Diacytel Rest - Is it necessary?

[permo]

Its winter here in North Dakota, and my garage heat keeps me at about 49-51 degrees all winter long. I just brewed up a nice pale lager beer, very simple and a big healthy pitch of WLP810 (san fran lager) yeast. My beer is happily bubbling away at about 53-54 degrees fermenter temp.

I really don't want to raise the temperature of my garage up to 60 degrees for a day or two for a diacytel rest. I am wondering if just leaving the beer on the yeast for an extra week or two would accomplish the same thing? It is my understand the yeast will still clean up the diacytel but it will be a slower process.

Thoughts?

 

[dmtaylor]

You're fine, just keep it there. If you taste it you might find that there's no diacetyl in there anyway. If not then you can skip the rest and the extra time altogether.

 

[tgolanos]

I've made about a half-dozen lagers at this point and I've never had detectable diacytel in any of them. That being said, I have always done a D-rest for at least a day, but I can easily move my fermenter around my house. Is your garage attached or detached?

Take a small sample and taste it first to find out if there's any diacytel in there. Ultimately, I think you're fine leaving it in your garage for another week without raising the temp. Most yeast strains I use say they're modified to minimize diacytel production anyway, so yours probably are too.

 

[Gavin C]

Its winter here in North Dakota, and my garage heat keeps me at about 49-51 degrees all winter long. I just brewed up a nice pale lager beer, very simple and a big healthy pitch of WLP810 (san fran lager) yeast. My beer is happily bubbling away at about 53-54 degrees fermenter temp.

I really don't want to raise the temperature of my garage up to 60 degrees for a day or two for a diacytel rest. I am wondering if just leaving the beer on the yeast for an extra week or two would accomplish the same thing? It is my understand the yeast will still clean up the diacytel but it will be a slower process.

Thoughts?

If you decide to ramp the temperature toward the tail-end of fermentation when the beer is very close to FG and/or a diacetyl rest for a period of time the easiest way would be to bring the beer inside to a warm part of the house. I'm guessing that is heated this time of the year in ND.

Having said that, traditional historic larger fermentation does not involve a warmer phase. Diacetyl will reduce over time even at cold temperatures. But it will take longer owing to the greatly slowed lager-yeast metabolism at these temperatures.

(Traditional is top left)

 

[Jwin]

Put a industrial(big black) trash bag over your fermenter. Place 3 of the tie flaps under it. Tape the fourth to a small space heater (lasko my heat is good)
Run it for about 10 hours and check the temp. Should work for ya. I just finished an ale like this in my basement. Temp dropped and was around 40* F. Got it down to 1.009 from 1.1 with pacman.

 

[permo]

Thanks for replies folks. It is a heated garage and I could just raise it to 60 for a day if need be. I will monitor it. It is a 15 gallon conical so moving it inside is probably not going to be feasible at this point. It is supposed to warm into the 40s here this weekend so it may not take much heat to ramp to 60 degrees or so after 1 week of fermenting. The OG was only 1.053 so I would think after a week of ferment we should be nearing terminal gravity.

 

[poptarts]

jealous of heated garage

 

[Gavin C]

Thanks for replies folks. It is a heated garage and I could just raise it to 60 for a day if need be. I will monitor it. It is a 15 gallon conical so moving it inside is probably not going to be feasible at this point. It is supposed to warm into the 40s here this weekend so it may not take much heat to ramp to 60 degrees or so after 1 week of fermenting. The OG was only 1.053 so I would think after a week of ferment we should be nearing terminal gravity.

Moving a 15gallon conical. No thanks. With you there.

Should be at or close to FG after a week. Seems like the optimal time for a temperature ramp if the gravity is within 1-2 plato of FG.

An ambient of 60F at the tail end sounds ideal if the beer can slowly rise to 68F over a couple of days. I like to do that with lagers.

 

[lilbova3]

If you decide to ramp the temperature toward the tail-end of fermentation when the beer is very close to FG and/or a diacetyl rest for a period of time the easiest way would be to bring the beer inside to a warm part of the house. I'm guessing that is heated this time of the year in ND.



Having said that, traditional historic larger fermentation does not involve a warmer phase. Diacetyl will reduce over time even at cold temperatures. But it will take longer owing to the greatly slowed lager-yeast metabolism at these temperatures.



(Traditional is top left)

I know there are a lot of threads out there about a D-rest for ales too but could this timetable carry over for ales as well? I've had a few diacetyl problems and don't believe it's from infection or a high fermentation temp. I like to ferment cool, ambient temp around 59-60, and do small batches with only about 3 gallons into the fermenter so I wouldn't think the temp could get too high during fermentation. I usually keep on the yeast cake for two weeks. If I go three weeks it looks like diacetyl would be reduced even more? I know time can heal a lot of wounds in homebrewing.

 

[Gavin C]

I know there are a lot of threads out there about a D-rest for ales too but could this timetable carry over for ales as well? I've had a few diacetyl problems and don't believe it's from infection or a high fermentation temp. I like to ferment cool, ambient temp around 59-60, and do small batches with only about 3 gallons into the fermenter so I wouldn't think the temp could get too high during fermentation. I usually keep on the yeast cake for two weeks. If I go three weeks it looks like diacetyl would be reduced even more? I know time can heal a lot of wounds in homebrewing.

Ramping temperatures toward the tail end of fermentation (when the beer is within a few points of FG) is something many, including myself do to insure maximal attenuation and to allow the optimal conditions for ale yeasts to metabolise unwanted fermentation byproducts.

Typically a day or so at these temperatures (68F) is all that's needed. This is very useful I believe with hybrids like Alt and Kolsch which are more lager-like in their desired flavors.

You can see more on this type of fermentation profile here in this Alt recipe.

I then crash cool and package the beer in my usual manner.

 

[PGEduardo]

Just let it ride, cold crash as usual and then keg. Once it has been kegged, then bring it into the warm house for a week or so.

I had a Mexican Lager that had noticeable diacetyl after performing a D-rest, cold crashing, lagering and kegging. I was worried that there wouldn't be enough yeast in there to perform the cleanup but after a week at room temp it was gone! Beer turned out great!

 

[jpakstis]

I made a lager for my parents' Christmas party and basically just left it in a fridge with the temp set around 50 for a month or so and didn't change the temp in any way until I hit the target FG and cold crashed it. It came out so great that I'm doing the same thing with one now, except luckily our garage is around 45-50 so I don't need to keep it in the fridge (our December in New England was mainly in the 50's and 60's).

Based on my primitive research, one of the main reasons for the diacetyl rest is so that you can speed the process up a little bit. If you take your time (like they would do in "olden" times) it clears up and cleans up on its own. The only other thing I did (and plan on doing) is adding gelatin toward the end to really clear the beer and that last batch was sparkling at my parents' party.

 

[DurtyChemist]

I'd heat it up. My past three lagers tasted like Diacetyl. It will go away with this but it takes a long time. I have temp control too. I'd do it around day 4 or 5.

 

[permo]

Its day 8. 1.053 down to 1.018. Fermentation started at 52-54 degrees. Slowly ramped it and now it is at 60 degrees to finish out for another week. Samples taste good.