So I just harvested yeast for the first time a couple days ago and ended up getting about 3 16 oz mason jars full which is more than I need for sure.... Now I just brewed another batch last night and have one batch to make before I need to make another grain order.... Is this initial yeast harvesting of wyeast 1272 my most viable yeast or can I just keep reharvesting after each batch to keep my yeast up to date?? I know on mr malyy's yeast calculator viability obviously decreases with time so I'm thinking of ditching these initial mason jars of yeast after each of my upcoming primary fermentations to keep my yeast fresh.... Thoughts???
The possibility that something else is growing in your beer (and now mixed in with your yeast) is going to increase with every time that you reuse your yeast. So following that logic the original sample is going to be the cleanest. However it is also going to have a lower percentage of healthy and viable yeast cells. What you could do it use the original samples to make a starter so that you have hopefully both clean and healthy cells. If you feel that your latest beer has no contaminating microbes than it is probably fine to keep re pitching those yeast, as they will be the healthiest. Just make sure that they do not pick up in contaminates along the way.
