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Post by denny on Apr 28, 2022 14:28:23 GMT -6
I moved it to a warmer spot and I'm just keeping an eye on it. I don't know why but I don't have any confidence in this. Probably because in the old days you just made some wort and dropped in your yeast which is what this feels like. Then stirplates came along and now you were in the cool club. Now stirplates are no good and I'm equating this process with pre-stirplate days. Newer is not necessarily better. I'm not exactly sure where the idea of stir plates came from. Yeast manufacturers don't use them. Breweries don't use them. Where did homebrewers get the idea that it was a good thing?
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Post by denny on Apr 28, 2022 14:31:33 GMT -6
Update: I made the starter this morning. My standard volume for a lager starter is 1500ml of water and 5.2 ounces of DME. I forget where that falls in the OG range but this is how I have been doing it for lagers for years with [what I consider to be] great results. I chilled the wort and got it into the gallon jug and shook. And shook and shook. It's a good amount of liquid in a 1-gallon jug. Then I carefully opened the pack of WLP940, poured it in, covered it loosely with sanitized foil, gave it a gentle swirl and it's sitting on my kitchen table awaiting action tomorrow. I hope it's ready. Do I give it a swirl every time I walk past it or just leave it alone? You can swirl it occasionally if you want to, but you don't need to. I use 1 qt. water and 3 oz. DME for both ales and lagers. Technically, 1500 ml is too much unless you have a bigger jug. But we're talking about homebrewing....close enough is good enough. FWIW, I'm right now making a 1 qt. starter for a 1.082 tripel I'm brewing tomorrow. I'm a bit concerned about the OG for an SNS but I'll never know unless I try it.
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Post by Ken on Apr 29, 2022 7:31:10 GMT -6
Okay well... I have a visible krauesen on the top of this starter so everything does appear to be working well. I don't know if has worked BETTER than a stirplate but activity has been achieved. I plan to brew late this afternoon and pitch around 7pm and not sure if this thing will be at HIGH krauesen (kraeusen? krausen? krauseusueuaun?) or not but things look ready to launch. Thanks beerheads!
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Post by Ken on Apr 29, 2022 10:24:07 GMT -6
Okay, so now a question: Why does this process work better than a flask on a stirplate? I shook this vessel until a good 90% of the liquid had turned to foam but a few minutes after I pitched the yeast, the foam had subsided and it looked like a regular old dead starter with nothing happening. What is it about shaking that is better than using pure O2 in a flask and just letting THAT sit there for 24 hours (or whatever)?
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Post by denny on Apr 29, 2022 10:28:49 GMT -6
Okay, so now a question: Why does this process work better than a flask on a stirplate? I shook this vessel until a good 90% of the liquid had turned to foam but a few minutes after I pitched the yeast, the foam had subsided and it looked like a regular old dead starter with nothing happening. What is it about shaking that is better than using pure O2 in a flask and just letting THAT sit there for 24 hours (or whatever)? No stir bar to cause cell shear. No crash, decant cycle so the yeast is fresher and healthier.
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Post by Ken on Apr 29, 2022 10:36:25 GMT -6
Okay, so now a question: Why does this process work better than a flask on a stirplate? I shook this vessel until a good 90% of the liquid had turned to foam but a few minutes after I pitched the yeast, the foam had subsided and it looked like a regular old dead starter with nothing happening. What is it about shaking that is better than using pure O2 in a flask and just letting THAT sit there for 24 hours (or whatever)? No stir bar to cause cell shear. No crash, decant cycle so the yeast is fresher and healthier. I was saying "flask with wort and pure O2 but no stirplate/stirbar". What if starter wort was added to a flask with pure O2 and yeast was added and you just left that sitting there for 24 hours? I'm not advocating for this since I am not a yeast expert. I'm just trying to wrap my head around the variables and have better understanding for why one thing works and something else does not.
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Post by denny on Apr 29, 2022 13:19:13 GMT -6
No stir bar to cause cell shear. No crash, decant cycle so the yeast is fresher and healthier. I was saying "flask with wort and pure O2 but no stirplate/stirbar". What if starter wort was added to a flask with pure O2 and yeast was added and you just left that sitting there for 24 hours? I'm not advocating for this since I am not a yeast expert. I'm just trying to wrap my head around the variables and have better understanding for why one thing works and something else does not. I think the scenario you describe sounds substantially the same. Since the purpose of shaking is to saturate the wort with O2, it would be the same thing.
