Open source managers for my recipe collection, maybe yours too?

My dream recipe database would link to USDA’s National Nutrient Database for Standard Reference by using that database’s NDB_NO field as the primary key for recipe ingredents. This would allow rapid calculation of at least approximate macronutrient profiles of each prepared recipe. As an added bonus, I’d like to create a table that maps barcodes (UPC, EAN, etc.) to NDB numbers. Next step after that is to incorporate barcodes into my personal bookkeeping (perhaps by adding a BARCODE column to GnuCash’s SPLITS (as in “transaction splits”) table so materials cost of each recipe is at my fingertips, based on data collected empirically out in the actual market economy.

I’ve made a number of (mostly false) starts on this project. The main discouraging factor is that making it information-rich enough to be entertaining would entail millions of keystrokes worth of data entry. Getting some number of other people interested may cause network effects to kick in, but seems unlikely. Surely if it were feasible someone would have done it by now…