If you don’t have access to a stove or just don’t want to turn it on because it will heat up the entire kitchen, you can still boil milk. Simply turn to your trusty microwave oven. Just as you can warm or scald milk in a microwave, you can also boil it. You’ll have to watch it carefully and pay attention to the cooking temperature.
To begin, you’ll need a microwave-safe container. No metal, obviously. But glass, ceramic, and microwave-safe plastic bowls are all fine. A pouring cup or jug — think Pyrex measuring cups — is ideal. Pour the desired amount of milk into the container and place it in the center of your microwave.
Next, select your cooking temperature. Never heat milk at full power or high power. It will heat up too quickly and it might scorch or curdle. Instead, heat your milk at 50%-60% power (or medium power if your microwave doesn’t have percent settings).
Ideally, you should heat the milk in 15-second increments, stirring every time you reset the timer, because microwaves heat food unevenly. Stirring prevents a film from forming on the milk’s surface and distributes the heat so that all the milk will boil at the same time. Not stirring is one of the most common mistakes people make when cooking with milk. It takes about 2½ minutes for a cup of milk to boil in a 700-watt microwave.
Avoid problems when boiling milk in the microwave
Another useful tool for heating milk is an an instant-read thermometer to check the milk’s temperature so you don’t overheat it and risk scorching or curdling. Milk boils at 212 degrees Fahrenheit, the same as water.
If your milk looks like it’s starting to form lumps (curds), a film appears on the surface, or you smell a burnt odor, you have heated it too quickly. Stop microwaving the milk right away. If the milk is scorched, you’ll have to discard it, as it won’t taste good.
Another problem you might encounter is having your milk boil over. To avoid this messy situation, don’t overfill your container. Leave room at the top for the hot milk to expand. You could also rub some cooking oil or butter around the top edge to stop boilover. Another solution is to lay a wooden spoon, wooden skewer, or toothpick across the top of your container, depending on its size. This will help break up the big puff of bubbles that can form when you are boiling milk in the microwave. And don’t forget to use a potholder or oven-safe glove when retreiving your container as it will be hot.
