Whatever works for raising fruit flies for you is great. the only thing I see missing might be nutrients you can add very easily. Some wheat based baby cereal would add a lot nutrition wise. Adding a little brewers yeast will do the same thing and shouldn't cause diminished production.

Personally I don't like using active yeast because in my cultures the media gets too soupy too fast. This is just my experience though and I know some that swear by it.