Ideas to keep fermenter warm

With coming winter upon us, no place in my house stays above 70 degrees. We're cheap bastards and keep the thermostat at no higher than 65. We don't even have the heat on at the moment and are waiting as long as we can until we turn it on. My basement stays a pretty constant temp at 65 or a little lower. After getting a FG (the first one I checked, my first batch I did no gravity measurements on) that seemed high, and I'm a bit concerned my yeasties are stopping before they're done.

I haven't had a problem with fermentation starting - it's happily going within less than 12 hours (pitch at 8PM, when I get up at 6AM things are happily bubbling away). I'm hoping a little shake of the fermenter now and then will keep the yeast going, I'm also hoping that once the heat gets turned on the that the heater will give the basement a couple degree boost in temp.

My other hope is that switching to safale S-04 will work better than the yeasts I used before (don't recall what they were but they weren't safale).

But anybody have a decently inexpensive idea on how to warm things up? I've seen suggestions for a reptile aquarium heater, but I'm concerned that will get things too warm, and a warm water bath isn't really practical since I don't have a sink in the basement.

Almost all of the LHBSs out there carry fermentation belts. This is an inexpensive device you slip around the outside of your primary. You just plug it in and it will help keep the temperatures up a few degrees compared with the ambient room temps. I used this in my basement for a few batches with great results. Now, I just heat a small fruit cellar in the basement used to ferment all of my batches, but the brewing belt works wonderfully!

rsmith179 said:

Almost all of the LHBSs out there carry fermentation belts.

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I had thought I'd seen that somewhere and couldn't find it and didn't know what to call it to search for it. Of course, I'm just blind and it had been staring me in the face. The one I'm looking at at the moment says the manufacturer doesn't recommend it for glass carboys (but it will fit). Which is fine for my plastic bucket, but I do use a carboy as a secondary. Is it just the manufacturer being extra safe? Anyone know how much of a temp jump it will give? I just need to go up a few degrees, but one review I read said it will bring it up 10 degrees (but he's got a much lower ambient temp so he might be seeing a larger gain), and that's getting too much on the warm side.

This still leaves me with the problem of the bottled stuff.

For the fermenter, I use a water bath in a cooler, and an aquarium heater. I use a floating thermometer.

But, 62-65 degrees is actually ideal, since you don't want to be above 70 degrees for fermentation anyway. This time of year is one of the best for me to make clean ales!

I don't know about bottles- just plenty of time at 60 degrees I'd guess. The yeast will still active, just slower.

I guess it's also helping that my pipeline has changed (for the moment) to do an additional week in primary. So I have 2-2-3. Maybe I'll just buy the belt and use it a little bit every day to give a little temp boost to the primary.

I have also seen those warnings from the makers of the brew belt regarding glass carboys. At first I stuck to those warnings, making sure not to use them on my carboys. Last winter, I did end up using this on a glass carboy and had no negative impact. I would imagine that they are concerned with the heat making the glass fragile, increasing the odds of cracking, but I have never had an issue with it.

YooperBrew said:

But, 62-65 degrees is actually ideal, since you don't want to be above 70 degrees for fermentation anyway. This time of year is one of the best for me to make clean ales!

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This is where I get confused because I keep seeing conflicting information. Some people say not to go above 70 and low 60s is best, others say high 60's to mid 70s is best, the brew belt thing says 75 is ideal, and my yeast package says 57-75.

I use a pharmacy purchased heating pad set to low. If I didn't already own this I would have gone with the brew belt.

65F is fine. I set my ferm chamber at 60-62F for ales and have fermented notty at 58F. Don't bother with a heat belt.

RCCOLA said:

65F is fine. I set my ferm chamber at 60-62F for ales and have fermented notty at 58F. Don't bother with a heat belt.

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I'm starting to think that myself actually after doing some more research. The FG on my last batch just unnerved me a bit, much because the beer itself didn't turn out how I had expected it to. I was looking for a more red color and a not as malty. Didn't taste bad or even taste off but it just wasn't what I had expected.

For really cold weather, when my basement is below optimum fermentation temps, I wrap my primaries with towels and put them above the basement floor (small shelving unit) next to the water heaters. This helps keep them in the prime temp range.

A string of christmas lights and a blanked could be fashioned into a carboy warmer.

bonzombiekitty said:

This is where I get confused because I keep seeing conflicting information. Some people say not to go above 70 and low 60s is best, others say high 60's to mid 70s is best, the brew belt thing says 75 is ideal, and my yeast package says 57-75.

