Recipe-from-ingredients tool?

Is there an online tool out there that allows you to list what ingredients you have on hand, and then shows you a list of recipes that you can make with it? Or at least what you're close to?

If not, would there be interest in me developing one?

There is! It's called homebrewtalk.com. Just type up a list of your ingredients, ask the magical forum nerds what you can brew and they'll come up with an answer for you! It's all manual, no automation, so it might take a while sometimes.

Seriously though, I don't think I've seen anything like that. There is a lot of overlap on recipes and a lot of it is open to interpretation by the individual brewer so that might be hard to do.

It wouldn't be too terribly difficult. Obviously it would be based, mostly, on getting enough recipes in it to be useful.

If i could get my hands on a big pile of beerxml files, I could, fairly easily, make up a proof-of-concept for feedback.

I would like to see this happen!

Consider this: anyone who has extra ingredients on hand probably already makes his own recipes. Kits don't come with extra ingredients (except dextrose). The only other sources of extra ingredients would be gifts and from making beers from recipes someone else has written.

This demographic doesn't seem very large. Among this group, you have people who are good at working leftovers into recipes.

I don't think you should count on this being useful to a whole lot of people.