Temperature maintenance during fermentation

[124Spider]

Hi,

We have air conditioning in our house, but don't use it until the house gets above, say, 78 degrees F.

I'm brewing a batch now that's supposed to ferment at 64-72 F.

Right now, it's cold outside, so that's not a problem; but some time during the next three weeks, it likely will get warm, and I would very much rather not spend a fortune keeping my house cold just for beer.

How critical is this temperature regulation?

Thanks.

Mark

 

[ICWiener]

How critical is this temperature regulation?

Very. You can find a thousand threads on the topic and just about every one of them will tell you that temp. control plays a vital role in the quality of your beer.

I used to do what you're doing, and in the summer my beers would get nasty fusel alcohol flavors to them. I learned that 75-78 was way too hot to be fermenting beer. Get yourself a plastic tub, fill it with water and put the carboy/bucket of beer in there. Add blocks of ice if the temp gets too high.

 

[Jarov]

I have the setup ICWiener proposed, its fantastic. I've got numerous sizes of frozen bottles in the freezer, ranging from a 20 oz bottle to a gallon jug. Whenever the temp gets too warm, in goes a bottle.

 

[kevo342]

I'm working on converting my mini fridge into a fermentation chamber. After rearranging the freezer shelf, my 6 gallon better bottle with a blow off tube fits in there. Now I just need to fashion a shelf to make the whole bottom level with the hump for the compressor, and get a good temperature control system and I'll be ready to go!

 

[124Spider]

Ok, thanks. A/C may be pressed into service, since I can't be there all day loading ice into a bucket if it gets warm.

 

[ICWiener]

A/C may be pressed into service, since I can't be there all day loading ice into a bucket if it gets warm.

You don't need to do that. The water acts as an insulator/buffer. It's not going to fluctuate wildly. Just chuck a few frozen water bottles in there every so often. You should be fine. Otherwise you'll go broke running your AC at 66F for 24 hours a day.

 

[grem135]

I just put frozen bottles in before work, after work, before bed. every 8 hours +/- an hour or so. I have 20 oz, 1 ltr and 64 oz bottles. 20 oz worked great all winter and used the 1 litter or 20oz as needed on my last batch.

 

[funnycreature]

My single best investment today: https://www.homebrewtalk.com/f39/extra-fridge-temp-control-question-399794/#post5034475

I hooked up my wine cooler to it since its own control was worthless. It's been great since!

 

[Rbeckett]

STC-1000 and a junk yard fridge... Grand total of 84 bucks invested. I can control the temp with in 1/2 degree Centrigrade. I do my boil, use my Immersion chiller, and move everything straight into the keezer. Set the temp for about 18 C, and leave it the heck alone. After three weeks, I check the grav on three conseci=utive days and if stable I bottle and put the bottles right back in the keezer. After 3 weeks at 18, then I drop the temp to around 5 C and allow the brew to cool completely and serve. Works perfectly and is way cheaper than the electric bill for cooling the house for just one month. Look into it, I am very happy with my rig and if the freezer dies, I can get another off of Craigslist for another 50 bucks....

Wheelchair Bob

 

[124Spider]

I'm not really interested in something as large, or potentially leaky, as a junkyard fridge. But the idea of buying a relatively inexpensive, smaller fridge, and regulating it with an STC-1000 has appeal.

How much work/how complicated is it to adapt the STC-1000 to a fridge or freezer?

Thanks.

Mark

 

[ICWiener]

How much work/how complicated is it to adapt the STC-1000 to a fridge or freezer?

How handy are you with wiring up electronics? I'm not, like at all, and I can't speak for the STC, but I bought a Ranco 21100 and I was able to wire it up no problem. If you're serious about the hobby long term, the fridge is a good way to go. You throw your beer in there, set, and forget it. The tub of water/ice is a good, quick low tech solution, but if you've got the money and space the fridge/chest freezer can't be beat.

 

[124Spider]

I'm handy, just lazy (complicated projects go unfinished, but I can change the motor in my car).

A fridge does sound like the only way to go.

 

[BigFloyd]

I'm not really interested in something as large, or potentially leaky, as a junkyard fridge. But the idea of buying a relatively inexpensive, smaller fridge, and regulating it with an STC-1000 has appeal.

How much work/how complicated is it to adapt the STC-1000 to a fridge or freezer?

Thanks.

Mark

It's pretty darn easy. I currently have three (keezer, fermenter fridge and lagering/cold crash freezer).

The STC-1000 is a dual temperature controller. You wire it into a standard 2-plug outlet that you mount in some kind of project box (either homemade or bought at Radio Shack). One (cool) outlet is for the freezer/fridge. Into the other (warm) outlet, you plug some kind of small heater and then put that heater inside the freezer.

