Assuming we can give away unused food so waste is not the issue: what are the realistic savings? What are values from the past?
And can't we just work on honor? You pay, you eat. We trust DDs with more than that...
Can the hostel really only plan a month in advance? This luxury is unusual, normally they will have more volatile bookings.
Can we not order X portions and see how many those feed? German portions are large. And Vaumarcus had backup food when planning was wrong. Just whip up noodles or bread and cheese.
This all feels complicated...
Sent by mobile; excuse my brevity.