Storing Yeast Slurry in Bags... Would you trust these?

Share your experiences of using brewing yeast.
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Kev888
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Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by Kev888 » Mon Jan 09, 2017 8:23 pm

I'd also be suspicious of how to sterilise the zip part of the bag before opening to get at the slurry. I suppose you could leave it closed and cut the bag open at the other end with sterilised scissors, but all in all jars and bottles seem easier.

Slurry can be convenient and economic if you get enough of it and use it soon. But its relatively low-grade stuff unless you have a conical to be selective, and the convenience is negated IMO if you feel the (dubious) need to rinse or acid wash it. So where a starter is going to be needed and/or where its going to be stored for longer then I'd personally look to other methods.
Kev

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Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by Matt in Birdham » Tue Jan 10, 2017 11:20 am

I'm a total convert to these things having used them for the past 6 months or so. Not for slurry, mind, but for saving overbuilt starter. Typical process now is to make a 1l starter with a new pack of yeast, crash and decant to 200ml then fill 4x these and fridge. Compacted yeast can be measured - after a few weeks should be 5-8Bn per ml if nothing else is in there - and gives you a ballpark figure to work with (approx 50Bn per vial is my guess, from a 1l starter, which both fits the measured yeast and the yeast calculator approximation). Slurry is just too hit and miss for me - little idea of how much yeast is in there, how contaminated etc etc.

McMullan

Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by McMullan » Tue Jan 10, 2017 7:38 pm

f00b4r wrote:
McMullan wrote:Jam jars are better. Don't bother freezing yeast to save money. The correct procedure, equipment and consumables, etc. cost more than fresh yeast. How often are you brewing?
Out of interest any idea of what would happen if slurry was sealed in a bag using a vacuum chamber sealer?
The viability would decline quickly over time, like it does in WL and Wyeast packs. Not being pure yeast in the best condition wouldn't make them comparable to commercially available liquid yeast packs.

McMullan

Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by McMullan » Thu Jan 02, 2020 9:45 pm

McMullan wrote:
Sun Jan 08, 2017 1:56 pm
Freezing yeast successfully requires more than blogosphere lore. Next time I freeze some, I'll document the process to give an idea.
Just managing my YouTube vids and realised I didn't ever post this one. It's still relevant, though, so here it is:


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Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by guypettigrew » Thu Jan 02, 2020 10:35 pm

Wonderful vid, McM, loved it from beginning to end. Must have a go--couldn't possibly cost more than about £10k for the gear!!!

Your vid is a perfect example of "if you're going to do it, do it right'.

Perhaps I'll stay with scooping the yeast from the top of the fermenting beer, storing it in the 'fridge and just reusing it three or four times before buying new.

Excellent music selection as well. No idea what it is, but it adds excitement and fun to the process.

Guy

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Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by McMullan » Thu Jan 02, 2020 11:22 pm

You got it, Guy =D> There's no sense in trying to preserve yeast unless it's done properly. It's easier - and a lot cheaper - to simply buy fresh yeast and repitch a few times or so. That's my point exactly. That's what actually saves the home brewer time and money.

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Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by Kev888 » Mon Jan 06, 2020 12:50 pm

Even the general cleanliness would be a complete pain for me to achieve in my little kitchen, let alone the equipment or procedures!

I must admit that I no longer attempt to keep yeast very long term these days (unless perhaps of a type that cannot easily be bought). A combination of splitting and harvesting can make a vial or slant go so far that the cost per brew becomes pretty negligible really (especially if starter wort is saved from brew days) so I'm not unhappy about buying new - say once or twice a year.

Though it is easier to achieve that kind of value if one can organise brewing to use the same yeast types with reasonable turnover. If they are used infrequently the loss in viability starts to become more of a pain, though within reason not usually a deal-breaker.
Kev

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Re: Storing Yeast Slurry in Bags... Would you trust these?

Post by floydmeddler » Fri Jul 24, 2020 10:55 am

McMullan wrote:
Sun Jan 08, 2017 1:56 pm
Freezing yeast successfully requires more than blogosphere lore. Next time I freeze some, I'll document the process to give an idea.

Storing 'washed' yeast in pure water is blogosphere lore too. At room temperature, mortality becomes detectable after a few weeks. So, at best, it's short term therefore not worth the effort, if done properly.

Slants are easier, if you can maintain yeast health, but you'll have to invest in some basic microbiological equipment (e.g. Bunsen burner, inoculation loop and a decent pressure cooker) as well as consumables. Depending on how often you brew and how many strains you use, this isn't necessarily as economical as simply buying some yeast.

If you are looking for a cheap and effective method that selects sufficiently for healthy yeast, you need to think about carefully harvesting from a fermentation. Slurry is not very sustainable, it's not pure yeast for long. Not all strains top crop well. My advice would be try IPA's method. I've tried it a few times. It works well. Add yeast nutrient at the end of the boil, if you want to help produce healthy yeast to harvest.

http://www.jimsbeerkit.co.uk/forum/view ... 12&t=74852

IPA's method rocks!

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