I had about a 1/3 full bottle of grape juice that apparently I cross-contaminated with wine yeast. It was bubbling away, so I tasted it. It tasted like a juice fermenting into wine. I had a get-together the night before and there was left-over wine in different bottles. The stuff I would usually just dump out I added to the bubbling juice. Then every time I racked a different wine or mead I added the leftovers to juice bottle that quickly filled. Moved to a gallon jug and just kept adding leftovers from bottling, or transferring or racking into my spittoon of leftover wine. When fermentation was slowing down I added fresh juice, or honey or corn sugar or dried fruit or fresh fruit or anything that had sugar in it.
In 6 weeks I had enough to have filled the gallon jug of mixed wine, mead , fruits, sugars and whatever. I racked it to gallon jug and it tasted great.
This cheap old ba$tard just made a gallon of wine from stuff I would have dumped down a sink or poured on the ground. Can't wait to drink it.