Frozen yeast bank with yeast cakes?

I red FlyGuy's thread on starting your own yeast bank and I am very interested. I have already started looking for the equipment I need, and I was wondering. Would it be possible to clean a yeast cake and then reuse that to fermenter a starter, once it's done fermenting shove it in the fridge so that the yeast falls out and extract that yeast to freeze it?

Are there other (better) ways of doing this?

The main reason I ask is because I have some Apfelwein currently in the final stages of fermentation and would like to use that yeast as my first test batch at freezing yeast. I'm using Lalvin EC-1118 and I figure if I don't succed, it will be a good learning experience and a new pack of that yeast is a dollar. I may go and buy a quart of apple juice to use as the starter so that I'm not adding weird flavors to the yeast.

mrfocus said:

I red FlyGuy's thread on starting your own yeast bank and I am very interested. I have already started looking for the equipment I need, and I was wondering. Would it be possible to clean a yeast cake and then reuse that to fermenter a starter, once it's done fermenting shove it in the fridge so that the yeast falls out and extract that yeast to freeze it?

Click to expand...

Yes, that's called washing yeast, and it's what I do while I wait to save for yeast bank equipment.

I have read Bernie Brewer's thread on washing yeast (that's why I said I knew yeast could be washed) but he has full jars of yeast which he uses to pitch. I would want to go further, concentrate the yeast even more and then put a bit of that concentrated yeast into vials and freeze them. Thus I can keep them for much longer than when refrigerating, with a smaller risk of having dead yeast.

The other problem is that I don't have a beer fridge, so if I were to just do washing, it wouldn't take very long before I was monopolizing a whole rack in the fridge.

It might be more work to freeze dry yeast that is so cheap. I've started to freeze my own yeast from liquid strains, I've done it from both slurries and starters, just remember that you need to add glycerol/glycerin and if you don't have a non-defrost cycle freezer, you need to have a way to make sure the yeast doesn't thaw in the defrost cycle.

I also read that great thread on yeast banking, and went ahead and purchased the equipment. It was MUCH cheaper to buy the glassware in bulk, so I purchased multiple sets and am selling off the rest of the kits.

I got:

10ml graduated pipettes and valved filler bulbs
1000ml erlenmeyer flasks
600ml beakers
autoclavable foam plugs
16ml vials (12 per "kit")

Anyway, I have frozen 4 vials each of 2 yeasts, one was straight from a primary fermentation yeast cake (didn't wash). I plan on doing a test starter from each of them to evaluate the technique (I modified the procedures a bit, we'll see...). I'll post the results.

I could see that if the yeast was very "used up", that is, sat under fully fermented beer for a while and had low internal energy stores, it might not hibernate well. I don't know enough about yeast to say, so we'll have to wait for the results of the experiment!

Professor Frink said:

It might be more work to freeze dry yeast that is so cheap.

Click to expand...

Yeah, probably, but this is just testing. I will most likely freeze it for a week, take it out and try and ferment another starter just to test the viability of it.

So I'm still wondering how I could effectively concentrate the already used yeast. I mean, someone must have already tried freezing a second generation?

Thanks,

mrfocus

Thanks for sharing.