Lagering al fresco.

[marinosr]

This topic has been covered in a hundred other threads, but all those threads are long on speculation and conventional wisdom, short on actual experimentation and results (with the notable exception of Revvy, whose posts were quite informative.)

Winter is fast approaching, and I want to try lagering in my outdoor shed during the months of December and January. I live in Durham, NC, which has appropriate mean temperatures for lagering during those months, with about a 20F diurnal difference between the highs and the lows. See this climate chart here: http://www.climate-zone.com/climate/united-states/north-carolina/raleigh/.

I plan on primary fermentation in a climate-controlled environment, followed by lagering outside in my shed, which roughly tracks the daily temperature fluctuations but more moderately due to being an enclosed space etc.

1. Has anyone out there tracked the daily temperature change of their lagering carboy under similar circumstances? Are there big changes, or does the high specific heat of the water adequately buffer against large temperature swings?

2. More importantly, has anyone had any bad experiences due to big temperature fluctuations, or has your beer turned out wonderfully?

Thanks for any experiences you can share!

 

[Ramitt]

If you can get power to your shed a fermwrap could help maintain more stable temps.

 

[Thunder_Chicken]

I have no information to offer, but I am planning a similar lager for this winter, utilizing my equipment room (~50F in winter) and lagering in my outbuilding (30-40 in winter).

With attention to the weather and your siting it should be quite doable - playing to the seasons is another completely valid way of achieving temperature control in my book. People made lagers before the invention of Fermwrap.

 

[WI_Wino]

Consider placing your carboy in a big tub of water. That would help maintain stable beer temperatures even as ambient air temps swing from night to day.

 

[harrymanback92]

Gonna follow this thread, as i have no ability to lager but have a pilsner planned this December.

I live in San Francisco so we get about 3 days where at night it dips below freezing. If it got to 20 degrees like in Durham, wouldn't the Carboy run a risk of freezing?

 

[WI_Wino]

OP was saying there is a 20 degree difference in daytime highs and night time lows. But yeah, there's a risk. It takes a lot of energy to freeze five gallons of beer though. If it's in an outbuilding, the temp swings are less. Even less of swings if you encase the carboy in an insulator like a sleeping bag or a tub full of water. Lots of options.

Oh and my real world experience is limited in the other direction, trying to keep cold keg beer cold in the middle of the summer. We do a canoe trip and paddle in quarter barrel (no portaging). We bring in a tub, ice, plastic, and sleeping bag. Keg goes in the tub, all the ice goes in around it, layer of plastic, sleeping bag, and another layer of plastic. The beer is still ice cold after several days of 90+ weather. So IMO if you are not at constant below freezing temperatures for days on end and inside a shelter I think will be fine.

 

[Thunder_Chicken]

The beer temperature will trend with the average of the daily highs and lows generally. I have a sour ferment going on in my shed in a 5 gallon plastic bucket, wrapped in a towel. The air temperatures in my shed have seen daily excursions from a low of 60 to a high of 80, and when I measured the beer temperature last it was 68F in the heat of the day. It probably varies +/- 2 or 3 degrees F around an average of 70F.

 

[RM-MN]

It seems to me that the point of lagering is to get the most yeast out of suspension to get the clearest, cleanest tasting beer. As your beer cools, more yeast drop out. When it warms up during the day, those yeast do not jump back into suspension so each time the beer temperature drops you drop yeast out. I'll be waiting for a report on this in about mid-December.

 

[zachattack]

Spend the $20 on the STC-1000 temperature controller and rig up something simple to heat it. It can even be a tub of water with an aquarium heater in it, or a small insulated box with a light bulb for a heater. It'll take you a few minutes to get everything put together and then you won't have to worry about it freezing.

 

[marinosr]

I realize that there are many engineered solutions to this particular question; I'm just trying to avoid them completely. This is why I want to know about the beer temperatures people have documented when subjecting their carboys to daily temperature swings. Thanks be to Thunder_Chicken and WI_Wino for their input.

Given that our average lows are around 28 at the coldest, and average temps are 38 at the coldest, I'm not really worried about the beer freezing unless there's a very bad cold spell, in which case I'd take extraordinary measures. STCs and Fermwraps are out, as the shed doesn't have electricity and I don't want to run power out there. If the temperature swings prove too great, I might consider the tub of water, but five gallons of beer is plenty of water in its own right, and I'm thinking that it will be sufficient to buffer the temperature changes.

What I'm more curious/worried about is if the temperature fluctuations will affect the taste of the finished brew. Lagering is partly about getting yeast to drop out, but it's also about controlling rates of specific yeast metabolic pathways as well as abiotic chemical changes, and I'm curious how the varying temperature will affect the flavors, if at all.