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If your yeast says 59-75, 75 is the upper limit. My experience is that unless you want esters (fruity, including banana), you want to stay in the middle or low end of the yeast strain's ideal temperatures.

Also, keep in mind that if your room is 70 degrees, the heat of the fermentation might make the brew inside be 78-80 degrees! I ferment most of my ales in a room that is 60 degrees, in order to be in the 64 degree area.

For fun, try fermenting a blonde ale at 57-59 degrees. I bet you'll have a lager-like, "clean" ale. Ferment the same beer at 75 degrees, to see the difference! It'll be a big difference.

The aquarium heater trick works really well. You don't need a sink- I use a bucket a bit larger than my carboy, and it only takes a few gallons to fill it. You do have to watch for evaporation, because the heater doesn't go on and off by temp, so if the water level gets too low it will heat it up more. I've held batches at 63 before with no variation over three weeks.

I wrap mine in a sleeping bag opening it up a little to adjust the heat, has worked well to get to my FG and keep my temp close to 68 degrees.

YooperBrew said:

For the fermenter, I use a water bath in a cooler, and an aquarium heater. I use a floating thermometer.

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I agree as well. If you are lucky enough to have a slightly cool fermentation area, you can have perfect and adjustable fermentation control for about $20.

The nice thing about aquarium heaters is that they are very inexpensive yet provide very precise temperature control (just like yeast, temperature fluctuations are hard on fish, so even the cheapest aquarium heater will have precise temp control).

Slap one or two heaters in a big plastic bin of water, and there you have a fermentation chamber where the temperature will sit at whatever you dial it in to. Better yet, all that water provides plenty of thermal mass, so any heat generated from your fermentation is buffered, further preventing big temperature swings. There is no better way to achieve a consistent fermentation temp.

Oh yeah, pet stores also sell those floating thermometers for about $2 and they are far more accurate than the cheap thermometers you will often find at the LHBS. So, total system is aquarium heater ($12), plastic rubbermaid container ($6), floating thermometer ($2) = $20. Far superior and much less expensive than other methods I have tried, in brew belts, temperature controlled fridges, etc.

Pic in action:

ooooooooooo. I like FlyGuy's idea. Might not be totally useful for what I'm making at the moment, but I think that'll work really well for things that I will need more temp control for.

Let me see if I understand yeast enough.
The temperature range is a guideline to know where a particular yeast is comfortable working. Yeast works slower at lower temps tend to yield cleaner flavors and faster at higher temps with a potential for off flavors.
The yeast working causes single digit increase in fermenter temp over ambient temp therefore if your room/chamber is 70 degrees, you are flirting with off flavors.
The closet where I ferment is, and has been, 60 degrees for days so I can expect my fermentation temperature to be 64-66 until active ferm is over. Then the temp will be closer to, if not actually, closet temperature where things will plug along nicely, if a little slower than if it were 65.
So I won't worry, yes?

FlyGuy said:

Pic in action:

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OMG, that is beautiful.

I bought a $20 space heater plugged into a Ranco controler. I put a bungie cord around my fermenter and sandwhiched the thermistor between the glass and a towel, holding it in place with the bungie cord. I wrap a blanket around the fermenter (sorta distributes the heat a bit). I then set the fan up 2-3' away and aim it at the fermenter. I make sure the thermocouple is on the opposite side of the fermenter from the fan. Using this method I was able to keep a saison at 78 F and the rest of my ales at 67 F.

This works well durring the begining of fermentation, bc the yeast keep all of the liquid churning.

Although not ideal, this worked really well last year. Right now I am constructing a multichamber fermentation closet, hopefully that will regulate the temperature even better.

Try placing the fermenter near the furnace or the water heater.

Place a therm strip near the fermenter to see how much heat is radiated...too warm=too close, not warm enough= too far away.

I like to start my ale fermentations at the low end of the range for 2 days and then slowly ramp them up to the upper end of the range by day 7. I do the same with lagers, but more slowly over about 10 days. This helps with diacetyl in both and makes sure the yeast don't floc out too early.

The aquarium heater is a great solution for 1 or 2 carboys. After that you need to start thinking of a makeshift isolation chamber, a cheap $9 walmart space heater, and a temp controller. The enclosure can be as simple as a table with a blanket draped over it (remember building forts as a kid?). Just keep the heater away from it.

Bobby, Yup that's what I've done in the past.

I am basically making an isolation chamber this year. With either a space heater or lightbulbs in a box vented into the chamber. I think I saw someone else do that on this forum before.