How to Boil Soy Milk for Greater Health
More and more people enjoy making fresh soy milk at home, believing it’s cleaner and more convenient. However, nutritionist Li Changping from Beijing Hospital warns those who make soy milk at home: proper boiling techniques are essential.
Soybeans are rich in protein but also contain trypsin inhibitor, a substance that inhibits trypsin’s action on proteins, preventing soy protein from being broken down into usable amino acids.
To fully utilize soy protein, one must thoroughly soak, grind, filter, and heat the beans to neutralize the inhibitor’s negative effects. Raw soy milk also contains saponins, which, if not fully cooked, can irritate the gastrointestinal mucosa, causing poisoning symptoms such as nausea, abdominal pain, vomiting, diarrhea, loss of appetite, and fatigue.
So how do you know when soy milk is properly boiled?
When raw soy milk reaches 80°C–90°C, it produces a large amount of white foam—many mistakenly believe it’s fully cooked. However, this is a “false boil” phenomenon; the temperature is insufficient to destroy saponins. The correct method is to continue heating for 3–5 minutes after the false boil appears, until all foam disappears.
Some people boil soy milk repeatedly for safety, but this removes nutrients along with harmful substances. Therefore, boiling soy milk should be just right—timing must be controlled precisely.