Re-using yeast - How long is it viable
- Thread starter Matteo57
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benbradford
Well-Known Member
6 months or 6 generations is the general concensus, but I imagine everyone uses it longer if necesary... I just dumped some yeast from a year ago though... didn't seem like it was necesary to keep it.
Until it makes a bad batch
look up washing yeast!! and the reason i do it is to save money.
Bradinator
Well-Known Member
I recommend searching yeast washing, a handy technique to harvest and reuse yeast from previous batches.
1 month is no problem.
3 months generally is no problem.
Longer than 3 months it starts to become a matter of how good your sanitation was. You don't want bacteria to become dominant.
...... I have no problems using washed yeast that is a year old.
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Matteo57
Well-Known Member
Is there a certain sized container you want to try to stay at or larger or does it really matter if you put it in a large enough starter? Like baby food jars work? or do you want something larger or does it matter much? Thanks for all of the replies!
JimTheHick
Well-Known Member
Baby food is too small unless it's chock Full of yeast or you plan to make a starter. After hearing everyone rave on starters I've been saving jars (like 10-16 oz) with a nice clean layer of washed fluffy white yeast (about 1/4 to 1/2 inch once it all compacts). Wrap in foil. They like the dark.
I did a big 9% stout and the yeast I washed after 4 weeks of primary were the only to start off really sluggish even after a starter.
I did a big 9% stout and the yeast I washed after 4 weeks of primary were the only to start off really sluggish even after a starter.
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Matteo57
Well-Known Member
How did it turn out after it finally started? Still good? What is a good size of a starter to do on washed yeast?
bottlebomber
Well-Known Member
I just re-used kolsch yeast that was almost a year old... it took an extra day to start chugging, but when it did there were no problems
bottlebomber
Well-Known Member
insurgus said:
I hate it when people do this... I think it might even be against forum policy. Who the hell is supposed to know what this means?
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Matteo57
Well-Known Member
means quoted for the truth.... thanks Google
JimTheHick
Well-Known Member
Matteo57 said:
Took 65 hours to start, but then got a nice krausen and vigorous ferm. It's only been 7 days. Fingers crossed. Will take gravity soon but everything seemed good except for the delay.
This starter was 1.5 qt. it was probably an 1/8 cup of yeast once washed. Probably should have stepped it up......
Check the sticky at the top of this subforum titled "Washing Yeast Illustrated". It's very informative and I've followed it multiple times with success.
I've used 8mo old yeast with success before and I imagine I could use older yeast, just haven't tried so yet.
I just did two different beers with some s-04 and s-05 that had been washed and stored for 11 months. I have some year old notty on the stir plate right now to see if it survived. As was said your sanitation has to be spot on. I have used snapple bottles but had a batch go rancid in those. Now I just use beer bottles and cap em. I don't know if it matters but I run em over and cap em with zero head space. It seems to be working so far.
ChickenHops
Well-Known Member
I wash and use yeast all the time. Actually if I'm not mistaken it's rinsing yeast since I don't use an acid solution. I just use sanitized water. I store the yeast in canning jars, just like the aforementioned sticky on washing shows.
I've pitched yeast that I've rinsed 6 weeks prior and had great results. Usually if the rinsed yeast is older than 3 weeks I'll make a starter from it. (Age based on rinse date. It may have been sleeping in the primary for several weeks prior to that.)
BTW, when I first started rinsing yeast I worried about infections. I made streak plates from the trub of a half dozen different batches. Only healthy yeast grew on the plates. I suppose it depends on sanitation, and perhaps luck. I've never had an infection from using yeast rinsed from a cake. I worry more about petite mutants more than infections now.
One thing I've noticed is that subsequent generations of yeast can act differently. For instance, I recently re-pitched some WLP002. The second batches didn't look like the first. Yeast in the original batch looked like curdled milk when roused. The next batches (two so far) didn't have that look. They still cleared nicely. They attentuated better, too, although that could be from other factors.
I've pitched yeast that I've rinsed 6 weeks prior and had great results. Usually if the rinsed yeast is older than 3 weeks I'll make a starter from it. (Age based on rinse date. It may have been sleeping in the primary for several weeks prior to that.)
BTW, when I first started rinsing yeast I worried about infections. I made streak plates from the trub of a half dozen different batches. Only healthy yeast grew on the plates. I suppose it depends on sanitation, and perhaps luck. I've never had an infection from using yeast rinsed from a cake. I worry more about petite mutants more than infections now.
One thing I've noticed is that subsequent generations of yeast can act differently. For instance, I recently re-pitched some WLP002. The second batches didn't look like the first. Yeast in the original batch looked like curdled milk when roused. The next batches (two so far) didn't have that look. They still cleared nicely. They attentuated better, too, although that could be from other factors.
I've also used year-old washed yeast. I did double up on the amount, though (used two instead of one). I made a 1L starter on the stirplate and it had krausen after 24 hours (which surprised the heck out of me since it was on a stir plate).
I pitched it and it took off within a few hours, just like normal. I measured the attenuation of this batch versus the original batch I used it in a year ago and it was spot on at 70%. Granted the beers were different, but they were close enough for me to call it even.
I pitched it and it took off within a few hours, just like normal. I measured the attenuation of this batch versus the original batch I used it in a year ago and it was spot on at 70%. Granted the beers were different, but they were close enough for me to call it even.
ChickenHops
Well-Known Member
I acquired some lab equipment last winter when I began slanting yeast. I found a good used microscope and went from there. I discovered that yeast are more viable than I expected. A lot depends on how they're handled.
Like any living thing I suppose if they're given a good environment they'll thrive. If they're stressed then all bets are off.
Healthy yeast stored properly will stay viable for quite some time. The viability of older yeast can sometimes catch you by surprise. I obviously didn't leave enough head space in this starter.
Like any living thing I suppose if they're given a good environment they'll thrive. If they're stressed then all bets are off.
Healthy yeast stored properly will stay viable for quite some time. The viability of older yeast can sometimes catch you by surprise. I obviously didn't leave enough head space in this starter.
