I've just started to try and grow yeast from left over liquid vials from my last batch. Right now I've got a jar of WL1 and WL530 that seem to be doing well and reproducing. How long do I need to leave them in the jar before I should drain off the wort and start a new batch to produce more yeast? I figured they would eventually need a new solution in order to keep reproducing or will they continue to reproduce in the same solution? I found this picture on the site that is very close to what I have. I started out with only a very thin layer at the bottom and it is currently the same as the picture below. My other question would be is this enough to pitch in a 1 gallon batch or a 5 gallon? I'm currently only doing 1 gallon test batches until I get something I really like and then will step up to 5 and would like to have enough yeast to use in a 5 gallon batch?