Is it possible to patent my own logic for determining if pantry items have gone bad in a software system for managing items?
I don't expect there to be a god-given algorithm for this logic, but if I have my own, can I patent it?
A quick google search for warehouse management systems with logic for tracking expiration dates brought back this system. While it's not a pantry system and is in fact intended for much larger operations, it does track products and locations, includes "Tracking for Expiration Dated Food", and is mobile. I've never used it so I can't attest to the truth in the advertising.
Relevant search terms in this case would be 'warehouse management' or 'asset management' software.
I don't have the ability to look up if there's a specific patent on the subject currently.
These patents and applications seem to cover what you're looking for:
The first one consists of web-based software plus an in-house terminal; the second is an RFID system; the third is "virtual" on an "electronic device". Of them I think the first is the best fit (and kind of cool.)
Without specifics, it's hard to give an absolute answer. For instance, "A System for Tracking Expiration and Stock of Pantry Items" would likely have quite a bit of prior art (and perhaps a degree of obviousness). However, if there's something unique about the process that you can describe, it may be patentable.
A specific, applied method like that you describe is, in principle, patentable under section 101. The real question is whether it meets the other standards for patentability, as other answers have noted. Is is truly novel and nonobvious? Can you describe it an an application-specific way? If the answers to this are yes, then you have a shot.