What is the white foam on top of Quaker Oats cereal when you add boiling water?

The white foam that appears on top of Quaker Oats cereal when you add boiling water is primarily protein foam.

Here's why:

* Oat protein: Oats contain a significant amount of protein. When you add boiling water, the proteins in the oats denature and unfold. This unfolding process creates air bubbles that get trapped within the protein structure, leading to the formation of foam.

* Starch: Oats also contain starch, which gelatinizes (thickens) when heated. This gelatinization process contributes to the overall thickness and texture of the oatmeal, further trapping the air bubbles and increasing the foaminess.

* Other factors: Factors like the amount of water added, the type of oats used (rolled, steel-cut, etc.), and the length of cooking time can also influence the amount of foam produced.

The foam itself is generally harmless and does not affect the taste or nutritional value of the oatmeal. In fact, some people enjoy the fluffy texture it provides.

However, if you find the foam excessive, you can try reducing the amount of water you use or stirring more vigorously to help release the trapped air bubbles.