How cold is too cold?

[worlddivides]

So the entire time I homebrewed in the US this wasn't remotely an issue. In fact, I had the opposite issue. When I first started homebrewing in 2014, I lived in the San Francisco Bay Area where it was mid 60s to mid 70s in the winter (15C to 26C or so) and was in upper 60s to upper 80s in the summer (20C to 30C or so). It occasionally got into the 90s in the summer and occasionally got into the mid to upper 50s in the winter, but it was mainly on the warm side of ale fermentation temps, so I had to be very careful about the fermenting wort getting too hot and never really worry about it getting too cold. I then moved to Michigan where, although it could get below zero outdoors, it was always the exact same temperature indoors due to central heating. Los Angeles was quite a bit warmer than San Francisco and I don't think it ever got below 60F (15C) in the time I lived there, but it did get over 40C (104F) a few times.

Now, though, I'm back in Tokyo and in a new house with three floors. It's November 8, so still fall, but I checked the temperature on the first floor around noon and it was 15.8C (60F), checked the temperature on the second floor and it was 20.9C (69F), and checked the temperature on the third floor and it was 22.4C (72F). I do everything brewing related on the first floor and I currently have a batch of brown ale fermenting, and the fermometer says it's currently 16C (61F), which is perfectly fine for the strain of English yeast.

But I bring this up because I'm getting the feeling that this means I will be incapable of fermenting any ale in the winter. If it's 15.8C (60F) on the first floor at noon on November 8, how cold is it going to be in mid-January? I know that some ale yeasts have lower temperature ranges that overlap with the upper range of lagers, but if it gets down to 4C or 2C outdoors at night, it's probably going to be around 10C (50F) or possibly even lower on the first floor of this house at that time.

It does make me think that maybe I should just ferment lagers in the winter time. And if the first floor is 13C or 14C, I can just add 2 liter bottles of ice to push the fermenter down to 9C or 10C, though I know some lagers go as high as 13C or even 14C.

This is something I've never had to deal with before, so I wanted to get some feedback.

 

[day_trippr]

Wait. Curve ball, I thought you were dealing with too warm, not potentially too cool.

Ok. When I first started brewing beer it happened to be a New England January, and I used an insulated cardboard box as a fermentation chamber, with a porcelain light bulb socket, a 40 watt incandescent bulb, and a $10 analog thermostat meant for baseboard electric heating.

It totally worked...

Cheers!

 

[worlddivides]

Wait. Curve ball, I thought you were dealing with too warm, not potentially too cool.

Ok. When I first started brewing beer it happened to be a New England January, and I used an insulated cardboard box as a fermentation chamber, with a porcelain light bulb socket, a 40 watt incandescent bulb, and a $10 analog thermostat meant for baseboard electric heating.

It totally worked...

Cheers!

When I lived in the US, I did have a FermWrap heater that I used for kettle souring and for strains that required higher than normal temps. That'd be perfect to have in the winter here.

I use a huge food delivery-type insulated bag (like the kinds used by Uber Eats, DoorDash, and so on) to keep the fermentation temp stable, and I'd really like something like a FermWrap.

The good thing is that there is a wall socket near where I keep the fermenter, so I should be able to use something electric for heat if necessary.

 

[day_trippr]

Bottom line, motivation will find a solution and it doesn't have to cost much at all...

Cheers!

 

[jrgtr42]

Personally I find my beers to be better if I ferment in the cooler range, lower 60s F, versus higher. It takes a bit longer, but I'm in no rush.

 

[worlddivides]

Personally I find my beers to be better if I ferment in the cooler range, lower 60s F, versus higher. It takes a bit longer, but I'm in no rush.

I'm not talking lower 60s. I'm talking lower 50s. I've fermented my last few batches at 59F to 65F using ice and so on, but with the weather getting colder and definitely getting much colder in December and January, the ambient temperature around the fermenter could be 50F or lower (the first floor was in the upper 50s when I woke up this morning and it's still November 8th).

 

[pdxal]

I'm not talking lower 60s. I'm talking lower 50s. I've fermented my last few batches at 59F to 65F using ice and so on, but with the weather getting colder and definitely getting much colder in December and January, the ambient temperature around the fermenter could be 50F or lower (the first floor was in the upper 50s when I woke up this morning and it's still November 8th).

Then that might mean that you have to ferment on 2nd or 3rd floor to maintain better temperatures in the winter time.