Set the target temp (in Celsius) on the STC-1000. Set the tolerance (default is +/-0.5*C). When the temp (as read by the sensor) climbs 0.5*C above the target, it powers up the cool outlet and keeps it energized until the temp drops to the target and then turns it off. Likewise with the warm outlet if it gets 0.5*C too cool. You tape the sensor on the side of the fermenter and place some kind of insulation like bubble wrap over top of it so that it reads the bucket temp and not the air.

https://www.homebrewtalk.com/f51/ebay-fish-tank-controller-build-using-wal-mart-parts-261506/


https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/



http://brewstands.com/fermentation-heater.html

Hope this helps.

 

[ICWiener]

A fridge does sound like the only way to go.

I agree. Just remember that if you get a freezer it helps to put in something to take care of excess moisture, like Damp Rid.

Once you get it rolling, it's awesome. Here's my setup:

 

[124Spider]

I see how the STC-1000 works, but I wonder if that is just a recipe for, at the least, high energy costs, or, worse, failure of the fridge. It seems to me that introducing a heater into the fridge/freezer will cause the fridge/freezer to run all the time, and the heater to run a lot of the time; the fridge/freezer will not like running all the time.

Is there any reason (assuming the right size can be found, and I don't mind the cost) why I can't use a wine fridge? Is there any other ready-made solution?

Thanks.

Mark

 

[BigFloyd]

I see how the STC-1000 works, but I wonder if that is just a recipe for, at the least, high energy costs, or, worse, failure of the fridge. It seems to me that introducing a heater into the fridge/freezer will cause the fridge/freezer to run all the time, and the heater to run a lot of the time; the fridge/freezer will not like running all the time.

No. That's an understandable misconception, but not at all accurate.

The heater only goes on when the temp in the fridge/freezer gets 0.5*C below where you had set it to maintain. They never ever run at the same time or even close. The only time I've needed the heater is when I used a chest freezer that was in the garage during winter. I was fermenting ales in the low-mid 60's while the garage temp was in the 30's-40's. The freezer never had to run and the heater only kicked on infrequently to maintain temps.

Most of the year, I have nothing plugged into the "heat" part of the outlet box for the fermenter chamber. The STC-1000 units on my keezer and my lagering chamber (both set in the 30's) have no heater involved at all.

 

[124Spider]

No. That's an understandable misconception, but not at all accurate.

The heater only goes on when the temp in the fridge/freezer gets 0.5*C below where you had set it to maintain. They never ever run at the same time or even close. The only time I've needed the heater is when I used a chest freezer that was in the garage during winter. I was fermenting ales in the low-mid 60's while the garage temp was in the 30's-40's. The freezer never had to run and the heater only kicked on infrequently to maintain temps.

Most of the year, I have nothing plugged into the "heat" part of the outlet box for the fermenter chamber. The STC-1000 units on my keezer and my lagering chamber (both set in the 30's) have no heater involved at all.

Ok, I'll bite.

If it's always hot outside, and always hot inside (not an unusual event in Tyler, Texas, and it happens even here in Seattle), how do you keep your freezer at 65 without having it plugged in to cool? I understand that, if I were to keep it in the garage in the winter, I would only need a heater, but I don't understand how that would work when the ambient temperature is above what you want your beer fermenting at.

It appears to me (and I'm happy to be shown to be wrong) that in the summer, you'll have to have the fridge on, to keep it below ambient, but that, because a normal fridge can't be set to much warmer than 40, you must have a heater in there, to keep it at 65. But this will, by definition, cause the fridge to kick in. All the time in warm weather.

 

[kh54s10]

Ok, I'll bite.

If it's always hot outside, and always hot inside (not an unusual event in Tyler, Texas, and it happens even here in Seattle), how do you keep your freezer at 65 without having it plugged in to cool? I understand that, if I were to keep it in the garage in the winter, I would only need a heater, but I don't understand how that would work when the ambient temperature is above what you want your beer fermenting at.

It appears to me (and I'm happy to be shown to be wrong) that in the summer, you'll have to have the fridge on, to keep it below ambient, but that, because a normal fridge can't be set to much warmer than 40, you must have a heater in there, to keep it at 65. But this will, by definition, cause the fridge to kick in. All the time in warm weather.

I cool year round since my system is in my basement "man cave". I made a fermentation chamber using scrap plywood, 2x4's and some 2" foam insulation. I use a Johnson A419 controller and and a mini fridge in one end for the cooling. It works like a charm.

 

[124Spider]

Yeah, a basement, especially in a place that's normally not too hot (like Seattle or RI) would be perfect. Unfortunately, I don't have one.

I suspect that a wine refrigerator, which will cool to 55-70, and large enough for my fermentation bucket, may be the best answer for me.

