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First time lager - diacetyl rest?

http://terrencetheblack.com/forum/viewtopic.php?f=19&t=13475

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First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 3:19 pm
by brewerTristan
So I brewed my first lager almost (a german pilsner) about a month ago. I'm just about to start the lagering process and wanted to double check a few things:

The beer has been fermenting at 50 F. On Tuesday it will have been a month since I brewed it. I don't know whether I should do a diacetyl rest, but I figure it can't hurt. Am I correct in thinking I should bring up the temperature by about 10 degrees for a few days and then crash it down to lagering temperature?

Also, should I transfer to a secondary fermenter? And how long should I lager for and at what temperature? I was thinking a month at 40 F.

Thanks for the help.

Re: First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 6:38 pm
by BDawg
FIrst, taste it. If it tastes buttery (think movie popcorn), then yes, by all means do the diacetyl rest.

Usually it's best if the yeast is still active, like in the last 25% or so of the expected attenuation range.

example:
1.050 OG 1.010 target FG
3/4 of the way down from 1.050 to 1.010 would be at 1.020 => when the beer hits 1.020 do the diacetyl rest by raising the temp to around 60F for 3 days.
Then, you lower the temp a couple degrees per day down to the low 30's for lagering.

Alternatively, if you pitch a new starter that is at high krausen, that is kinda like krausening and the active yeast will eat up all the diacetyl too (but you must utilize the same temp regime - raise the temp, pitch the starter, let it go for 3 days, then slowly drop to lagering temps)

HTH-

Re: First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 6:50 pm
by brewerTristan
BDawg wrote:FIrst, taste it. If it tastes buttery (think movie popcorn), then yes, by all means do the diacetyl rest.

Usually it's best if the yeast is still active, like in the last 25% or so of the expected attenuation range.

example:
1.050 OG 1.010 target FG
3/4 of the way down from 1.050 to 1.010 would be at 1.020 => when the beer hits 1.020 do the diacetyl rest by raising the temp to around 60F for 3 days.
Then, you lower the temp a couple degrees per day down to the low 30's for lagering.

Alternatively, if you pitch a new starter that is at high krausen, that is kinda like krausening and the active yeast will eat up all the diacetyl too (but you must utilize the same temp regime - raise the temp, pitch the starter, let it go for 3 days, then slowly drop to lagering temps)

HTH-


So what you are saying is that I may have missed the chance to do the rest? There doesn't appear to be much activity going on in the carboy. I suppose I will have to go by taste and also take a gravity reading to be sure that it is finished. What about moving to a new carboy? Is that in order?

Re: First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 7:25 pm
by Mylo
brewerTristan wrote:Am I correct in thinking I should bring up the temperature by about 10 degrees for a few days and then crash it down to lagering temperature?


Let me re-emphasize something that BDawg said that you might have missed. Slowly (a degree an hour max) bring the beer down to lagering temps. If you crash it, you will force the yeast to flocculate out. You want them up in suspension during the lagering process.


Mylo

Re: First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 7:39 pm
by brewerTristan
Mylo wrote:
brewerTristan wrote:Am I correct in thinking I should bring up the temperature by about 10 degrees for a few days and then crash it down to lagering temperature?


Let me re-emphasize something that BDawg said that you might have missed. Slowly (a degree an hour max) bring the beer down to lagering temps. If you crash it, you will force the yeast to flocculate out. You want them up in suspension during the lagering process.


Mylo


Thank you for catching that. I think I sort of knew it, but I wasn't careful with my terminology (crashing). Does this also mean that I shouldn't transfer to a secondary? or will there be plenty of yeast still in suspension if I do this? Should I handle the temperature change in a similar fashion in the secondary?

Re: First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 8:09 pm
by Mylo
brewerTristan wrote:Thank you for catching that. I think I sort of knew it, but I wasn't careful with my terminology (crashing). Does this also mean that I shouldn't transfer to a secondary? or will there be plenty of yeast still in suspension if I do this? Should I handle the temperature change in a similar fashion in the secondary?


In the immortal words of Chris White.... "it depends". If you are doing your primary in a bucket - then you should definitely get it into a carboy or keg - because lagering is going to take 6-8 weeks, and you don't want your beer exposed to oxygen for that long. For those that keg, like me. My "secondary" is my bright tank (which is synonymous with my serving tank - since I rarely rerack out of laziness). There should be enough in suspension to do the cleanup. When you rack you can suck up a little of the last yeast that flocculated, if you want. For those that bottle and don't have kegs - I'm not sure if they choose to rack to a secondary for lagering. I think I probably would if I was in that situation.

No matter what your process is, I urge you to avoid the possibility of oxidation by pre-purging any vessel that you rack to with CO2.


Mylo

Re: First time lager - diacetyl rest?

Posted: Sun Mar 15, 2009 8:14 pm
by brewerTristan
Mylo wrote:
brewerTristan wrote:Thank you for catching that. I think I sort of knew it, but I wasn't careful with my terminology (crashing). Does this also mean that I shouldn't transfer to a secondary? or will there be plenty of yeast still in suspension if I do this? Should I handle the temperature change in a similar fashion in the secondary?


In the immortal words of Chris White.... "it depends". If you are doing your primary in a bucket - then you should definitely get it into a carboy or keg - because lagering is going to take 6-8 weeks, and you don't want your beer exposed to oxygen for that long. For those that keg, like me. My "secondary" is my bright tank (which is synonymous with my serving tank - since I rarely rerack out of laziness). There should be enough in suspension to do the cleanup. When you rack you can suck up a little of the last yeast that flocculated, if you want. For those that bottle and don't have kegs - I'm not sure if they choose to rack to a secondary for lagering. I think I probably would if I was in that situation.

No matter what your process is, I urge you to avoid the possibility of oxidation by pre-purging any vessel that you rack to with CO2.


Mylo


Well I'm fermenting in a glass carboy, so no worries about oxygen. I think I'll probably rack to a second carboy and then lager in that. I'll be sure to purge with co2.

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