What to Know About Boiling Milk

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on February 12, 2024
3 min read

Some people believe that boiling milk is needed to make it safe to use, but what does science say? 

Milk is an important source of vitamin A, vitamin D, thiamin, riboflavin, magnesium, calcium, and several other nutrients necessary for staying healthy and warding off illness. Many of these nutrients are sensitive to heat and could be damaged or destroyed altogether by boiling.

A single cup of milk also contains:

Boiling is not the same as pasteurization, although they’re similar. Pasteurization in the United States involves heating milk up to about 160°F for the purpose of killing bacteria that could make you sick. The boiling point of milk is about 212°F, so it is never actually brought to a boil during the pasteurization process.

If eliminating possible pathogens is your main reason for boiling milk, you should know that the milk you buy in the store is almost always pasteurized, so it has already had these pathogens eliminated. The only exception is raw milk, which, when it is sold, is always clearly labeled as such. Only a few states allow raw milk to be commercially sold, and never across state lines.

Boiling milk is known to significantly lessen milk’s nutritional value. Studies have found that while boiling milk eliminated bacteria from raw milk, it also greatly reduced its whey protein levels.

Other tests have shown lower levels of vitamins and minerals in boiled milk, including vitamin B2, B3, B6, and folic acid -- in some cases by as much as 36%.

While boiling milk drastically reduces milk’s nutritional value, pasteurization does this to a lesser degree. In addition, commercially produced milk is typically fortified with vitamins and minerals to replace those few that may be lost in the heating process. 

The reason for pasteurization is to protect against possible contamination in raw milk. Milk production is a complicated process, with contamination possible at many points along the way.  The size of the farm, time of year, cleaning practices, and health of the cows are just a few of the many factors that can introduce potentially dangerous bacteria like listeria into raw milk.

Boiling milk can be a smart thing to do if, for whatever reason, the milk you’re buying is unpasteurized. Many countries, and some states, do regularly sell unpasteurized milk. Bringing unpasteurized milk to a boil will make it less nutritious, but it can also kill the bacteria that could make you seriously ill, so the tradeoff is probably worth it.

Many infants and young children live with cow’s milk allergy (CMA), which is caused by a negative reaction to milk protein. It’s one of the most common forms of childhood food allergy and can have a serious impact on a child’s health and development. 

Boiling milk has a strong effect on milk’s protein composition. It changes many of the proteins that contribute to CMA. That may not be enough to make a difference for some, but if you or your child have a milk allergy, check with your doctor to see if boiling milk might help.