How do I save and store yeast?

[Duxuk]

I'm brewing (and drinking ) regularly now. Each time I have bought a new sachet of English ale yeast which seems an uneccessary expense.
I've searched the forum a little to try to find a definitive guide to how to keep some yeast from my last brew for later use.
My current brew has been fermenting happily for a week as of today. I know I shouldn't be touching it but it tastes great already!
How should I save yeast from the FV? I am hoping that I can get a 500ml PET bottle full. SWMBO would just about tolerate that in the fridge, if I assured her I was saving money.

Andrew.

 

[Muddydisco]

Have you looked at these for a starting point?

http://www.thehomebrewforum.co.uk/viewtopic.php?f=30&t=4406

http://www.thehomebrewforum.co.uk/viewtopic.php?f=30&t=180

 

[graysalchemy]

There is plenty of threads on here about washing the yeast separating it from the trub etc. Yeast has a shelf life in my experience of a couple of months in a sterilized closed container in the fridge after that it usually gets infected. However what I do now is transfere the trub to a sterilized 2L PET topped up with some of the beer. I find that it tends to pressurize the bottle slightly enough to give a protective layer of co2. Once it sttles you are left with about half beer and half yeast trub etc. I have had one in the fridge from last october and it is fine. The only problem is that they can be messy to get out if they have carbonated a lot.

I used a 2L yeast slurry stored in this way on my barley wine. It fermented exceedingly well and quite fast considering it was a 1080+ beer.

 

[Duxuk]

Thanks for the replies, I'll definitely be giving it a go with my current beer.
One other point though. Am I safe to use the method for brew after brew or is there too much danger of infections building up?

 

[Muddydisco]

Depends if your using a starter method, that way if you keep reusing and the yeast goes off etc you loose the starter not the whole batch of beer.

If your not doing a starter I would say 3-4 brews max depending on how often you brew.

Also found another good guide that I couln't find first time around in my bookmarks

Clicky

 

[graysalchemy]

There will always be the risk of infection put no difference from brew to brew. The only thing I say is if you have a beer which goes off ditch the yeast.

 

[artiums_enteri]

Actually after the 4th pitch of the same strain it is recommend to start a new pitch. By the 4th washing you have collected the most flocculant of yeast and pitched them 4 times. The yeast get to the point that once they flocculate they can't bud anymore, and now you have a strain that won't attenuate.


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[graysalchemy]

But if you are pitching slurry and not washing surely you won't have this problem. Isn't that what commercial breweries do, I am sure I read about one which re used the yeast 100+ times.

 

[Duxuk]

That's got me thinking :hmm: . When the current brew goes in the barrel, why don't I have everything ready to start a new beer which will be bottled?
So do I honestly just not wash the FV? How much of the slurry should I leave in the bottom?

 

[graysalchemy]

No your FV will no longer be sterile especially around the top where all the crud has been exposed to the air. Put the yeast cake in a sterilalized container and start again. Better be safe than sorry.

 

[artiums_enteri]

While you certainly can pitch on top of a yeast slurry, it's not really the best practice. When commercial breweries pitch "on a slurry" they actually remove the top and bottom portions of the yeast cake and use only the center where the viable cells are. Most commercial breweries have gotten away from it completely, washing yeast and pitching it more than five times.

The yeast slurry has a huge amount of dead cells, as well as the flavor remnants from the previous beer. If you made an IPA and then pitched an American blonde and pitched the wort right on top of that yeast used for an IPA you would get a lot of characters in that blonde you weren't shooting for. The cell walls of the yeast absorb and store the alpha acids of the hops. It's recommended to wash the yeast prior to pitching.


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