When I mix whey protein powder into warm porridge (that I cooked in the microwave), the thick porridge becomes much less thick.
I searched this, and I found several forum threads discussing this too so it seems to be a common phenomenon. Happens when cooking porridge on the hob too, not just from mixing protein in after cooking.
I make the porridge through simply heating porridge oats + cow's milk. It doesn't matter if the oats are steel-cut or rolled, part of a fast-cook microwave pack, or completely natural.
How come the porridge becomes more liquidy when whey is stirred into it?