Author Topic: Stuck lager (couple of points sg) need advice.  (Read 5631 times)

Offline Nick_D

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Re: Stuck lager (couple of points sg) need advice.
« Reply #75 on: April 21, 2016, 04:05:15 AM »
1.012 is pretty decently fermented out for most lagers, though if mashed low enough, some of mine are in the 1.008-1.010 range.  There's only so much the yeast can do with the wort given them, right?

It sounds like you did what you could and it likely will be a wonderful lager beer.

Thanks, yeah, 1.012 isn't totally out of style for a helles, and I understand they often intentionally stop slightly short of full attenuation for the style (like, maybe half a point).

I have been continuing my research into the traditional cold lager fermentation schedule, and I am confident to give it another try.

Here is a chart showing lager schedules. left to right is duration days, vertical scale is temperature in degrees Celsius (sorry, from Australia).  The black line is what I did, before I raised the temp to fix the attenuation issue. Red and green lines are fermentation schedules I found from various sources. The green is actually the schedule used by a German brewpub on their Pils.  It is easy to see I cooled far too quickly when approaching near freezing.

The beer is cleaning up very well, and I am almost ready to start lowering the temp again!

« Last Edit: April 21, 2016, 04:21:16 AM by Nick_D »

Offline hopfenundmalz

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Re: Stuck lager (couple of points sg) need advice.
« Reply #76 on: April 21, 2016, 11:43:10 AM »
Those profiles have a time at 3C, which caught my attention. Last November I was in Germany and toured a low tech traditional brewery in Neiderbayern on a brew day. The lagering cellar was tunneled into the rocks, and was at 3C (year round according to the assistant Brewer). Just a coincidence? Maybe.
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Offline beersk

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Re: Stuck lager (couple of points sg) need advice.
« Reply #77 on: April 22, 2016, 02:03:57 PM »
Those profiles have a time at 3C, which caught my attention. Last November I was in Germany and toured a low tech traditional brewery in Neiderbayern on a brew day. The lagering cellar was tunneled into the rocks, and was at 3C (year round according to the assistant Brewer). Just a coincidence? Maybe.
It's interesting that lager yeast will still work at that low of a temperature. The schedule I've done on the last couple beers is 6 days at 48-50F, raise to 60F for a day, then drop 5F per day until it's down to 40F. Haven't tasted the final results yet, but would kind of like to get to a point where I can just keep it cold and not do the warmer rest and gradually lower from fermentation temp to cold temps.

Offline brewinhard

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Re: Stuck lager (couple of points sg) need advice.
« Reply #78 on: April 22, 2016, 02:08:04 PM »
Those profiles have a time at 3C, which caught my attention. Last November I was in Germany and toured a low tech traditional brewery in Neiderbayern on a brew day. The lagering cellar was tunneled into the rocks, and was at 3C (year round according to the assistant Brewer). Just a coincidence? Maybe.
but would kind of like to get to a point where I can just keep it cold and not do the warmer rest and gradually lower from fermentation temp to cold temps.

I have not found any need to gradually lower the fermentation temps to cold temps for putting out good lagers. After I run a proper diacetyl rest, I cold crash overnight and keg the next day.


Offline beersk

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Re: Stuck lager (couple of points sg) need advice.
« Reply #79 on: April 22, 2016, 02:09:31 PM »
Those profiles have a time at 3C, which caught my attention. Last November I was in Germany and toured a low tech traditional brewery in Neiderbayern on a brew day. The lagering cellar was tunneled into the rocks, and was at 3C (year round according to the assistant Brewer). Just a coincidence? Maybe.
but would kind of like to get to a point where I can just keep it cold and not do the warmer rest and gradually lower from fermentation temp to cold temps.

I have not found any need to gradually lower the fermentation temps to cold temps for putting out good lagers. After I run a proper diacetyl rest, I cold crash overnight and keg the next day.


