[papapelon]

I have a Vienna Lager that I have been lagering at 34F for three weeks.  I wanted that to stay at that temp for at least another week and possibly another three weeks for a total of 6 weeks.  I brewed an ale this past weekend and I have only my chest freezer, occupied by the Vienna Lager, for a temperature controlled environment so I bumped up the temp to 65F for the ale.  If I drop the temp down to 34F after the ale is done, will I see any negative effects on the Vienna Lager having sat at 65F for two weeks?  Am I better off to just call the lagering done and bottle it?  Any help is appreciated!

[denny]

I don't think that will have any negative affects on your lager.

[davidgzach]

If you didn't perform a diacetyl rest, don't be surprised if you start to see some activity........

[denny]

If you didn't perform a diacetyl rest, don't be surprised if you start to see some activity........

I seems like fermentation should be finished by this point.

[weithman5]

in terms of the diactyl rest if you completed fermentation before lagering this likely won't see much activity.  i usually ferment my lagers for 4 weeks. 

i assume you are brewing a 5 gallon batch if possible put it in a large styrofoam cooler with some ice packs around it. this will keep the temp down if you change them every day to 65. you may not be able to put the lid on but you could cover it with a blanket.

even here in chicago, in my garage i can put my lagers (only 2gallon) in a cooler with ice packs. i change them every day, twice a day when it gets warmer and my cooler temp stays at 50.

[weithman5]

oh, that said, it probably won't affect your outcome to just bump the temp briefly

[a10t2]

I seems like fermentation should be finished by this point.

I think he meant that CO₂ will come out of solution.

[davidgzach]

I seems like fermentation should be finished by this point.

I think he meant that CO₂ will come out of solution.

If diacetyl was produced in primary fermentation and a diacetyl rest was not done, the yeast will start to clean the beer if it is raised to 65F and you will see some activity.  I've seen it with my own two eyes!

Dave

[brewmichigan]

I seems like fermentation should be finished by this point.

I think he meant that CO₂ will come out of solution.

If diacetyl was produced in primary fermentation and a diacetyl rest was not done, the yeast will start to clean the beer if it is raised to 65F and you will see some activity.  I've seen it with my own two eyes!

Dave

Germans don't do diacetyl rests. If the beer was fermented properly, a diacetyl rest is not always necessary. Also, I wouldn't think the yeast would become active just to clean up diacetly. That should only happen if fermentation is not complete.

[a10t2]

If diacetyl was produced in primary fermentation and a diacetyl rest was not done, the yeast will start to clean the beer if it is raised to 65F and you will see some activity.  I've seen it with my own two eyes!

Most likely you're seeing CO₂ coming out of solution, not yeast activity.

It's possible that the beer didn't attenuate fully and warming it back up would result in the yeast becoming active again, but I don't think it's likely.

[tschmidlin]

Reduction of diacetyl by yeast should not be releasing any CO2, it's not part of that pathway.

[denny]

Germans don't do diacetyl rests. If the beer was fermented properly, a diacetyl rest is not always necessary. Also, I wouldn't think the yeast would become active just to clean up diacetly. That should only happen if fermentation is not complete.

To all of the above...yep!

[davidgzach]

I seems like fermentation should be finished by this point.

I think he meant that CO₂ will come out of solution.

If diacetyl was produced in primary fermentation and a diacetyl rest was not done, the yeast will start to clean the beer if it is raised to 65F and you will see some activity.  I've seen it with my own two eyes!

Dave

Germans don't do diacetyl rests. If the beer was fermented properly, a diacetyl rest is not always necessary. Also, I wouldn't think the yeast would become active just to clean up diacetly. That should only happen if fermentation is not complete.

Americans, Japanese, Belgians, Indians and Eskimos also don't do diacetyl rests so long as they pitch the correct amount of yeast and ferment properly.  However, with some strains a diacetyl rest is still recommended.  See below from the Wyeast website:

"YEAST STRAIN: 2206  |  Bavarian Lager
Used by many German breweries to produce rich, full-bodied, malty beers, this strain is a good choice for bocks and dopplebocks. A thorough diacetyl rest is recommended after fermentation is complete."
 
All I'm saying is if there is some, and the beer is raised to diacetyl temps, then there will be activity in the airlock.  This just happended to me recently and the beer was feremented out.  Could it have been degassing, I guess, but it lasted a few days.

Dave

[denny]

But if the beer is fermented out, how could there be continued fermentation activity?  And FWIW, I use 2206 frequently and I don't remember ever having it throw diacetyl.

[davidgzach]

That I cannot answer.  I figured it was the yeast cleaning up.  It was at 1.013 and the top end of the attenuation for the strain.  Maybe it fermented out further?  I'll take another gravity reading today as I'm kegging it.  I hear ya on the 2206 as well.  The sample tasted great.

I must be missing something.  I need a beer.....