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Post by Ken on Jul 5, 2022 13:23:47 GMT -6
Note that all of those talk about oxygen on regard to cell growth. That's not what we were discussing. Maybe it's just semantics. In the first quote it talks about the yeast being depleted if it's harvested and stored and that oxygen is one of the [essential] pieces to getting it back to good health. Or am I reading that wrong?
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Post by denny on Jul 5, 2022 13:30:06 GMT -6
Note that all of those talk about oxygen on regard to cell growth. That's not what we were discussing. Maybe it's just semantics. In the first quote it talks about the yeast being depleted if it's harvested and stored and that oxygen is one of the [essential] pieces to getting it back to good health. Or am I reading that wrong? "many membrane-linked processes do not function optimally. Therefore, the cells only resume growth when appropriate levels of these essential membrane compounds are synthesized (David & Kirsop, 1973), for which oxygen is essential." What they are talking about is that cell growth won't function properly without sterols, which come from the O2. Same thing I was saying.
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Post by tommymorris on Jul 5, 2022 13:56:34 GMT -6
In the first quote it talks about the yeast being depleted if it's harvested and stored and that oxygen is one of the [essential] pieces to getting it back to good health. Or am I reading that wrong? "many membrane-linked processes do not function optimally. Therefore, the cells only resume growth when appropriate levels of these essential membrane compounds are synthesized (David & Kirsop, 1973), for which oxygen is essential." What they are talking about is that cell growth won't function properly without sterols, which come from the O2. Same thing I was saying. One of the things I remember from Mark was you can reuse a slurry a few times and then you want to refresh it by letting growth occur. That’s not what Denny is talking about and it’s not the original question either. But, what I have done recently is build a SNS starter from 2 TBS of slurry if the slurry is older than about 1 month. That renews it and in my case cleans it up (my slurries are nasty with spent hops and trub from the prior batch).
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Post by denny on Jul 5, 2022 14:49:09 GMT -6
"many membrane-linked processes do not function optimally. Therefore, the cells only resume growth when appropriate levels of these essential membrane compounds are synthesized (David & Kirsop, 1973), for which oxygen is essential." What they are talking about is that cell growth won't function properly without sterols, which come from the O2. Same thing I was saying. One of the things I remember from Mark was you can reuse a slurry a few times and then you want to refresh it by letting growth occur. That’s not what Denny is talking about and it’s not the original question either. But, what I have done recently is build a SNS starter from 2 TBS of slurry if the slurry is older than about 1 month. That renews it and in my case cleans it up (my slurries are nasty with spent hops and trub from the prior batch). I do the same thing.
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Post by Ken on Jul 5, 2022 16:05:56 GMT -6
I have been trying to get little-to-no trub into the fermenter and that's usually how it goes. It's also rare for harvested yeast to stick around here unused for over a month. I typically use it relatively quickly and brew back-to-back batches with the same yeast until I think it's time to retire it or I have run out of styles to make with it.
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Post by tommymorris on Jul 5, 2022 16:26:00 GMT -6
I have been trying to get little-to-no trub into the fermenter and that's usually how it goes. It's also rare for harvested yeast to stick around here unused for over a month. I typically use it relatively quickly and brew back-to-back batches with the same yeast until I think it's time to retire it or I have run out of styles to make with it. I usually have two yeasts going at once and only brew every three or four weeks. So, it is easy for mine to get past a month old since I tend to go every other batch with one of the two.
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Post by brewbama on Jul 5, 2022 20:17:05 GMT -6
… I…only brew every three or four weeks. So, it is easy for mine to get past a month old since… . This is why I don’t harvest yeast. I just don’t brew often enough.
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Post by gusso on Aug 20, 2022 18:00:29 GMT -6
Just made a SNS but I'll be keeping an eye on it as the slurry is 4 months old (Belgian yeast). I'm brewing a tripel tomorrow but as a backup, I have some dry Abbaye.
