Lager fermentation: when to dump yeast?

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stealthfixr

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Doing my first lager, a Doe Equis clone with Saflager 34/70 yeast. Started fermentation (OG 1.050) at 55F and after four days let it free rise to 68F where it stayed for 2 days and the FG was achieved at 1.009. I then dropped it no more than a couple degrees at a time, no more than 5 degrees in a 24-hour period down to 38F, where it has been for a week. Samples taste fantastic.

I am not new to brewing, just lagers. I researched here and elsewhere about when to dump the yeast, but cannot find the answer. I believe the lager yeast does a clean-up phase during lagering, and many instructions say to rack to a secondary before lagering. I am using a Spike CF-5 conical, which is really more of a unitank. The samples are pretty close to clear already.

With an ale, I would have collected/dumped the yeast soon after a cold crash...but this was not a cold crash. Is it the same for a lager, or does not mess up the lagering phase if you do? Do lager's sit on their yeast the entire time?

Probably overthinking this, but still cannot find an answer that seems to fit a unitank situation. Thanks in advance!
 

CRZ

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The clean up happens at the high temperature. This is a very important step for lagers.
sounds like you did everything good.
I cold crash right after FG. Collect the yeast then use gelatin. After 24hrs of finning I rack into to kegs. To lager is to sit in the cold and age until ready to drink.
 

Vale71

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The yeast doing the cleaning up is the yeast that is in suspension in the beer, not the one that has dropped and just sits there slowly dying. Even after primary there are millions of cells per milliliter of unfiltered beer. It follows that you should dump the yeast as soon as it collects in the cone, letting it sit there is just asking for autolysis flavors.
 

dmtaylor

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Contrary to popular belief, there should be no hurry in getting rid of settled yeast in a homebrew setting. It takes at least 9 or 10 weeks for autolysis to begin, IF it will even begin. In fact it is better to keep all the yeast in the beer until there is absolutely zero fermentation activity and the beer is clear. This will allow the yeast enough time to clean up after themselves, which includes absorption of off-flavors like diacetyl and sulfur. Patience, as usual, is a virtue. Don't be in any hurry to dump the yeast.
 

Vale71

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Autolysis begins during primary fermentation. This is based on scientific facts and not popular "belief".
Again, yeast in the cone has no contact with the beer and cannot physically act upon it in any way.
 

Barbarossa

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I was wondering also about the process. I don't mean to hijack the thread but, after the three week fermentation, a two days D-rest, is it bad if I cold crash straight to 35f and lager for four weeks? I think I read somewhere that the cold crash can put the yeast to sleep and could impact the lagering or something.
 

dmtaylor

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I was wondering also about the process. I don't mean to hijack the thread but, after the three week fermentation, a two days D-rest, is it bad if I cold crash straight to 35f and lager for four weeks? I think I read somewhere that the cold crash can put the yeast to sleep and could impact the lagering or something.
Great question. YES, this is "bad", or not ideal. Yeast will eat diacetyl. They will eat it much faster at warm temperatures than cold temperatures. If you want diacetyl in the beer, then by all means, chill it right down, and/or remove all your bottom-fermenting yeast from the bottom.
 

CRZ

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OP did a quick lager method. Raising the temp will cause the yeast to clean up way faster and there should be no diacetyl.
 

Jag75

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Lagers gave me the reason to purchase a tilt . When the fermentation is 75% done i start to ramp the temp up 3 degrees a day until its in the high 60's. I hold it there for a few days for rest . Then I drop the temp down 3 degrees a day until its 38f. Then I keg . This process has worked really well . Sounds like you've done the basically the same and have a tasty beer 🍺.
 
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