I'll definitely be trying this come December and I will report back results.

 

[Ramitt]

I originally read this as if you were fermenting a lager in the shed, was distracted and missed that you mentioned controlled fermentation. I can't imagine the temp swings will matter, at worst take a bit longer if they average higher.

 

[beersk]

If there's power in the shed, you could put the carboy in a tub of water and run an aquarium heater to keep a steady temperature.

 

[tagz]

My concern would be the sucking in of O2 and dust/bugs each time the temp swings. Depending on the degree of the temp swing, you could be sucking in air on a nightly basis.

 

[TyTanium]

I think you'll want to mitigate the swings to keep it at more or less the average temp.

For pretty cheap you could build yourself a box with plywood & polystyerene insulation board. And if you placed the beer in a tub of water inside the box I bet you'd be all set. You'd just have to monitor for freezing.

 

[marinosr]

I will not be building anything or plugging anything in. Thanks everybody for the building tips, but either this will work without building anything or I will do without lagers.

I simply want to know what kinds of temperature swings I can expect.


Tagz- you make a very good point. After the beer reaches ambient temperature, I might put a solid stopper on it during the hottest point of the day, provided that fermentation has stopped.

 

[JimRausch]

A month or so ago, there was a detailed discussion titled something like 'Help with Thermodynamics'. A heavy hitting discussion between a physicist and an engineer. But what us regular folks can take out of it is this:
A swamp cooler filled with water with your bucket sitting in that, will moderate the temps. of your beer within about 2* of the temp of the water jacket. So monitor the temp. of your swamp cooler water and adjust with heat or ice depending on where you want to be. An active fermentation, pumping out heat will strain that adjustment by another couple degrees possibly, but you will be close. OP said that his original fermentation can be done in a temp. controlled environment, so he'll be mostly lagering in the shed. IMO, based on me lagering in a swamp cooler(in a Maine late Fall-Winter, granted), it will work. Last year I lagered two in swamp coolers out in my garage. A couple mornings there was a thin skim of ice of the swamp cooler water, but the beer in the carboys never froze, and the fermstrip monitors stayed in the mid 30's. Tasty lagers too!

 

[marinosr]

Wow, that "Thermodynamics Help" thread is painful to read, not because of the physics but because of all the butthurt I'm sure somebody who knew how to program in MATLAB could have modeled this simple problem in 45 minutes, but that isn't me.

I'll see how the carboys fare in and out of a swamp cooler, and report back results.

 

[sfgoat]

Wow, that "Thermodynamics Help" thread is painful to read, not because of the physics but because of all the butthurt I'm sure somebody who knew how to program in MATLAB could have modeled this simple problem in 45 minutes, but that isn't me.

I'll see how the carboys fare in and out of a swamp cooler, and report back results.

Yeah those physicists can get pretty bitchy if somebody disagrees with them. Lol.

 

[marinosr]

Update on the lagering: I put a bock out in my shed last week after a three week primary fermentation, and I'm going to brew up a pilsener this week, so results will be forthcoming in a month or so. Tomorrow is supposed to be the coldest day in Durham since 1996, so we'll see if I can go to low temps without the carboys freezing.

 

[Thunder_Chicken]

I pitched s-23 on an extract helles on 12/14. Wort was 55F at pitch and the equipment room in which I placed the fermenter has been holding 47F very nicely. I'm going to let it go for a few more weeks, then rack and lager in my shed. So far, so good.

 

[JimRausch]

Here in Maine, it's been a sh***y winter- ice storm power outage for 5 days, snow up to the armpits, temps in the subzeros followed by 24 hours of rain, now a deep freeze again.
But..... through all this my 3 lagers have been very happy. The Vienna lager spent 6 weeks in a swamp cooler filled with water out in my garage. Thin skim of ice 1-2 days. Has been bottled since 2 weeks before Christmas and it's very nice.
My Soxtoberfest has been lagering for now going on 7 weeks. I just moved it to a warmer area in preparation for bottling sometime in the next week or so. There is probably 2 inches of solid ice in the bucket, but the beer in the carboy is not frozen. The dopplebock was racked for lagering a week ago and is solidly locked up in ice,although again, the beer is not frozen(of course that one is about 10%ABV).
So, Ghetto lagering is possible!

 

[Thunder_Chicken]

Just checked my helles - 3+ weeks in primary, at FG and tastes super clean. I brought it inside to warm up and don't detect any diacetyl. Tastes pretty damn good actually. I'm going to order the grains for a baltic porter, and when I brew that I'll rack my helles to a carboy to lager and will cool and pitch the porter on my yeast cake.