 

[worlddivides]

Fermenting on the second floor or the third floor would be a real pain (I've carried full fermenters up and down stairs before and it's not something I'd want to do again), so I'm going to see if I can get a FermWrap heater. And if I can't, then I'll try to improvise with something like what Day Trippr describes.

 

[Miraculix]

Nottingham will be fine with everything around 15 c and above, but that's the only English strain I know of that can go relatively low.

I would just use 3470 at any given temperature from 10c to 20c tbh. It makes a very fine beer at these temperatures. You might get a hint of an ale character at 20 c but still cleaner than for example Nottingham at the same temperature.

You wouldn't need to fiddle with the temperature when using 3470.

 

[worlddivides]

Nottingham will be fine with everything around 15 c and above, but that's the only English strain I know of that can go relatively low.

I would just use 3470 at any given temperature from 10c to 20c tbh. It makes a very fine beer at these temperatures. You might get a hint of an ale character at 20 c but still cleaner than for example Nottingham at the same temperature.

You wouldn't need to fiddle with the temperature when using 3470.

I've heard that some lager yeasts such as 34/70 and Bohemian Lager yeasts like 2124 can be brewed at temps from 8C to 20C or so with the character changing quite a bit across that range but being very drinkable at higher ranges. I think 34/70 is probably the best option if finding an efficient way to get the fermenter temp up to 16-18C is too much of a hassle. I believe the recommended temp for 34/70 is 9C to 15C, which would be perfectly within the range where I expect the first floor to be in the middle of winter (and I know a lot of people do ferment it at around 20C). It could be interesting to try to make an IPL, a Marzen, or even a Kolsch (the lowest I've seen some Kolsch yeasts go is around 12-13C).

 

[Miraculix]

I've heard that some lager yeasts such as 34/70 and Bohemian Lager yeasts like 2124 can be brewed at temps from 8C to 20C or so with the character changing quite a bit across that range but being very drinkable at higher ranges. I think 34/70 is probably the best option if finding an efficient way to get the fermenter temp up to 16-18C is too much of a hassle. I believe the recommended temp for 34/70 is 9C to 15C, which would be perfectly within the range where I expect the first floor to be in the middle of winter (and I know a lot of people do ferment it at around 20C). It could be interesting to try to make an IPL, a Marzen, or even a Kolsch (the lowest I've seen some Kolsch yeasts go is around 12-13C).

I've been fermenting 3470 as warm as 25 c without any issues except the slight ale character. It's not the maltiest lager yeast out there but it can really let the hops shine. And if you miss a bit of maltiness, it's easy to add like 10-20% Munich or similar. To me, it's the perfect work horse all-rounder.

 

[worlddivides]

I've been fermenting 3470 as warm as 25 c without any issues except the slight ale character. It's not the maltiest lager yeast out there but it can really let the hops shine. And if you miss a bit of maltiness, it's easy to add like 10-20% Munich or similar. To me, it's the perfect work horse all-rounder.

I've heard nothing but extensive praise for 34/70, but I was unaware its range was THAT huge. I knew it covered both typical lager and ale ranges, but that's a pretty huge range anyway. I'll keep that as my main option for winter fermenting, whether I can't get a FermWrap (or something similar) or I just decide I want to ferment lagers at ambient temps when the first floor is super cold.

 

[Bobby_M]

A temp controller and a low wattage wrap heater is perfect for your situation. Fermenting on the low end of the range is fine if you want low yeast character, but English and Belgian styles require some warmth. Even if you want to ferment near ambient temps, a few degrees of boost near the end of fermentation should be in everyone's process.

 

[MaxStout]

Another option for a low cost heating device is a seedling mat. They're typically around 20W or so, and can maintain warmth quite well if your fermenter is inside an insulated enclosure.

You don't necessarily need to wrap them around the FV; you can let them hang alongside it. A small computer fan can move air around for more consistent heat.

 

[mashdar]

1. Is the first floor heated, but on the same zone as upstairs? It's hard to predict how different areas on the same thermostat will behave without modeling or real world data. It could turn out that the first floor gets too hot, even.

2. I like the self-limiting heaters for beer, as they're less of a fire risk and also won't accidentally heat your beer to 110F. If not getting one of the fermenter wraps, look at reptile heaters. You wont be able to heat above 85F~, though, so might not work for a saison etc.

