Do milk solids act as a thickening agent?

Milk solids add slight thickness by boosting body and richness, but they aren’t strong thickeners on their own.

Milk solids can contribute to thickening, but they aren’t classified as a true thickening agent like flour or cornstarch. They add body and viscosity because milk proteins absorb water and swell during heating. This makes the mixture feel richer and slightly thicker, but the effect is subtle compared to dedicated thickeners. 

In products like ice cream and yogurt, milk solids help improve texture, creaminess and stability. They can also reduce iciness in frozen desserts and support emulsification.