Temp Control Rant

[bigdongsr94]

So I am not sure the point of this post but i am on the fence about getting better ferm temp control. Why would i be on the fence, its the best improvement to home brew says JZ and others...Well i am not sure if i am alone here but i call ********. Its not like i ferment my ales (all i brew) in the garage or outside under the sun. My brew room in the basement stays at 65 F. Its maybe 3 degrees warmer then i would like but when reading about temp control many people set about that temp. So whats the deal? I have a lot of pieces parts and can build a controller for my keg fridge so i can try it a few times. I keg vary seldom. Before i take that step i just want to say i dont believe it will do anything.

I guess if there is one question to ask, can anyone give me personal experience or materials that would suggest temp control of the wort provides improvement? What i mean is not controlling the environment but placing an RTD or TC in the fermentor and controlling the temp of the frig that way rather than the outside temp. This would try to stop temp increase during the main portion of fermentation. If i do build a controller for my fridge i would prob control the temp via the wort temp but im just not sure. Some people say the temp increase during ferm is good. Anyone with details from the book Yeast? I do have a logger on my fermentation cabinet to really document the outside temperature. I will pull the data later tonight or tomorrow to see that I dont get temp swings.

 

[pennyloaf]

I don't have a basement and it is hot where I live (Texas). I use the controller to set and forget my beers in the fridge. I put the thermometer on the side of the carboy so while your room may be constant temperature - the beer may vary. My understanding is that you want to start the temps as low as possible to reduce off flavors and ramp up the temp as the fermentation is finishing to finish off any reactions that take more activation energy.

I don't know if doing a whole setup is worth it for you but I will say I built my temperature controller for ($22 STC-1000, $10 radio shack project box, $2 outlet, $10 heavy gauge extension cord = $45)

If you want to lager, cold crash, or ferment different temperatures temperature control is nice. This would also let you add a heater if you want to heat in the winter.

If I had good temperature control like you do in the basement and are content with ales and the beer you are currently making- I probably wouldnt get a big controller either.

 

[bigdongsr94]

Stc1000 eh. Let me check that out. I have overtemp switches and some other industrial controls but I'm all for more amazon goodies.


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[bigdongsr94]

Looks like the rant was worth it. If I go to a controller it will be a stc-1000. My thermastats I have aren't as nice.


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[bigdongsr94]

Do you know the diameter if the temp probe for the stc-1000? I wonder if it would fit in a push lock fitting? Is it a sealed end so I can put it thru the ferm wall?


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[opiate82]

Well, I don't know what else to tell you other than temp control during fermentation most definitely is NOT BS and it is, in my opinion, the next most important thing after sanitation that a homebrewer can do to improve the quality of their beer.

Fermentation generates its own heat. If the ambient air in your basement is 65*F the temperature inside your fermenter is higher than that. I have seen differences as high as 10*F.

Unless you are making beers where ester-flavors are desirable (e.g. saisons), I know your beer would greatly benefit from better temperature control.

 

[kh54s10]

In my case my basement is half finished. I use it as my man cave and keep it a bit too warm for fermenting. In the winter I need to cool because of the heater, in the summer it is too hot. So I temperature control (cooling) year round.

I did one too warm when I started, all the ones since were controlled and better.

I went for convenience with my controller and bought a Johnson A419. No need for any wiring.

 

[hunter_le five]

Well i am not sure if i am alone here but i call ********.

You're welcome to disagree, but all I know is my beers improved drastically after I started using temperature control. I think the vast majority of experienced brewers are going to agree with me.

Its not like i ferment my ales (all i brew) in the garage or outside under the sun. My brew room in the basement stays at 65 F. Its maybe 3 degrees warmer then i would like but when reading about temp control many people set about that temp. So whats the deal?

65*F ambient temp does not equal 65*F wort temp. Wort temps can rise well above ambient during active fermentation due to heat generated by the yeast, hence the need for temperature control.

But I will grant you that having a 65*F ambient temp space to ferment in is better than many of us have. I live in Texas, no basement, so my ambient temps are 72*F-80*F, depending on where I am in the house. Temp control is critical for me.

