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Did I kill my Yeast ?

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OATY1KENOBE

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Hi Guys,

Firstly, thanks for your responses on pitching onto yeast cakes..... Now I have a new issue.... My (PALE ALE) fermentation has stalled from 1.037 to 1.020. It is in a Fermzilla. I pre-set my spunding valve ( blow-tie ) to approx 8PSI on an empty keg with CO2, & set my fridge to 18C ( Safeale S-04) however when I came home from work the next day the fermzilla was sitting at 25PSI. I immediately cracked the blow-tie and let it down to 8-9 PSI again. Activity seamed fine...… When all the commotion had calmed down days later, I took a hydrometer reading and it was at 1.020, I bumped up the temp to 22 to try and re-invigorate the yeast. Two days later - nothing. I took the fermzilla out of the fridge and shook the shit out of it to fully release the yeast cake and put it back in. 2 days later still at 1.020. So I took it out again, shook the shit out of it again then sanitized and pitched more yeast,....now my pressure was lost ( sitting at about 2 PSI ) two days later , still 1.020. so I bumped temp up to 24C in a last ditch effort..... I suspect the initial 25PSI has killed the bulk of the yeast, however I have not had issues in the past when PSI went too high initially (this was in a converted Corny keg )??

** I hit all my expected numbers during the brew,...… and OG. My Mash PH was 5.42. I use R.O water ( however, I did use a brand new system which gave me a low starting PH , so my salt additions were minimal. 1/2 teaspoon gypsum ) the RO system was rinsed etc properly. I mashed at 64-65 (20mins) to start then raised to 68 for the remainder. Starch conversion test showed full conversion. I conditioned my malt for the first time.


So,.. I have a few questions:

1. Shouldn't have the second pitch cleaned up the remaining Wort ? My expected FG was 1.007. If not why not ?
2. What methods are best for pressure fermenting ? Some bloke on you-tube looked like he knew what he was doing pitches his yeast then pumps his fermentasaurus up to 30 PSI with his CO2 bottle ??
3. I've since read that for ALES perhaps letting fermentation go for a day or two with a blow-off is best, then attach a spunding valve set to only about 3 PSI ?
4. For LAGERS, attach spunding valve straight away, but at what pressure should it sit ?

PLEASE don't tell me to "experiment". I live 1500Km's away from my nearest home brew supplier and have had to learn everything from reading & you-tube... I don't have access to any 'clubs' or 'demo-nights' etc... I can't afford to 'experiment' when I can't be sure when I can get ingredients again......

Thanks for your info :)
 

Coalminer

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Hi Guys,

Firstly, thanks for your responses on pitching onto yeast cakes..... Now I have a new issue.... My (PALE ALE) fermentation has stalled from 1.037 to 1.020. It is in a Fermzilla. I pre-set my spunding valve ( blow-tie ) to approx 8PSI on an empty keg with CO2, & set my fridge to 18C ( Safeale S-04) however when I came home from work the next day the fermzilla was sitting at 25PSI. I immediately cracked the blow-tie and let it down to 8-9 PSI again. Activity seamed fine...… When all the commotion had calmed down days later, I took a hydrometer reading and it was at 1.020, I bumped up the temp to 22 to try and re-invigorate the yeast. Two days later - nothing. I took the fermzilla out of the fridge and shook the shit out of it to fully release the yeast cake and put it back in. 2 days later still at 1.020. So I took it out again, shook the shit out of it again then sanitized and pitched more yeast,....now my pressure was lost ( sitting at about 2 PSI ) two days later , still 1.020. so I bumped temp up to 24C in a last ditch effort..... I suspect the initial 25PSI has killed the bulk of the yeast, however I have not had issues in the past when PSI went too high initially (this was in a converted Corny keg )??

** I hit all my expected numbers during the brew,...… and OG. My Mash PH was 5.42. I use R.O water ( however, I did use a brand new system which gave me a low starting PH , so my salt additions were minimal. 1/2 teaspoon gypsum ) the RO system was rinsed etc properly. I mashed at 64-65 (20mins) to start then raised to 68 for the remainder. Starch conversion test showed full conversion. I conditioned my malt for the first time.


So,.. I have a few questions:

1. Shouldn't have the second pitch cleaned up the remaining Wort ? My expected FG was 1.007. If not why not ?
2. What methods are best for pressure fermenting ? Some bloke on you-tube looked like he knew what he was doing pitches his yeast then pumps his fermentasaurus up to 30 PSI with his CO2 bottle ??
3. I've since read that for ALES perhaps letting fermentation go for a day or two with a blow-off is best, then attach a spunding valve set to only about 3 PSI ?
4. For LAGERS, attach spunding valve straight away, but at what pressure should it sit ?

PLEASE don't tell me to "experiment". I live 1500Km's away from my nearest home brew supplier and have had to learn everything from reading & you-tube... I don't have access to any 'clubs' or 'demo-nights' etc... I can't afford to 'experiment' when I can't be sure when I can get ingredients again......

