I have recently started a “yeast jar”. I put three tablespoons of flour and two tablespoons of water in a jar. I made sure that the jar was not closed all of the way so that air can get in. Every 12 hours I stir it. Every night, I “feed it” three tablespoons of flour and two tablespoons of water and stir it. It has been about 5 days. It now smells “yeasty” and has bubbles in it. I put it in the fridge. From now on, I will “feed it” weekly and it will stay in the fridge. This is a cheap alternative to commercial yeasts. I want to get into making my own bread and other baked goods and this “yeast starter” will be a part of that. I have already made some things using “self rising” flour, but it still not as good IMHO as using real yeast.