 

[kevin58]

If the ambient temperature where you brew is 15.8C (60F) then keep in mind that the act of fermentation increases the temp of the wort/beer by up 8° to 10°F. I ferment in my basement where the ambient temp is in the 50's F all year round. If I need to warm up the wort I just use an inexpensive FermWrap heating wrap around my fermenter.

 

[Steveruch]

You can brew your ale grainbill with lager yeast. I've brewed stout with lager yeast in January with good results.

 

[worlddivides]

1. Is the first floor heated, but on the same zone as upstairs? It's hard to predict how different areas on the same thermostat will behave without modeling or real world data. It could turn out that the first floor gets too hot, even.

2. I like the self-limiting heaters for beer, as they're less of a fire risk and also won't accidentally heat your beer to 110F. If not getting one of the fermenter wraps, look at reptile heaters. You wont be able to heat above 85F~, though, so might not work for a saison etc.

1. While places in the Midwest and East Coast like Michigan and New York use central heating, most places in the US (and the world) do not. As far as I'm aware, the only place in Japan that has central heating is the northern island of Hokkaido. Thus, thermostats don't really exist in houses or apartments in the Tokyo area. So the first floor is not heated. There is an air conditioner that I can turn on, but it really increases the electric bill. For example, my electric bill for August was around $250 just from cooling a single room or a single floor at a time throughout the month. I haven't heated the first floor yet this year, but even once I do, I don't expect it to have a huge effect on the fermenter's temperature since it's inside a closet on the first floor. Bringing it up to the second or third floor which are noticeably warmer would prevent the fermenter from getting too cold, but I would rather not lug a heavy fermenter up and down the stairs, so I'm planning to either use a method of heating the inside of the insulated bag or using lager yeast.

2. That's part of the reason why I'd like to get a FermWrap like I used to have, but I'm not sure whether it'll be possible or not. One thing I hadn't considered that could actually work pretty well is a small Japanese foot warmer/bed warmer. The amount of heat that it lets off is pretty small (with three settings: low, medium, and high that go up to a maximum of 60 watts. They can be had for about $10 to $30. The low setting typically is around 86F, the medium is around 113F, and the high is around 122F. That's just the temperature of the surface of the foot warmer which is typically covered in a soft cloth wrapping.

When I woke up this morning and checked the fermenter, there was zero airlock activity, though I imagine that's probably because it's S-04 and has been 5 days since I pitched the yeast (my last beer brewed with S-04 stopped having airlock activity after 3 days), but the temperature on the side of the fermenter says 14C (57F), which makes me worry whether S-04 has been made dormant before it could clean up the beer.

 

[worlddivides]

Another option for a low cost heating device is a seedling mat. They're typically around 20W or so, and can maintain warmth quite well if your fermenter is inside an insulated enclosure.

You don't necessarily need to wrap them around the FV; you can let them hang alongside it. A small computer fan can move air around for more consistent heat.

That's a really good idea. I just found a small one for about $15 on Amazon and a really big one for about $30 on Amazon. The small one is 20W and the big one is 45W. I'm guessing the 20W one would probably work better for an enclosed insulated bag like the one I use.

 

[MaxStout]

When I woke up this morning and checked the fermenter, there was zero airlock activity, though I imagine that's probably because it's S-04 and has been 5 days since I pitched the yeast (my last beer brewed with S-04 stopped having airlock activity after 3 days), but the temperature on the side of the fermenter says 14C (57F), which makes me worry whether S-04 has been made dormant before it could clean up the beer.

Warm it up to upper-60s, and rock the fermenter a bit to wake up the yeast. Leave it there for several days. It'll be fine.

 

[Bramling Cross]

If you have to choose, as a brewer, to be on the cool or warm side of things you always want to be on the cool side of things--unless you're dealing with those wierdo Kviek yeasts. Warming up a fermenter is a whole lot easier and cheaper than cooling a fermenter. Also, remember that the inside of your active fermentation is going to be a whole lot warmer than the ambient temperature. I expect that you'll find your ales improve in your cooler environment.

You're looking at this the wrong way around, you went from an okay brewing environment to an ideal environment.

 

[worlddivides]

Warm it up to upper-60s, and rock the fermenter a bit to wake up the yeast. Leave it there for several days. It'll be fine.

