Harvesting and reusing yeast from starters

If you search on here you will find some yeast bank stuff from LOR

The other thing you can do is to build up your yeast from individual colonies. It's not nearly as hard as it sounds at first. You make up some plates using agar mixed with some nutrient -- honey might work but I typically use beer wort. Then you streak the plates taking the yeast from anything that still has live yeast in it -- finished mead, beer, something actively fermenting, a way out of date tube of liquid yeast, whatever. Let this grow for several days until you see many many individual colonies developing. Take 10 colonies that are not touching their neighbors and that look healthy (i.e. don't take one that looks different from the vast majority) and add them to 10-25ml of wort/must. You want this to have sufficient nutrients, so I'd use must that has fermaid O or boiled yeast in it if using must, and it should be weak, with an SG of 1.020 or so. Let the yeast grow for 24-48 hours and then bump up the volume by a factor of 10, i.e. to 100-250ml. This can have an SG of 1.040 or so. Keep bumping up the volume by a factor of no more than 10 with your wort/must having an SG of around 1.040 until you have enough yeast to pitch. The book "Yeast" by White and Zainasheff gives you the much more detailed version of how to grow your own yeast as well as how to store yeast for later use. If you're interested in doing that I highly recommend the book.

By all accounts, it's doable/feasible, but after about 3 or 4 generations the yeast does mutate......

Here's what I used to do when I was experimenting a lot, so using the same yeast in many batches. However, currently I'm not making as much and keep wanting to use different yeasts, so for me not worth it.

I'd take my yeast, make a one gallon starter, wash it, divide it into 4ths seal them in the mason jars much as was earlier described, Then I would use three of them and use the fourth for another starter.

This way not only did I get many more batches per generation, but I went 5 generations before I started noticing an unacceptable change in the flavor. That made for a lot of mead from one package of yeast.


Cheers
Jay