Yeast suspension - how?

[TStarr]

Hello all - new here but hope someone can answer a couple of perplexing questions - first one is how to 'Suspend Yeast' so that I can reactivate at a later date, rather than throw away and start again. Do I dry it - bone dry, or damp, or leave in solution? Then keep in fridge or freezer? and how long can it be kept? Does it still work as well later on, or pick up any funny flavours? What should it be kept in - bottle/plastic bag/cling film/or what? I thank u in anticipation.

[MKG]

I know of no way that this can be achieved successfully at home, but that doesn't mean that it's not possible. However, if you're going to store yeast for an appreciable time, then it has to be inactive - and how can you achieve that safely? Drying may work, but not if you're drying the dregs from the bottom of a demijohn. That will contain a huge proportion of impurities which would probably continue to deteriorate even if dried. So you'd have to do a "clean" culture starting from dried yeast - in which case why not simply keep it in its original dried form? Fresh baker's yeast, though, survives the freezer (at least for a while) so you may get some mileage from freezing some of the lees from winemaking. I simply don't know.

On the other hand, you can treat your yeast in a similar manner to a ginger beer plant. Start a yeast colony (a pint of tepid water, a squeeze of lemon juice, a tablespoon of sugar, a couple of pinches of yeast nutrient and some yeast) and keep it in a bottle plugged with cotton wool. Over the course of a month or so, feed it a teaspoon of sugar every few days. When you want to make some wine, use half the contents of the bottle instead of dried yeast, then make up a new batch using three of four tablespoons of the remaining liquid. If you're careful, you won't need ever to buy yeast again - although it would be better for several reasons to totally renew the colony every six months to a year.

Mike