What are the reason behind wearing a chef hat?

Those tall Chef's hats are often an indication of who is the chef. It's like a military officer's hat. But not all chefs wear white hats. You'll see everything from skull caps to Baseball caps in the kitchen. The idea is to confine hair to avoid it's dropping into food. Hats also look a lot less dopey than hair nets, which are used for the same reason. (Think of the lunch ladies at your elementary school!)

White hats, however, are traditional. I suspect it's because, in part, that white implies cleanliness and sanitation. Aprons are often, and traditionally, white too.

White shows dirt, stains and spills readily. It's a good indicator of when it's time to change to clean garb.

FriPilot