I ordered the $15 smaller 20W seedling mat and it should arrive tomorrow. Once it does, I plan to heat the fermenter up to around 68F or so, then rock the fermenter a bit. When the fermometer read 57F this morning, it was around 45F outside and had been 40F outside just a few hours earlier, so I do think that if temps get down into the 30s, I'm not going to be able to ferment ales without the seedling mat or similar. The convenient thing, though, is that this means I could ferment lagers in the winter time without using a temperature-controlled fridge. If the heat from fermentation increases, I can just use ice bottles to lower the temp back down into range like I do now. It'd just be lowering from 60F to 50F as opposed from 80F to 65F.

 

[worlddivides]

If you have to choose, as a brewer, to be on the cool or warm side of things you always want to be on the cool side of things--unless you're dealing with those wierdo Kviek yeasts. Warming up a fermenter is a whole lot easier and cheaper than cooling a fermenter. Also, remember that the inside of your active fermentation is going to be a whole lot warmer than the ambient temperature. I expect that you'll find your ales improve in your cooler environment.

You're looking at this the wrong way around, you went from an okay brewing environment to an ideal environment.

That's definitely true. When I lived in San Francisco, Southeast Michigan, and Los Angeles, I was able to control the temperatures pretty well within the ale fermentation range, but fermenting lagers was never even a possibility (unless we count the ones that ferment within ale fermentation temps). Now, though, it takes a lot less effort to lower the temperature and keep it there and I also have the option to ferment lagers.

The point about the temp of active fermentation is one of the reasons why I usually shoot for the fermometer to read around 62 to 64F when I'm fermenting, so even if the actual temperature is a little higher than that, it's only maybe 66F or 68F.

 

[Bramling Cross]

That's definitely true. When I lived in San Francisco, Southeast Michigan, and Los Angeles, I was able to control the temperatures pretty well within the ale fermentation range, but fermenting lagers was never even a possibility (unless we count the ones that ferment within ale fermentation temps). Now, though, it takes a lot less effort to lower the temperature and keep it there and I also have the option to ferment lagers.

The point about the temp of active fermentation is one of the reasons why I usually shoot for the fermometer to read around 62 to 64F when I'm fermenting, so even if the actual temperature is a little higher than that, it's only maybe 66F or 68F.

Seems reasonable to me. With my thermowells, which read the actual temperature inside the fermentation, I shoot for a pitch at 62-64F for US ale pitches and let them ride up to 68F, 72F back when I used to brew big stuff that I wanted to finish up quickly and neatly. For UK stuff I pitch at 66-68F and let them ride up to 68F-72F, depending upon how fruity I want it to get.

It sounds like you're in an ideal place. Rejoice!

 

[worlddivides]

Seems reasonable to me. With my thermowells, which read the actual temperature inside the fermentation, I shoot for a pitch at 62-64F for US ale pitches and let them ride up to 68F, 72F back when I used to brew big stuff that I wanted to finish up quickly and neatly. For UK stuff I pitch at 66-68F and let them ride up to 68F-72F, depending upon how fruity I want it to get.

It sounds like you're in an ideal place. Rejoice!

Years ago I used to ferment my UK ales around 68F to 73F, but lately I've been fermenting them around 60F to 66F, though the actual fermentation temperature might get as high as 68F-70F. I don't notice a huge difference, but the ales do seem just slightly less fruity/estery.

 

[Bramling Cross]

Oh, also remember that a 1.070 fermentation will get a whole lot hotter than a 1.45 fermentation. Even in your accommodating situation, you still might need cooling.

 

[Bramling Cross]

Years ago I used to ferment my UK ales around 68F to 73F, but lately I've been fermenting them around 60F to 66F, though the actual fermentation temperature might get as high as 68F-70F. I don't notice a huge difference, but the ales do seem just slightly less fruity/estery.

That makes sense. UK yeasts are every bit as complex as Belgian yeasts. As I've gotten better at UK brewing I've learned--been humbled by, really--the fact that no two UK strains are the same. Like Belgian yeasts, they're not generic. You need to pick a strain and really drill into it.

As brewers we often scoff at UK ales, they're so simple after all. But to brew them right? That takes a lot of work.

 

[worlddivides]

Oh, also remember that a 1.070 fermentation will get a whole lot hotter than a 1.45 fermentation. Even in your accommodating situation, you still might need cooling.

I also remember the first time I brewed with a Belgian Abbey ale yeast. The fermentation was so violent that it clogged up my airlock. I think the fermentation temperature was more than 10 degrees (F) higher than the ambient temperature, so I kept putting tons of ice in there to bring it down. That was back when I used glass carboys, and I remember thinking that the carboy could have exploded.

