Author Topic: Quick lager fermentation questions  (Read 421 times)

Offline deidre888

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Quick lager fermentation questions
« on: June 26, 2018, 01:26:57 AM »
Greetings,
Here are the stats:
1. Pitched yeast nice large yeast starter (Wyeast Bohemian Lager) at 64 F on Monday 12:30 AM June 18.
2. Finished set up with the BrewJacket setup at 1:03 AM, set at 50F in brew room.
OG: Reading was 1.076
3. Fermentation activity already showing by 8 AM
4. Robust fermentation by 7 PM, 6/18

Next Gravity reading:   Monday, June 25, 2018, 7:40 PM
OG: Reading was 1.048

FG for this beer style (Bohemian Lager: Peroni clone) should be 1.012 (and yes, I'm aware my OG was a tad high for this tyle.)

QUESTION: Am I ready for my diacetyl rest? I feel like I should give it another week to get to 1.030. The yeast is doing a good job.

Thoughts?

Many thanks to anyone who takes a moment to repy,
D

Offline tommymorris

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Quick lager fermentation questions
« Reply #1 on: June 26, 2018, 01:35:36 AM »
Edit: never mind. I thought you were asking when to package.

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« Last Edit: June 26, 2018, 02:06:06 AM by tommymorris »

Offline Robert

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Re: Quick lager fermentation questions
« Reply #2 on: June 26, 2018, 01:41:02 AM »
My procedure is to let the ferment tell you when it's time for the diacetyl rest.   At some point (usually at or below 50% ADF) you'll notice that the activity (bubbling etc) starts to slow, and, if you can monitor it independently (not sure what clues the brew jacket gives you,) you'll see that the ferment is putting out less heat, and you need to reduce your cooling load to maintain the same temperature in the ferment. This tells you that the yeast has gone through primary (eating the easy simple sugars) and is transitioning to secondary fermentation (consuming more complex sugars and previous fermentation byproducts.)  At this point flavor is set, and you can let the temperature free rise to move things along.  This is more sensitive to the actual life of the yeast than using an arbitrary % attenuation, since you may not be able to accurately predict your final gravity (especially in a big beer.)  And remember, WY 2124 can run warm and still be clean!  Fear not.
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Offline deidre888

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Re: Quick lager fermentation questions
« Reply #3 on: June 26, 2018, 02:10:45 AM »
My procedure is to let the ferment tell you when it's time for the diacetyl rest.   At some point (usually at or below 50% ADF) you'll notice that the activity (bubbling etc) starts to slow, and, if you can monitor it independently (not sure what clues the brew jacket gives you,) you'll see that the ferment is putting out less heat, and you need to reduce your cooling load to maintain the same temperature in the ferment. This tells you that the yeast has gone through primary (eating the easy simple sugars) and is transitioning to secondary fermentation (consuming more complex sugars and previous fermentation byproducts.)  At this point flavor is set, and you can let the temperature free rise to move things along.  This is more sensitive to the actual life of the yeast than using an arbitrary % attenuation, since you may not be able to accurately predict your final gravity (especially in a big beer.)  And remember, WY 2124 can run warm and still be clean!  Fear not.

BrewJacket's pretty cool. I've been brewing since '94 and just never bothered with lagers, because I didn't have the space for a refrigeration unit and couldn't lager at temp. (new studies aside, regarding lagering at room temp.) When I bought the BrewJacket I primarily went about the business of continuing to make ales, but I'm finally getting around to lagers.

Annnnway, it does let's you know what the temp is at, as the yeast turn the malt into alcohol and the temp steadily drops. I use a refractometer to take my gravity readings, don't really depend on the bubble method any more.

I was going to check at week 5 for any D by doing the microwave heat test and if the beer was in great shape, I was going to push it through a 5 micron filter, keg and force carbonate it and then bottle it.

I'm clearly jumping the gun because I've got an entire other yeast starter for a Czec pils I'm dying to make, but just need to relax and have homebrew.

Thanks everyone for your help.

Cheers,
D


Offline Robert

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Re: Quick lager fermentation questions
« Reply #4 on: June 26, 2018, 02:20:41 AM »
^^^^
I control ambient temperature in the fermentation chamber while monitoring fermentation temperature in the thermowell in my fermenter, so I can see when the yeast is putting out less heat.   Also bubble rate is not that bad an indicator.  If you're regularly checking gravity, then you can see when the rate of drop in gravity slows, its just not as instant an indicator maybe.  But as soon as you have ANY indication that fermentation has peaked and is slowing, that's your cue to raise the temperature.  And again, WY 2124 is about as cooperative and forgiving a yeast, temperature-wise, as you'll find.   
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Offline pkrone

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Re: Quick lager fermentation questions
« Reply #5 on: June 26, 2018, 09:12:01 PM »
Lager fermentation procedures and opinions are quite varied.   Lots of different opinions about the right pitch temp, right ferm temp, whether you need a d-rest...

I like to pitch a huge amount of yeast at 48 and not do a d-rest.   If my fermentation has been sluggish (usually because I didn't pitch enough active yeast) I might raise the temp some to help the yeast finish. 

That's my 2 cents.   If your beer tastes good and yeast attenuates well, you're probably doing it right.
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Offline denny

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Re: Quick lager fermentation questions
« Reply #6 on: June 26, 2018, 10:08:33 PM »
Do you need a d rest?  4 days at 55, 3 days at 65, 3 days at 33 and it's ready to drink.  No diacetyl so no drest.
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Offline Steve Ruch

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Re: Quick lager fermentation questions
« Reply #7 on: June 27, 2018, 12:03:26 AM »
Do you need a d rest?  4 days at 55, 3 days at 65, 3 days at 33 and it's ready to drink.  No diacetyl so no drest.
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Offline Robert

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Re: Quick lager fermentation questions
« Reply #8 on: June 27, 2018, 12:22:31 AM »
Do you need a d rest?  4 days at 55, 3 days at 65, 3 days at 33 and it's ready to drink.  No diacetyl so no drest.
That is exactly what I do, but (see above) I like to observe the change in activity just to confirm the fermentation is going at the usual rate. It might be ready for a temperature rise a day faster even.  But with a healthy pitch of say 2124 or 34/70, yeah you can pretty safely assume that schedule, and fermentation will be complete in 7 days. Crash, clear, carb, prost.

EDIT the schedule will work even starting in the upper 40's to  just over 50° and rising to 55° over those 3-4 days, then rising to 65° before crashing on day 8. How pretty much all commercial breweries do it.
« Last Edit: June 27, 2018, 12:44:15 AM by Robert »
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Offline majorvices

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Re: Quick lager fermentation questions
« Reply #9 on: June 27, 2018, 02:03:55 AM »
The best way to check for diacetyl is to pull a sample, hold at 160 degrees for an hour (microwave a sample them put in hot water bath in cooler or use sous vide). After an hour, cool it down. If you smell or taste diacetyl you will need to diacetyl rest or krausen.

Personally, for lagers, I think it is best to pitch at (or a little above) the temp you intend to ferment at. So if you want to ferment at 50 cool down to that temp first then pitch.