Lagering Before Complete Fermentation

[Dornbox]

So I have an Oktoberfest that the OG has been fairly stable for a few days but I have still have a stream of bubbles rolling through my spunding valve bath. I started a rapid D rest about 5 days ago by raising the tank temp abv 65°. I’m headed out of town tomorrow for 10 days. Should I let it stay high or bring it down to 40° ish overnight? I’m wicked sensitive to diacetyl and am really looking forward to drinking this one in October. Any insight would be sweet! Oh! Expected FG has been reached and the yeast is Wyeast 2633. Thanks!

 

[Josh Hughes]

If it’s done it’s done. Especially if you did a diacetyl rest already. Are you sure it has t dropped more since you checked? I can’t imagine it still fermenting if you were in the mid 60s for 5 days. Keg it and start lagering if it’s done.

 

[Dornbox]

@Josh Hughes. Well I’m using my tilt but I did do an physical gravity check a few days ago to verify. My spund valve is bubbling like an inner tube that has a slow leak when you hold it under water. Not a lot but it’s a constant stream and has been for 2-3 days.

https://www.brewersfriend.com/homebrew/recipe/view/1255594/rasputitsa-fest

 

[Josh Hughes]

Sounds like you use a tilt and do it how I do. Keg it and get that baby lagering

 

[Minbari]

I agree with @Josh Hughes . the bubbles could be from the raise in temp too. higher temp will expand the liquid and allow disolved co2 to come out. I would keg it.

even if it isnt done, it will finish in the keg.

 

[Dornbox]

@Minbari I totally didn’t think of the dissolved co2 which was created while the beer was spunding around 50°. I ran out of time but I dumped the yeast and turned off the chiller control off to let it free cool which should be around 45-50°. I also preset my chiller to around 38° and will have one of my buddies drop by in a day or so to turn the chiller back on.

many thanks for the advice gents!

 

[HighVoltageMan!]

When fermenting under pressure, I have notice that co2 keeps venting long after final gravity has been hit. I wish I had an explanation for this, but I don't. I typically ferment at 48-50F @ 4-7psi for a week and over the next seven days raise the temperature to the mid fifties and pressure to 20psi. I don't have a tilt, but I watch the venting from the fermenter (through a beer bottle filled with water). When the bubbles are 4 seconds apart, almost always at 13-14 days, I crash it. Typical FG's are 78-84%. If you brew a certain beer or style, ale or lager and have consistent methods, the progress of that beer is like clock work.

Crash it!!

 

[Minbari]

When fermenting under pressure, I have notice that co2 keeps venting long after final gravity has been hit. I wish I had an explanation for this, but I don't. I typically ferment at 48-50F @ 4-7psi for a week and over the next seven days raise the temperature to the mid fifties and pressure to 20psi. I don't have a tilt, but I watch the venting from the fermenter (through a beer bottle filled with water). When the bubbles are 4 seconds apart, almost always at 13-14 days, I crash it. Typical FG's are 78-84%. If you brew a certain beer or style, ale or lager and have consistent methods, the progress of that beer is like clock work.

Crash it!!

Co2 pressure is temp dependant. Ability to stay in suspension is pressure and temp dependant.
So when you raise temp or lower pressure (venting) it will come out of suspension

 

[HighVoltageMan!]

Co2 pressure is temp dependant. Ability to stay in suspension is pressure and temp dependant.
So when you raise temp or lower pressure (venting) it will come out of suspension

I'm assuming you are talking about co2. So, yes, as the temperature rises, the pressure needs to come up to maintain the same amount of co2 in solution. At @56F and 20psi I have about +2.5 volumes of co2. The beer is fully carb'd at that point.

Pressurize fermentation creates a secondary effect of co2 in solution. The co2 causes the yeast to behave differently, it will produce fewer esters and fewer higher alcohols. Lower temperatures and pressure can cause a double effect by lowering ester production even more due to temperature and dissolved co2. At 48F only 4-7psi is needed to get exceptionally clean fermentation. At 60F, it may need to be 15PSI to get similar results, but ester production will increase with temperature despite the co2 in solution. At least that's what I have seen.

 

[Minbari]

Ya, I was just talking about the behavior of the co2 itself.