Thanks for your info :)
Are you using a hydrometer or a refractometer to check your FG?
 

Malted Mick

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I had exactly the same pressure build up the first time I used my Fermzilla. I had an APA pitched with SAF-05 but had not preset the blowtie. Second day of fermentation when I checked the gauge was at the stop maybe about 35 psi. Not sure how long the event was but I reduced the pressure to 5 psi and held the temp at 18 C for another 8 days. Good news in that it was a very active fermentation and the pressure excursion did not effect my target FG. Going on my experience the yeast was uneffected in this instance.
 

Reg Holt

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S04 is a great yeast should really have done the job on your pale ale 25 PSI I shouldn't think would have killed it, stressed it out yes. Shaking is not advised with S04 or US 05 neither need aerating or oxygenating, or even hydrating. Its not as if its trying to ferment a high alcohol beer so can't say what went wrong. Your point 3 is OK for 4 the recommended is no more than 15 PSI but don't expect to get a lager.
 

golfandbrew

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As coalminer said...how are you measuring your gravity? Further to his point if using a refractometer, are you correctly calibrating it? If you're using a refractometer after fermentation have you adjusted for the presence of alcohol? Or better yet, just don't do it.

If you're using a hydrometer it's quite possible with the high pressure you're fermenting under there may be co2 in solution. It would be wise in this instance to toss your sample back and fourth between two glasses to get the co2 out of solution before taking your gravity reading.

Also, RDWHAHB. "Shaking the shit out of the fermenter" screams of unnecessary panic. Yeast are not as fragile as a lot of people can make them out to be. Are there optimal conditions for yeast, yes, but even these are more about flavour than they are about the yeast working or not working.

If you don't have time to experiment I would recommend being a bit more selective of where you get your information, myself included. Forums, blogs, YouTube, and even some monthly print publications will often be geared more towards the experimental brewer because a lot of us like to test these new or different ways of brewing. More about the journey and less about the destination you could say. This is not to say that any of these sources are right or wrong but more that maybe it's not what you're looking for right now as a brewer. For more tried and true processes with repeatable results I would recommend reading How to Brew by John Palmer. Simple Home Brewing by Drew Beechum and Denny Conn would probably also be good. I'll be honest I have not read this book but I wouldn't hesitate to trust the authors behind it.
 

OATY1KENOBE

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Hi Guys,

Firstly, thanks for your responses on pitching onto yeast cakes..... Now I have a new issue.... My (PALE ALE) fermentation has stalled from 1.037 to 1.020. It is in a Fermzilla. I pre-set my spunding valve ( blow-tie ) to approx 8PSI on an empty keg with CO2, & set my fridge to 18C ( Safeale S-04) however when I came home from work the next day the fermzilla was sitting at 25PSI. I immediately cracked the blow-tie and let it down to 8-9 PSI again. Activity seamed fine...… When all the commotion had calmed down days later, I took a hydrometer reading and it was at 1.020, I bumped up the temp to 22 to try and re-invigorate the yeast. Two days later - nothing. I took the fermzilla out of the fridge and shook the shit out of it to fully release the yeast cake and put it back in. 2 days later still at 1.020. So I took it out again, shook the shit out of it again then sanitized and pitched more yeast,....now my pressure was lost ( sitting at about 2 PSI ) two days later , still 1.020. so I bumped temp up to 24C in a last ditch effort..... I suspect the initial 25PSI has killed the bulk of the yeast, however I have not had issues in the past when PSI went too high initially (this was in a converted Corny keg )??

** I hit all my expected numbers during the brew,...… and OG. My Mash PH was 5.42. I use R.O water ( however, I did use a brand new system which gave me a low starting PH , so my salt additions were minimal. 1/2 teaspoon gypsum ) the RO system was rinsed etc properly. I mashed at 64-65 (20mins) to start then raised to 68 for the remainder. Starch conversion test showed full conversion. I conditioned my malt for the first time.


So,.. I have a few questions:

1. Shouldn't have the second pitch cleaned up the remaining Wort ? My expected FG was 1.007. If not why not ?
2. What methods are best for pressure fermenting ? Some bloke on you-tube looked like he knew what he was doing pitches his yeast then pumps his fermentasaurus up to 30 PSI with his CO2 bottle ??
3. I've since read that for ALES perhaps letting fermentation go for a day or two with a blow-off is best, then attach a spunding valve set to only about 3 PSI ?
4. For LAGERS, attach spunding valve straight away, but at what pressure should it sit ?

PLEASE don't tell me to "experiment". I live 1500Km's away from my nearest home brew supplier and have had to learn everything from reading & you-tube... I don't have access to any 'clubs' or 'demo-nights' etc... I can't afford to 'experiment' when I can't be sure when I can get ingredients again......

