Eli5: Why does peanut butter get thicker before it gets thinner when you add a liquid to it?

Question

(same with tahini)

In: 1

Answer 1

I’m not sold on the top comment emulsification explanation, especially if you’re using single ingredient PB. I don’t believe there are any emulsifiers in single ingredient PB, but adding either water or soy is going to change the polarity of the mixture, causing the hydrophobic proteins to change their shape (conformation). By inducing the more polar portions of the proteins to be exposed, you increase the bonds between them (proteins are VERY sticky), and the mixture appears to get thicker.