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Post by Ken on Aug 21, 2022 6:41:38 GMT -6
Just made a SNS but I'll be keeping an eye on it as the slurry is 4 months old (Belgian yeast). I'm brewing a tripel tomorrow but as a backup, I have some dry Abbaye. My jury is still out on the SNS starter. I have made two now. They worked. But my stirplate starters worked too. This last one was TWO packs of Omega German Lager 1 with an April date and it took over 48 hours to see any signs of life. I think it comes down to me not really knowing the difference between a stirplate starter and SNS starter, not being able to compare, etc. I'm not a yeast expert and I know that the yeast experts over at AHA have said many times that a stirplate is NOT the way to make a starter. But it always worked well for me and it always worked quickly. In my limited experience, they both work but neither seems to be obviously better.
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Post by tommymorris on Aug 21, 2022 11:06:57 GMT -6
Just made a SNS but I'll be keeping an eye on it as the slurry is 4 months old (Belgian yeast). I'm brewing a tripel tomorrow but as a backup, I have some dry Abbaye. My jury is still out on the SNS starter. I have made two now. They worked. But my stirplate starters worked too. This last one was TWO packs of Omega German Lager 1 with an April date and it took over 48 hours to see any signs of life. I think it comes down to me not really knowing the difference between a stirplate starter and SNS starter, not being able to compare, etc. I'm not a yeast expert and I know that the yeast experts over at AHA have said many times that a stirplate is NOT the way to make a starter. But it always worked well for me and it always worked quickly. In my limited experience, they both work but neither seems to be obviously better. I think I’m reality both methods work fine. The AHA discussion mentioned that stir plates have a shearing effect on the yeast (I have no idea that that means). But, if your method works, I think your fine sticking with it. I like SNS because it’s easy more than any science.
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Post by jimdkc on Aug 21, 2022 12:31:37 GMT -6
Most of the arguments I've heard against stirplates seem to be about 2 specific things: They don't oxygenate very well, and shear stress.
The oxygenation argument seems to be that the typical Erlenmeyer flask used on a stirplate narrows at the top, thus limiting exposure to air at the surface. If you use a large Erlenmeyer flask (4-5 liter) for a 1 quart starter, there is quite a lot of surface area. Also, I never air-locked any of my starters, just capped loosely with aluminum foil.
And regarding shear stress, I think this mainly occurs when the stir bar is spun fast enough to develop a vortex. I never really saw that as necessary. I only ran mine fast enough to keep them moving.
Shaken-not-Stirred seems to be a fine method with minimal additional equipment involvement!
Anyway... My answer to this question is: Dry Yeast!
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Post by Ken on Aug 21, 2022 15:58:49 GMT -6
Most of the arguments I've heard against stirplates seem to be about 2 specific things: They don't oxygenate very well, and shear stress. The oxygenation argument seems to be that the typical Erlenmeyer flask used on a stirplate narrows at the top, thus limiting exposure to air at the surface. If you use a large Erlenmeyer flask (4-5 liter) for a 1 quart starter, there is quite a lot of surface area. Also, I never air-locked any of my starters, just capped loosely with aluminum foil. And regarding shear stress, I think this mainly occurs when the stir bar is spun fast enough to develop a vortex. I never really saw that as necessary. I only ran mine fast enough to keep them moving. Shaken-not-Stirred seems to be a fine method with minimal additional equipment involvement! Anyway... My answer to this question is: Dry Yeast!I'd like to think we're moving in that direction. I know I've said it but dry yeast back in the day was questionable. It's much better now and our options are growing and beer fermented with dry yeast is better than ever. I'm ready to declare S-04 my dry ale yeast with Diamond as a lager option although I would like to try that Baja lager yeast that's been kicked around. If they keep coming up with great dry options I would absolutely give up liquid strains.
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Post by gusso on Aug 22, 2022 18:15:06 GMT -6
I use dry yeast about 75% of the time. Maybe more.
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Post by brewbama on Aug 23, 2022 5:33:23 GMT -6
…. I would like to try that Baja lager yeast that's been kicked around. … I’m still in for $25 if someone wants to pull the trigger. Sent from my iPhone using Tapatalk
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Post by Ken on Aug 23, 2022 7:46:57 GMT -6
…. I would like to try that Baja lager yeast that's been kicked around. … I’m still in for $25 if someone wants to pull the trigger. Sent from my iPhone using Tapatalk Has there been any other talk on AHA about this stuff? I heard a number of people say they bought the big brick of it. That's a lot of yeast to buy without knowing how it performs or how the character is.
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