I had so many apples this year that I bought a cider making kit and have a gallon percolating away in the bathtub. Thinking ahead, it seems like having to buy more brewing yeast every year is not very sustainable in case of a shortage. I make yogurt and sourdough bread using leftovers from the previous batch. Has anyone tried doing something similar with leftovers of last year's batch of apple cider or wine instead of buying brewing yeast?