Why do you always have to use a metal spoon to fold in egg whites?

You don’t. I’m a certified pastry chef and I use a spatula. My chef instructor used a spatula. Every other chef I’ve ever personally known has used a spatula. As a matter of fact, I’ve never actually seen a recipe that says you need to use a metal spoon - you must have them all.

I think it means metal, as opposed to a wooden spoon. You don’t have to use a metal spoon, but a wooden one is not always as easy and efficient to use to mix things and bacteria can seep into the wood so you need to wash it really well (especally important with eggs because of the potential salmonella harbouring). Metal spoons are just more preactical. Spatulas are a great alternative though.

Thanx! Cause I get the whole folding it in with a flat object… you don’t want to loose all the air you just beat into those egg whites. But the metal spoon thing I never got… Maybe its just an old fashioned belief, cause these recipes are from my gran’s recipe books.