I have a lot of pieces parts and can build a controller for my keg fridge so i can try it a few times. I keg vary seldom. Before i take that step i just want to say i dont believe it will do anything.

And I believe that you will find that it WILL do something. But you won't know until you try, will you?

I guess if there is one question to ask, can anyone give me personal experience or materials that would suggest temp control of the wort provides improvement?

Anecodotal, but my beer is MUCH better.

What i mean is not controlling the environment but placing an RTD or TC in the fermentor and controlling the temp of the frig that way rather than the outside temp. This would try to stop temp increase during the main portion of fermentation. If i do build a controller for my fridge i would prob control the temp via the wort temp but im just not sure.

Controlling the wort temp is certainly FAR more important that controlling the "fridge tem" or ambient temp. That's why I installed a thermowell in my fermenter, so the probe is measuring beer temp at all times and adjusting accordingly, instead of the air around it.

Some people say the temp increase during ferm is good.

I like to increase the temperature a bit as fermentation is winding down, in order to maximize attenuation and aid in yeast clean-up, but during active fermentation, I keep temps on the lower end if the spectrum to minimize esters.

There are benefits to temp control beyond just primary fermentation. There's also D-rests, lagering, cold crashing, etc. Do you NEED a temp controlled-fridge to do this? No, but it makes it a hell of a lot easier.

 

[QuercusMax]

Temp control doesn't *have* to be with a fridge and digital thermostat thingy. It can be as simple as putting your bucket/carboy in a water bath, maybe with some frozen water bottles to keep it cooler.

I ferment most of my ales in my basement which stays in the low 60s, with no extra equipment. I've won some medals with them, too. But I've also had some crappy batches when my basement got really warm in July.

 

[balrog]

And don't forget to check out AlphaOmega's insanely fun firmware upgrade for the STC1000, giving profile ramping, hysteresis and delay adjustment and °F display. Or if you really want to geek out, there's now a Do It With A Spare PC True PID controller by FuzzeWuzze, here.

 

[bigdongsr94]

Well, I don't know what else to tell you other than temp control during fermentation most definitely is NOT BS and it is, in my opinion, the next most important thing after sanitation that a homebrewer can do to improve the quality of their beer.

Fermentation generates its own heat. If the ambient air in your basement is 65*F the temperature inside your fermenter is higher than that. I have seen differences as high as 10*F.

Unless you are making beers where ester-flavors are desirable (e.g. saisons), I know your beer would greatly benefit from better temperature control.

Well lets look at what you said...You have seen differences of 10*F but aside from a response below nto many people control to the temp of the wort but rather just the frig temp and you can bet those are different through a plastic bucket. Also i would like to document my own findings but i believe that i had read a math equation that shown that a rather big OG 5G brew could only increase around 7*F under fermentation... Like i said I am really wanting to do this but i jsut really doubt my beer is going to be better by an order of magnitude like what is expressed all over now days. Keep in mind...I have it at a nice temp.

 

[bigdongsr94]

Controlling the wort temp is certainly FAR more important that controlling the "fridge tem" or ambient temp. That's why I installed a thermowell in my fermenter, so the probe is measuring beer temp at all times and adjusting accordingly, instead of the air around it.

+1 on the Thermowell. Thats what i am wondering about. Does your Frig cycle a lot or do you see big swings since there must be a lag between SP and PV. Im a controls guy: Set Point and Process Variable.

 

[hunter_le five]

....but aside from a response below nto many people control to the temp of the wort but rather just the frig temp and you can bet those are different through a plastic bucket.

I think that maybe you don't realize how many people DO control/track wort temperature as opposed to ambient temp. I know I'm not the only one on here doing it, and I certainly didn't invent the practice. When we talk about temp control on this board, we are talking about the wort temp, not ambient.

I will grant you, if all you're doing is controlling ambient temps around a plastic bucket, it may work as well, as plastic is fairly insulative. You either need to use a thermowell, or tape/insulate the probe to the fermenter, or manually check the wort temps and adjust ambient temps accordingly.

Also i would like to document my own findings but i believe that i had read a math equation that shown that a rather big OG 5G brew could only increase around 7*F under fermentation... Like i said I am really wanting to do this but i jsut really doubt my beer is going to be better by an order of magnitude like what is expressed all over now days. Keep in mind...I have it at a nice temp.