 

[worlddivides]

That makes sense. UK yeasts are every bit as complex as Belgian yeasts. As I've gotten better at UK brewing I've learned--been humbled by, really--the fact that no two UK strains are the same. Like Belgian yeasts, they're not generic. You need to pick a strain and really drill into it.

As brewers we often scoff at UK ales, they're so simple after all. But to brew them right? That takes a lot of work.

I think UK ales range from rather simple ones to incredibly complex ones. But, as you say, even the simple ones do take a lot of work to get them just right.

My girlfriend turned the heat on for the first floor, so I opened the closet and fully opened the huge food delivery bag I use for temperature control, then went on a walk. When I got back, the fermenter already read 16C (61F). This is only a temporary strategy, though, since the temperature gets especially low at night and the heat is off then (and it's off most days during the daytime too). The seedling mat arriving tomorrow should probably help with that. For the lager side, if the heat is on in the living room when fermenting a lager, I can just keep the closet door shut and the food delivery bag closed up (and optionally add ice bottles if necessary).

 

[hottpeper13]

So, what I want you to do is get in the shower at the temp you prefer. Now lower it by 10*, still feel good? No you don't. Just imagine a single cell organism without any fat to insulate. Oh ,we'll warm them up during the day, then lower at nite. NOT

The most important 2 things in the fermenter, 1- the proper temp for the yeast , 2- maintaining that temp.

 

[worlddivides]

So, what I want you to do is get in the shower at the temp you prefer. Now lower it by 10*, still feel good? No you don't. Just imagine a single cell organism without any fat to insulate. Oh ,we'll warm them up during the day, then lower at nite. NOT

The most important 2 things in the fermenter, 1- the proper temp for the yeast , 2- maintaining that temp.

Did you mean to post this in a different thread? Or did you just not read anything in this thread? Raising and lowering the temperature by 10 degrees? The issue I brought up is that the temperature gets too cold at night, bringing the fermenter down 1 to 2 degrees when it was already at the bottom range of what the yeast can handle. The fermenter was at 15 or 16C, then when I woke up in the morning it was 14C (a decrease of 1 to 2 degrees), which made me worry that it could make the yeast go dormant. I raised it back up to 16C (an increase of 2 degrees), which is where it's at now, though it might drop 1 to 2 degrees over the night and be back at 14C tomorrow morning. But once the seedling mat arrives, I should be able to raise the temperature to a higher temperature and keep it there. Not sure where you got this idea of "Oh, we'll warm them up during the day, then lower them at night. Oh, what a wonderful thing to do!" That's exactly what I want to AVOID.

 

[hottpeper13]

In reading between the lines you should have figured out I meant you to insulate the FV so there is no change, but i digress.

 

[worlddivides]

In reading between the lines you should have figured out I meant you to insulate the FV so there is no change, but i digress.

I should have figured out that you meant that I should do something I've been doing for more than 10 years?

 

[amber-ale]

Why don’t you just put it into two or three smaller fermentors that you can carry up to the warmer areas of your house? Then wrap them in some towels to insulate and stabilize temperature fluctuations.

Pick your beer style, yeast and fermentation location based on what temperature you consistently get in your house at a particular time of year.

 

[worlddivides]

Why don’t you just put it into two or three smaller fermentors that you can carry up to the warmer areas of your house? Then wrap them in some towels to insulate and stabilize temperature fluctuations.

Pick your beer style, yeast and fermentation location based on what temperature you consistently get in your house at a particular time of year.

I actually think that would have the opposite effect. The more volume of wort/beer I have, the more it takes for the temperature to change. If I took that volume and divided it by three, I would need to separately cool and heat three different fermenters. Plus, I don't think wrapping towels around them would stabilize temperature fluctuations any more than the insulation I already use (which is actually designed to keep the temperature stable). Plus, it'd mean buying three small fermenters, buying three fermentation cooler bags, and pitching yeast three separate times, along with managing the temperatures separately for three of them, then combining them all into the same keg.

The seedling mat arrived yesterday and I only had it on for a few hours, but it brought the temperature up to 18C, then I unplugged it. When I woke up this morning and checked 12 hours after I had unplugged it, the temperature had only dropped 1 degree to 17C, so this definitely seems like a very viable option. It might not go that well in the middle of winter, though, if the temperature outside the insulation is 10C or so, but I'll see what I can do.

 

[amber-ale]

That's great,!!
Solution found!