 

[hops2it]

I use a Johnson Controller A419 as well and there's no doubt the beer got better immediately. In fact, I quit brewing for awhile when my freezer (old one to start with) crapped out until I recently replaced it. If I can't temp control after having done so, I'll skip it altogether. I feel it's that important for a high quality product.

I've never found a need for a heater personally. My freezer tends to be around 66-70 inside without cooling depending on time of year and nothing I do requires a higher temp than that. If it did, I'd just remove my bucket and place it on one of the 3 floors in my house (including basement) which all increase in their temp as I go upward.

 

[DaNewf]

My setup:

5 cubic foot chest freezer (only fits one full size fermenter )
Heat belt
STC-1000 temperature controller

Heat belt goes on the fermenter.
Fermenter goes in the freezer.
Freezer plugs into STC-1000 cold side.
Heat belt plugs into STC-1000 hot side.
STC-1000 temperature probe gets strapped to the fermenter with sleeping pad foam and bungee cords.
STC-1000 gets set to 18C +/- 0.5C and the cooling delay set to 10 minutes.

Close the freezer and forget for three weeks. The STC-1000 is reading the actual temperature of the fermenter and cycles either the freezer or heat belt as required to maintain 18C.

I use this setup year round. In the dead of winter the heat belt does most of the work. In the hot part of the summer the freezer is doing most of it.

 

[grem135]

Ok, I'll bite.

If it's always hot outside, and always hot inside (not an unusual event in Tyler, Texas, and it happens even here in Seattle), how do you keep your freezer at 65 without having it plugged in to cool? I understand that, if I were to keep it in the garage in the winter, I would only need a heater, but I don't understand how that would work when the ambient temperature is above what you want your beer fermenting at.

It appears to me (and I'm happy to be shown to be wrong) that in the summer, you'll have to have the fridge on, to keep it below ambient, but that, because a normal fridge can't be set to much warmer than 40, you must have a heater in there, to keep it at 65. But this will, by definition, cause the fridge to kick in. All the time in warm weather.

You have the fridge plugged into the cool side of the controller and it turns the fridge on or off as needed, it does not matter that the fridge thermostat is set at as long as it is set cooler than you need.

 

[rgarry]

My understanding is the first 3-4 days are critical. If you are cold right now and finish fermenting that temps in the low to mid 70's won't effect flavor as much as it does during the first 3 days. I live in Florida and we deal with this all the time. Sure I use a fermentation chamber and noticed the difference when I switched but it wasn't drastic. I used one of those cool brew coolers and filled with gallons of from water. It worked fine and obviously is cheaper than a fermentation chamber. I know I will get bashed for this but I think you will be fine.

 

[Rockindaddy]

I just bought a chest freezer off craigslist for $60.00 and bought the STC-1000 from ebay. With the STC-1000, project box, plug & cover I spent about $35.00. I just use a light bulb for my heat source and it works perfect. I'm in New Mexico and my wife is from Brazil, so she likes the house on the warm side. There was nowhere that I could ferment beer in my house and get the right temperature. This was a great solution for me. It keeps the temperature right where I need it. Just set the temperature you want close the lid and walk away!

 

[BigFloyd]

Ok, I'll bite.

If it's always hot outside, and always hot inside (not an unusual event in Tyler, Texas, and it happens even here in Seattle), how do you keep your freezer at 65 without having it plugged in to cool? I understand that, if I were to keep it in the garage in the winter, I would only need a heater, but I don't understand how that would work when the ambient temperature is above what you want your beer fermenting at.

It appears to me (and I'm happy to be shown to be wrong) that in the summer, you'll have to have the fridge on, to keep it below ambient, but that, because a normal fridge can't be set to much warmer than 40, you must have a heater in there, to keep it at 65. But this will, by definition, cause the fridge to kick in. All the time in warm weather.

A controller like the STC-1000 takes the fridge/freezer thermostat out of the equation. When you're cooling in the warmer months, the controller simply turns the fridge on and off as needed to keep the temp at the set value (+/- the set tolerance). It can be a number way above the max of the fridge thermostat. No heater required.

For example, I have a Vienna/Amarillo SMASH fermenting now at 15*C (59*F). My tolerance is set at 0.7*C. When the temp inside the fridge climbs to 15.7*C, the STC-1000 powers the fridge outlet and keeps it powered until the temp drops back down to 15*C at which time it turns off the fridge power. My fridge thermostat is set on coldest.

 

[124Spider]

Ok, I see how it works. Thanks!

I've decided:

I have bought a 5.1 cubic foot chest freezer, and an STC-1000. The STC-1000 is supposed to be delivered on Friday, and I'll get a heating strap for my fermenter before then from our local brewing store.