7 degrees is a HUGE difference, don't discount that.

I can assure you, if you control your wort temps properly, it WILL make a difference. If you find that it doesn't, I'll buy you a beer. :cross:

 

[hunter_le five]

+1 on the Thermowell. Thats what i am wondering about. Does your Frig cycle a lot or do you see big swings since there must be a lag between SP and PV. Im a controls guy: Set Point and Process Variable.

The fridge cycles infrequently and swings are ~2*F. That's with the controller set to a 1*F differential. It takes a while for that much thermal mass to change when it's inside an insulated box (in my case, a chest freezer).

Right now I have it set to 64*F. As soon as the temp reaches 64*F, the compressor cycles until it drops to 63*F, but it will generally continue dropping to 62*F. It will then take quite a while to raise back up to 64*F.

The swings in ambient temp are HUGE, but wort temp swings are fairly minimal with my setup.

 

[bigdongsr94]

Well rant worth it. I like the info. I do still believe that most control via a frig temp or whatever and not their wort. That's what i read. And plastic is a decent insulated...that's also my point.


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[balrog]

I approached temp control as a question of automating temp profiles and also gaining consistency brew to brew. My basement (Massachusetts) during Spring/Fall, stays really stable--or so I thought--until I got a $20 temp logger off Ebay and found "stable" was 57°F-68°F. If I want the same estery profile of English style yeasts to repeat, I need to ferment them at similar temperatures. Some yeasts have temp/ester profiles that are very tight. I've even read a "clean" yeast S-05 is "peachy" at 62, "clean" at 66, and "fruity" at 69. So I really want to hold my wort temp fermenting within a degree or 2

And for temp profile, as mentioned before, after the primary fermentation has completed in 4-7 days, I want to slowly ramp up then temp to help the yeast finish and clean up before dropping temp to help drop them out.

 

[Pilgarlic]

Well rant worth it. I like the info. I do still believe that most control via a frig temp or whatever and not their wort. That's what i read. And plastic is a decent insulated...that's also my point.

You're right. That's why I, and I'd guess most, who place the sensor on the side of the fermentor make sure that we cover that sensor with a better insulator than the wall of the fermentor. In my case, it's multiple layers of dry terrycloth covered in duct tape. I sometimes also use bubble wrap. I'm quite confident that I'm getting my reading from within the fermentor rather than from without because my chest freezer is often held at near freezing temps for an extended period in an effort to fight that wort temp down to the low 60's.

Some also ask about a temp gradient within the fermentor, and whether a thermowell isn't necessary for that reason. I'm not concerned about that because during active fermentation, while the ferment is exothermic, there's a good bit of churning going on in the fermentor which would mitigate against much appreciable thermal stratification.

This is a very common, low-tech and, I believe, well-conceived and effective approach for most beers.

That said, if I were doing a 13% RIS, I might be more comfortable with a thermowell!

 

[TimmyWit]

I have to disagree that people are measuring ambient temp in their ferm chambers. Why would one make the investment in a ferm chamber but not try to get the most out of it? Do you remember where you read that?

As far as relying on ambient temp for fermentation, I think it depends on what kind of yeast you're using and what type of beers you're brewing. If you're using 1056 and brewing IPA's, you might have good results fermenting at 65F ambient. You're mostly looking for a clean ferment from your yeast and the hops will help mask off flavors if your temps run a little wild. But, if you're interested in seeing what type of phenols or esters you can milk out of a yeast at varied temps, you will need to control your temps. If you have a finicky yeast that will not attenuate if it isn't treated appropriately temp wise (3724), temp control is a must. If you want a hefe that's not a banana bomb, temp control will help with that too. I think it really depends what you're going for. If you're happy with your beer, that's all that really matters.

 

[opiate82]

Well rant worth it. I like the info. I do still believe that most control via a frig temp or whatever and not their wort. That's what i read. And plastic is a decent insulated...that's also my point.


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The majority of people with temp controllers will tape the probe onto their fermenter with some sort of insulator surrounding and protecting the probe from the ambient air. For a 5 gallon batch the temperature reading from a probe on the side of a fermenter and the temperature measured from the middle of the wort will be within 1 degree of each other. For larger batches a thermowell is probably in order.