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Post by denny on Apr 30, 2022 11:21:30 GMT -6
OK, since my wort was so high gravity I actually did some aeration this time to give my SNS some help. I had positive pressure in the airlock in 2 hours and substantial fermentation in 6 hours.
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Post by zymot on May 2, 2022 17:41:05 GMT -6
No stir bar to cause cell shear. No crash, decant cycle so the yeast is fresher and healthier. I was saying "flask with wort and pure O2 but no stirplate/stirbar". What if starter wort was added to a flask with pure O2 and yeast was added and you just left that sitting there for 24 hours? I'm not advocating for this since I am not a yeast expert. I'm just trying to wrap my head around the variables and have better understanding for why one thing works and something else does not. No science here. If you pour your starter into a flask, pitch your yeast then flush with oxygen, what do the yeast see? Regular air, dissolved in the wort. Air which is mostly nitrogen. As far as I know, nitrogen does nothing for yeast. I guess if you replaced the air in the flask with pure O2, what ever gas makes it's way into the wort will be mostly oxygen, not mostly nitrogen. So I am going believe O2 in the flask is better then plain old air. So what about SNS? What does that get you? I visualize yeast cells in contact with more air. The more foam, the more contact with the gas in the vessel. This works with the idea if a 1/4 wort, 3/4 air. When I invert and exaggerated the ratio, say 1/10 air and 9/10 wort, I visualize the yeast are going touch almost exclusively the gas dissolved in the wort. So that part of the process makes sense to me. Now there is a bunch if biology I do not know. Aerobic growth, and all that other junk. But if I concentrate on oxygen is good for the kind of yeast growth home brewers are looking for and am Leary that stir bars and stir plates shred yeast cells (Auntie Em Auntie Em it's a stir bar!) I can see how I might be doing more of a good thing and less if a bad thing. The last SNS starter I made, I flushed the container with O2 and did the shake thing, let the wort settle a but, one more O2 flush. Worked as good as I could ever expect.
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Post by Ken on May 2, 2022 18:56:08 GMT -6
I somehow got on the bandwagon that yeast need a good amount of O2. Over on the AHA forum I think I started a conversation about this because I heard many, many homebrewers say that they don't bother using an O2 setup anymore. But IIRC, one of the yeast priests over there confirmed that there are negative things that can happen when the yeast doesn't have enough O2. I have been adding pure O2 to fresh wort forever and I just did it last Friday. I also used to add it to starter wort. This SNS starter seemed to work fine. The yeast was getting close to its BEST BY date (May 13) and it was active in about 24 hours and after pitching into the wort on brewday I had quick and strong activity so I cannot complain.
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Post by brewbama on May 3, 2022 6:43:20 GMT -6
This is my take on O2 requirements in brewing.
Brian Rabe did a test where he measured the O2 levels in water, added a yeast/sugar solution, and in 20 min the water was at zero ppm O2. It remained at zero for days. I do not believe the test vessel was devoid of air. He did not report on testing for other gases.
Wort, whether in an SnS starter or in a fermenter, is basically a yeast/sugar/water solution in the presence of air.
In my mind, that means active yeast may very well need the O2 initially for their aerobic phase but consume it relatively quickly. I haven’t studied yeast to the point that I can say they need more O2 than what is naturally provided to them. However, they live in the real world where we are surrounded by air. So, I imagine they are pretty good with getting their O2 requirements from the environment where they live. IOW, I don’t believe they are so delicate that air is insufficient for their needs.
After the 20 min O2 consumption, I believe they transition into their anaerobic phase of life.
Years ago I bought an O2 tank, sintered stone, stir plate, flasks, etc, etc. I haven’t used them in years. Partly because I use dry yeast but partly because I just don’t believe they’re required. Maybe I’m wrong.
