why can’t you mix old and new flour?

Question

I just read somewhere that you shouldn’t mix old and new flour, but can’t find any websites that explain why you shouldn’t do this. Does anybody know?

In: 42

Answer 1

First expired first out

Mixing old flour with new means you still have old flour. If the next person does it too (say you’re working commercial and everyone has a habit of topping off the old stuff into the new), you will have an infinitely old mixture of dangerous food pathogens.