We expense any food bought for the crews. This includes when/if I buy coffees, lunches, etc. We also have a kitchen at the shop, so all the food there is expensed too. My understanding from our accountant is that for our company set up (LLC) which is like a partnership, the food for workers is a 100% expense. Food for partners/owners is 50% deductible. We keep all receipts, especially for cash disbursements. This way its provable, and also, when entered into Quickbooks for instance you can see exactly how much was spent.
When we were building our shop, with no facility and only had a refrigerator and shelf in an office trailer for food, we kept track of all the coffee stops. At that time, my wife would often make us picnic lunches, and bring them in at lunch time. Nonetheless, we spent thousands at Dunkin Donuts, and you wouldn't believe it except when it all got tallied up at the end of the year. When the building was finished, I plumbed in a commercial coffee maker into the kitchen, and one into the shop. This cut the D&D budget way down. Now I don't really buy coffee to go at all anymore. But everytime the company buys lunch, I add the receipt.