Thanks for your info :)
Hydrometer,.... as stated :)
 

OATY1KENOBE

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S04 is a great yeast should really have done the job on your pale ale 25 PSI I shouldn't think would have killed it, stressed it out yes. Shaking is not advised with S04 or US 05 neither need aerating or oxygenating, or even hydrating. Its not as if its trying to ferment a high alcohol beer so can't say what went wrong. Your point 3 is OK for 4 the recommended is no more than 15 PSI but don't expect to get a lager.
Why not expect a lager ? i have had issues trying to get a 3.5% lager right -- any tips appreciated
 

OATY1KENOBE

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As coalminer said...how are you measuring your gravity? Further to his point if using a refractometer, are you correctly calibrating it? If you're using a refractometer after fermentation have you adjusted for the presence of alcohol? Or better yet, just don't do it.

If you're using a hydrometer it's quite possible with the high pressure you're fermenting under there may be co2 in solution. It would be wise in this instance to toss your sample back and fourth between two glasses to get the co2 out of solution before taking your gravity reading.

Also, RDWHAHB. "Shaking the shit out of the fermenter" screams of unnecessary panic. Yeast are not as fragile as a lot of people can make them out to be. Are there optimal conditions for yeast, yes, but even these are more about flavour than they are about the yeast working or not working.

If you don't have time to experiment I would recommend being a bit more selective of where you get your information, myself included. Forums, blogs, YouTube, and even some monthly print publications will often be geared more towards the experimental brewer because a lot of us like to test these new or different ways of brewing. More about the journey and less about the destination you could say. This is not to say that any of these sources are right or wrong but more that maybe it's not what you're looking for right now as a brewer. For more tried and true processes with repeatable results I would recommend reading How to Brew by John Palmer. Simple Home Brewing by Drew Beechum and Denny Conn would probably also be good. I'll be honest I have not read this book but I wouldn't hesitate to trust the authors behind it.
As stated, hydrometer readings at 18 -20C, and yes I made sure it was 'flat'
 

golfandbrew

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Might be a good idea to go back check your thermometer. You said you were using a new system so maybe your mash temps were higher than you thought and your wort less fermentable.
 

MHB

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The same gravity wort can have different fermentability.
Mind you from 1.037 to 1.020 is only ~46% apparent, I doubt you could get that low a fermentability into a wort made with quality modern malt.
Well there are ways but you would really have to work at killing off your beta-amylase before it made much maltose, it would take some doing. Which would require mashing in somewhere in the low to mid 70oC which means your thermometer would have to be out by miles.

Could be your pressure is a lot higher than you think and its crippling your yeast.
Mark
 

OATY1KENOBE

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Thanks Guys, any tips on pressure fermenting ? I'm especially interested in brewing Mid-strength Lagers, Pressure on lagers reduces esters and phenols right ? Should I attach the spunding valve straight up, or let the yeast do its thing for a bit first ?
 
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Thanks Guys, any tips on pressure fermenting ? I'm especially interested in brewing Mid-strength Lagers, Pressure on lagers reduces esters and phenols right ? Should I attach the spunding valve straight up, or let the yeast do its thing for a bit first ?
15 PSI straight off seems to be the go, I tried the pseudo lager and you will definitely notice the difference. Not that I am a big lager drinker.
 

OATY1KENOBE

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15 PSI straight off seems to be the go, I tried the pseudo lager and you will definitely notice the difference. Not that I am a big lager drinker.
Ok, last dumb question, do I pressure the fermenter up with CO2 from my bottle?.... I see that's how some do it on you-tube..... wouldn't I want as much O2 in there as possible for the yeast,.... (and let the CO2 build up naturally),.....or do they only need the oxygen that's in the liquid and a CO2 cap is irrelevant ??
 
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Ok, last dumb question, do I pressure the fermenter up with CO2 from my bottle?.... I see that's how some do it on you-tube..... wouldn't I want as much O2 in there as possible for the yeast,.... (and let the CO2 build up naturally),.....or do they only need the oxygen that's in the liquid and a CO2 cap is irrelevant ??
Read the instructions for the yeast most if not all of the Safale dry yeast need no oxygen sprinkle the yeast over the wort unless you are going to use a different yeast then the wort will need oxygenating/aerating. The gases from the ferment will be enough to add the pressure, set your spunding valve to 15 PSI no need for bottled gas.
 

OATY1KENOBE

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Read the instructions for the yeast most if not all of the Safale dry yeast need no oxygen sprinkle the yeast over the wort unless you are going to use a different yeast then the wort will need oxygenating/aerating. The gases from the ferment will be enough to add the pressure, set your spunding valve to 15 PSI no need for bottled gas.
Cool, Thanks WEAL , that's what I have been doing, wort gets oxygenated when I tip from my cube to fermenter through a large funnel but that just happens regardless.... just this time the blow tie got blocked and it went to 25PSI....
 
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