Thanks very much!

 

[BigFloyd]

Ok, I see how it works. Thanks!

No worries. You're certainly not the first person to have those sorts of questions about how the controller and the fridge/freezer work together.

By far the best $100 (out of the many hundreds) I've spent on brew gear.

 

[ICWiener]

I have bought a 5.1 cubic foot chest freezer, and an STC-1000. The STC-1000 is supposed to be delivered on Friday, and I'll get a heating strap for my fermenter before then from our local brewing store.

Nice! You've made a wise decision.

Bottom line is that if you want to make great beer, you have to control those fermentation temps. It's a non-starter.

 

[rgarry]

You can also use it to cold crash.

 

[BigFloyd]

Ok, I see how it works. Thanks!

I've decided:

I have bought a 5.1 cubic foot chest freezer, and an STC-1000. The STC-1000 is supposed to be delivered on Friday, and I'll get a heating strap for my fermenter before then from our local brewing store.

Thanks very much!

Good call. You're gonna love it.

Now you can do stuff like stepped-up ale ferments where you start at the low end of the optimal range for the yeast being used, keep it there 5-7 days, and then bring it up 4-6*F to finish and clean up.

You can properly do lagers as well, but be mindful of the fact that they can tie up your chest freezer for several weeks. Best to brew a couple lager batches back-to-back and then ferment/d-rest/cold crash/lager them together if possible.

 

[rgarry]

Good call. You're gonna love it.

Now you can do stuff like stepped-up ale ferments where you start at the low end of the optimal range for the yeast being used, keep it there 5-7 days, and then bring it up 4-6*F to finish and clean up.

You can properly do lagers as well, but be mindful of the fact that they can tie up your chest freezer for several weeks. Best to brew a couple lager batches back-to-back and then ferment/d-rest/cold crash/lager them together if possible.

This is a man who talks from experience. Sometimes trying to coordinate everything is crazy. I use it to ferment, cold crash and when I get close to needing another keg, I chuck it in and carbonate so its already when the kegarator needs a new keg. Obviously, they all require different temps.

 

[124Spider]

What's "cold crash"?

 

[ICWiener]

Cold crashing is dropping the temp. in your fermenter down to the 33-39F range for a couple of days after fermentation is complete. It pulls a lot of yeast out of suspension, clarifies your beer. If you do it in conjunction with finings or gelatin, it will also coagulate and pull protien out of your beer, reducing chill haze and clarifying it even further.

 

[124Spider]

Sounds interesting; I'll have to read up on that!

 

[ICWiener]

Defintiely look into it. Some people swear by it.

I've done it a few times and found that it doesn't affect my beers enough for me to put forth the effort. But, to each his own.

 

[rgarry]

I find that it really drops everything out of the beer and I always do it on very lite colored beers and tend not to do it on darker beers. I don't think it effects the taste but really improves the clarity. Non Home Brewers like a clean beer without anything floating in it. Homebrewers understand and don't care.

 

[124Spider]

Given that I now have the equipment to easily do the cold crash, is there any reason not to do it? This seems especially relevant to me now, since I do not plan to secondary ferment. It's a brown ale.

 

[rgarry]

If you bottle, it takes a bit longer to carb up since a bunch of the yeast settle out. I just revived an old thread on this very subject. I never bottle but have a Belgian that I won't drink for 6 more months and recs here were to age in bottles. I should have an issue since it will be carved in my time frame.

 

[ICWiener]

Given that I now have the equipment to easily do the cold crash, is there any reason not to do it?

It all depends. Let's say you have a stout in there, there is not a lot of incentive to do it. The clarity issue doesn't apply and you'd be taking up that space for an additional day or two. If you're brewing frequently, you're going to want that space for new beers. If you're not brewing that often, I say crash 'em. It's easy with a temp controlled fridge. The only reason I don't do it is because my fermenter is also my long term storage for aging sour beers. I don't want to pull out 4 or 5 full carboys every time I need to crash an IPA.

As for the brown ale you've got now...if you want to, go for it. But like rgarry said, it doesn't make a ton of difference on darker beers.

 

[paulegli]

I just bought a chest freezer off craigslist for $60.00 and bought the STC-1000 from ebay. With the STC-1000, project box, plug & cover I spent about $35.00.

Make Magazine has step-by-step instructions showing how to wire up the STC-1000 in a junction box:

http://blog.makezine.com/projects/water-bath-thermostat/

I've used this controller connected to a mini fridge and heating wrap for both fermentation temperature control and cold crashing. It really comes in handy when you're brewing a recipe which calls for changing the temperature during fermentation. If you ferment in carboys, this carboy cap is a great way to place your temperature sensor in the middle of your fermenter so you get a more accurate temperature reading.

Happy brewing!