The real reason I've been doing it is so it doesn't suck as much starsan back through my airlock. But I also believe there is something to gradually dropping the temp versus a straight-up crash. I don't know though...it's easy enough and I got the time.

Offline brewinhard

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Re: Stuck lager (couple of points sg) need advice.
« Reply #80 on: April 22, 2016, 02:22:59 PM »
I always remove the airlock and just place saran wrap/foil over the carboy opening while cold crashing. Only because as the negative pressure is created inside the carboy from cooling, it pulls outside air into the carboy through the airlock (and star san sometimes) as it bubbles backwards.

Offline narcout

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Re: Stuck lager (couple of points sg) need advice.
« Reply #81 on: April 22, 2016, 05:10:08 PM »
But I also believe there is something to gradually dropping the temp versus a straight-up crash. I don't know though...it's easy enough and I got the time.

My understanding of traditional lager brewing is that the beer is cooled slowly towards the end of fermentation to avoid shocking the yeast.  When there is still a small portion of fermentable extract remaining, the beer is racked into secondary, sealed with a pressure relief valve (to allow for natural carbonation), and slowly cooled further while the yeast continues working.

I guess cooling slowly is of less importance when one is allowing fermentation to complete during a higher temperature diacetyl rest and then racking to kegs for force carbing. 

Whether there are flavor differences between the two methods, I cannot say.  I would like to give the first method a try sometime though.
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Offline HoosierBrew

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Re: Stuck lager (couple of points sg) need advice.
« Reply #82 on: April 22, 2016, 06:10:54 PM »
I have not found any need to gradually lower the fermentation temps to cold temps for putting out good lagers. After I run a proper diacetyl rest, I cold crash overnight and keg the next day.


+1.  I cold crash in the keg after d rest and don't notice any issues at all.
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Offline blair.streit

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Re: Stuck lager (couple of points sg) need advice.
« Reply #83 on: April 22, 2016, 10:42:42 PM »
I have not found any need to gradually lower the fermentation temps to cold temps for putting out good lagers. After I run a proper diacetyl rest, I cold crash overnight and keg the next day.


+1.  I cold crash in the keg after d rest and don't notice any issues at all.
Yeah Sacc. may have to comment on the actual biological consequences. However from my layman's point of view, if the yeast are finished with their work, as long as you don't freeze them and explode the contents all over your beer then cooling fast shouldn't matter.

Offline hopfenundmalz

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Re: Stuck lager (couple of points sg) need advice.
« Reply #84 on: April 22, 2016, 11:59:40 PM »
Supposedly the yeast can give off undesirable flavors if stressed by too rapid cooling. I have not experienced this. I might go down 5-7 degrees per day. Oh, and I lager at -1C.
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Offline wobdee

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Re: Stuck lager (couple of points sg) need advice.
« Reply #85 on: April 23, 2016, 12:55:22 AM »
I read somewhere that dropping temps too fast causes the yeast to release an enzyme that can hurt foam and head retention.

Offline blair.streit

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Re: Stuck lager (couple of points sg) need advice.
« Reply #86 on: April 23, 2016, 01:02:22 AM »
Supposedly the yeast can give off undesirable flavors if stressed by too rapid cooling. I have not experienced this. I might go down 5-7 degrees per day. Oh, and I lager at -1C.
Yeah, I've heard read that the "heat stress" we hear about is rally from quick heating or cooling.

I've heard a lot about this in anecdotal terms (i.e. "I cool at X per Y and never have problems"). So far I haven't come across a text or trusted source with data on how fast is too fast.

With that in mind I tend to play it a bit conservative in this regard. In many ways, as homebrewers we have an advantage because many things that are issues at a commercial scale don't seem to be at our scale (i.e. we don't have to worry about hydrostatic pressure causing quick degradation in yeast health). On the other hand, in some cases we can change the temperature of our beer more rapidly than most commercial brewers. I sometimes wonder if that could cause is problems if we don't understand the practical implications.