk should be boiled if stored at room temperature. It does not need to boil if stored in the refrigerator or in a very cold environment.
- Boxes sealed with "UHT" on the label are safe to take, even at room temperature. UHT stands for "ultra high temperature", a type of processing that kills all harmful microbes.
Step 2. Place the milk in a large, clean pot
Choose a pot that is taller than necessary to allow space. Milk rises when it boils and it is very common for it to overflow from a small pot.
- Thoroughly clean the pan, or residues may curdle your milk. If this becomes a problem, choose a pot to use just for milk.
- Copper, aluminum and stainless steel heat up much faster than iron and other heavy materials. This saves time, but also requires extra attention to avoid burns and spills.
Step 3. Heat the milk until it starts to bubble
Heat the milk over medium heat and give it your full attention. A glossy layer of cream will rise to the surface as it heats up. Soon small bubbles will rise from under the cream, starting at the outer edges. When this happens, put it on low heat.
You can heat the milk over a high heat to save time, but take care of it at all times and get ready to lower the heat. Over high heat, the milk will quickly go from the first bubbles to the overflowing froth
Step 4. Stir occasionally
If your pan does not heat evenly, the milk may burn in some parts. Stir occasionally with a wooden spoon or heat proof spatula, scraping the bottom of the pan.
Step 5. Dismantle the foam as it forms
The cream on top of the milk holds steam as the milk boils. The steam turns the cream into foam, which rises quickly and overflows. React quickly to avoid:
- Lower the heat until the milk bubbles evenly.
- Stir constantly to break the foam.
- Leave the spoon or spatula in the pan (optional) This breaks the cream off the surface, creating a space for the steam to escape. Just be careful to use an utensil that can withstand prolonged heat without melting.
Step 6. Boil for two or three minutes, stirring constantly
It's enough to make your milk safe to drink. Boiling more than that will start to destroy the nutrients.
Step 7. Save immediately
Put the milk in a closed container right away. Store in the refrigerator, or in the coldest area of your home. If refrigerated, it does not need to be boiled again. If you are going to store milk at room temperature, it may need to be boiled again before each use.
Boiling too often destroys nutrients. If you don't have a fridge, try to buy only as much milk as you need to consume once
Method 2 of 3: Boiling Milk in the Microwave
Step 1. Do not rely on this technique to make raw milk safe for consumption
Microwaves boil the milk for a short time before it overflows. You can still kill some microbes, but not enough to treat raw milk or milk stored at room temperature. These must always be heated on the stove.
Step 2. Put the milk in a clean mug
Avoid mugs with metallic paints, which are not microwave safe.
Step 3. Place a wooden accessory inside the mug
Put a wooden spoon or chopstick in the mug. Use an accessory long enough not to fall into the mug. This way the steam escapes through the cable instead of causing a foam explosion.
Step 4. Heat for 20 seconds at a time
Between one heat and another, remove the mug and mix for five to ten seconds. This precautionary method minimizes the risk of spillage.
Method 3 of 3: Blanching the milk
Step 1. Blanch milk for some recipes
Blanching, or heating until almost boiling, changes the behavior of milk in bread recipes. Some people like to scald pasteurized milk as an extra precaution against microbes, but it's not necessary if it was stored in the fridge.
If the milk has not been pasteurized or has been stored at room temperature, boil it
Step 2. Put the milk in a clean pot
A thick-bottomed pan heats the milk more evenly, decreasing the chance of burning.
Impurities can spoil the milk, so clean the pot thoroughly
Step 3. Heat over medium heat
Never use a high heat as this increases the chances of the milk burning or overflowing.
Step 4. Stir occasionally
Keep an eye on the milk and stir every minute or so. A wide spatula works well so you can scrape the bottom of the pan if the milk starts to stick.
Step 5. Watch for bubbles and vapors
Milk is considered "poached" once it has a thin layer of foam on top. Small bubbles will appear on the edges of the pan and very slight steam will come out of the surface.
If you have an infrared thermometer, check that the milk temperature has reached 82°C
Step 6. Continue heating for about 15 seconds
Stir constantly to prevent it from overflowing.
Step 7. Save the leftover milk
If milk is left over after drinking or cooking, store it in an airtight container in the refrigerator. If this is not possible, store the container in a cool place. At warmer temperatures, which are prone to bacteria, milk is only good for a maximum of four hours.
- If you want to add spices or sugar, do so after boiling and turning off the heat.
- You can buy a metal diffuser to place between the stove and the pot. With it, the bottom heats up more evenly, preventing the milk from burning. However, it takes much longer to heat up than in an ordinary pot.
- You can remove the cream from the surface when the milk starts to boil. Keep it for use in pasta sauces or vegetable stews with meat.
- Acidic foods can curdle milk. This includes ginger and some other spices.
- Be sure to take care of the milk in the pot. Milk starts boiling much faster than water.
- Hold the pan with a cloth, thermal gloves or kitchen tongs. Do not leave the pan unattended, especially if there are children or animals in the room.