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Post by Ken on May 3, 2022 7:46:45 GMT -6
This is my take on O2 requirements in brewing. Brian Rabe did a test where he measured the O2 levels in water, added a yeast/sugar solution, and in 20 min the water was at zero ppm O2. It remained at zero for days. I do not believe the test vessel was devoid of air. He did not report on testing for other gases. Wort, whether in an SnS starter or in a fermenter, is basically a yeast/sugar/water solution in the presence of air. In my mind, that means active yeast may very well need the O2 initially for their aerobic phase but consume it relatively quickly. I haven’t studied yeast to the point that I can say they need more O2 than what is naturally provided to them. However, they live in the real world where we are surrounded by air. So, I imagine they are pretty good with getting their O2 requirements from the environment where they live. IOW, I don’t believe they are so delicate that air is insufficient for their needs. After the 20 min O2 consumption, I believe they transition into their anaerobic phase of life. Years ago I bought an O2 tank, sintered stone, stir plate, flasks, etc, etc. I haven’t used them in years. Partly because I use dry yeast but partly because I just don’t believe they’re required. Maybe I’m wrong. I hear everything you're saying and like you I am not a yeast expert by any stretch. I consider yeast to be the "miracle" part of the process and the Brewers don't make beer, yeast make beer part. I have absolutely made batches of beer where something wasn't quite right. The beer wasn't contaminated but it was just slightly off and I always wonder about the yeast's health and general condition. I'm sure you're right that the yeast can get their O2 requirements from the air and I agree that they're living in the real world with sugar, water and air but then their environment is sealed off so that no additional O2 can be supplied. Beer fermented with yeast that is in poor-health (or is tired, depleted, etc) is probably not good beer. As humans, we generally get all of our needs on a daily basis but some days are better than others. I guess that in the absence of any formal yeast training, I want to try to give the yeast everything they could need. Clearly the beer in our glass is the test. If it's good or great, then you're doing it right.
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Post by denny on May 3, 2022 11:21:11 GMT -6
I somehow got on the bandwagon that yeast need a good amount of O2. Over on the AHA forum I think I started a conversation about this because I heard many, many homebrewers say that they don't bother using an O2 setup anymore. But IIRC, one of the yeast priests over there confirmed that there are negative things that can happen when the yeast doesn't have enough O2. I have been adding pure O2 to fresh wort forever and I just did it last Friday. I also used to add it to starter wort. This SNS starter seemed to work fine. The yeast was getting close to its BEST BY date (May 13) and it was active in about 24 hours and after pitching into the wort on brewday I had quick and strong activity so I cannot complain. Yeast do need a good amount of O2, and they get it from SNS. This is the other half of why this is an effective method....https://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons
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Post by denny on May 3, 2022 11:22:46 GMT -6
This is my take on O2 requirements in brewing. Brian Rabe did a test where he measured the O2 levels in water, added a yeast/sugar solution, and in 20 min the water was at zero ppm O2. It remained at zero for days. I do not believe the test vessel was devoid of air. He did not report on testing for other gases. Wort, whether in an SnS starter or in a fermenter, is basically a yeast/sugar/water solution in the presence of air. In my mind, that means active yeast may very well need the O2 initially for their aerobic phase but consume it relatively quickly. I haven’t studied yeast to the point that I can say they need more O2 than what is naturally provided to them. However, they live in the real world where we are surrounded by air. So, I imagine they are pretty good with getting their O2 requirements from the environment where they live. IOW, I don’t believe they are so delicate that air is insufficient for their needs. After the 20 min O2 consumption, I believe they transition into their anaerobic phase of life. Years ago I bought an O2 tank, sintered stone, stir plate, flasks, etc, etc. I haven’t used them in years. Partly because I use dry yeast but partly because I just don’t believe they’re required. Maybe I’m wrong. Based on the research I've done, yeast do not have discreet phases.
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Post by brewbama on May 3, 2022 21:03:55 GMT -6
Well, they’re doing something without O2 for a week because the data clearly showed O2 went to zero in ~20 min and stayed there for days afterwards until he finally shut down the test.
While I have you on the horn I want to run something by you: I have been playing with rehydrating again this time using Go-Ferm. The routine is to rehydrate, wait 15 min the stir into solution. Instead of stirring this time, I am thinking about shaking the begeezies out of it similar to SnS just before pitching. Have you ever done anything like that? If so, what was the outcome?
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