The people who control just their fridge temp will usually at the very least have one of those sticker thermometers on their fermenter and adjust their fridge temp based on what that thermometer is reading, not based on the ambient air of their fridge. Not quite as accurate, but still better than just relying on the ambient air alone.

I'm not sure where you are getting the idea that "most people" don't monitor the temperature of their wort but the majority of what I have read on the subject on these forums states just the opposite.

 

[bigdongsr94]

Ok enough already..just joking. I am going to Obama my "most people" statement and act like I didn't say that. What I meant was most don't have thermowells. To be honest I don't really think measuring the side is measuring the wort but if it gets good results and the temperatures are within your personal delta then good. But saying that measuring the side insulated is measuring the ambient temp of the ferm chamber is incorrect on my part.


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[BigFloyd]

Considering what most of us spend on assorted brew gear, plopping down $25-30 to build an STC-1000 outlet box and another $50-75 for a used fridge to gain precise temp control is a no-brainer to me.

On the question of probe placement, there have been some folks on HBT who ran side-by-side readings using one probe taped to the side of the bucket/insulated and a second probe inside a thermowell in the middle of the liquid. The biggest recorded difference (when there was one) was an insignificant +1 degree F at the thermowell probe. I get very stable readings with the probe taped and insulated, so I find that to be quite satisfactory.

 

[LandoLincoln]

Well lets look at what you said...You have seen differences of 10*F but aside from a response below nto many people control to the temp of the wort but rather just the frig temp and you can bet those are different through a plastic bucket. Also i would like to document my own findings but i believe that i had read a math equation that shown that a rather big OG 5G brew could only increase around 7*F under fermentation... Like i said I am really wanting to do this but i jsut really doubt my beer is going to be better by an order of magnitude like what is expressed all over now days. Keep in mind...I have it at a nice temp.

My friend and I started fermenting in his basement. His basement is a nice stable 62°. We started out with carboys without thermometer stickers on them and we were making decent beers, but we'd get off-flavors. So we bought some thermometer stickers and he found out that our beers were getting into the 70's. So we switched to a chest freezer and a temp controller, and then we taped the probe to the carboys. Beer stayed at a nice 65° or so. No more off-flavors.

You may doubt that your beer is going to get better, but I don't.

 

[bigdongsr94]

Stc 1000 is now on its way. All future questions on hbt willbe jn the form of rants that contradict what most believe.


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[BigFloyd]

Stc 1000 is now on its way. All future questions on hbt willbe jn the form of rants that contradict what most believe.


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Lol.

 

[Smellyglove]

Well. Theres a difference between having a stable temperature, and having control of the temperature.

Being able to raise/lower temperature is absolutely not cruical, but it helps. Lets say you're making a beer and need to raise the temperature after initial fermentation, or just want a higher/lower temperature than your ambient temperature the room/garage/basement, how would you do that without turning on/off heaters/ACs? If you have a fridge it's easy to set a STC to 2C and cold crash in the same place as you've fermented it.

I use fridges with heating belts and STCs wired into them. Since this is a hobby I spend a good deal of time on the fridges were great investments (cheap/free) since I can now focus on other things in my brewery and I know I can trust the fermentation is going according to my plan. Gives more consistency and it's one factor less to think about if you're trying to replicate a beer or do some changes to it.

 

[FiddlersGreen87]

Fermentation generates its own heat. If the ambient air in your basement is 65*F the temperature inside your fermenter is higher than that. I have seen differences as high as 10*F.

Single best argument for temp control.

The temp difference between just a liquid and the rest of the room is going to be different because they will always be exchanging heat to attempt to reach balance.

In the case of your brews there's an active reaction going on inside which generates energy as a by product because nothing is 100% efficient. Energy comes out in the form of heat, and several other forms that don't have any impact here.

I don't believe temp control will make a bad beer better, but like others have mentioned, if you want to fine tune your process and have a better result, controlling this stage will improve the process of what's happening during the fermentation.

 

[Smellyglove]

To put it this way. You can nail all the temperatures and volumes and what not during the brewing process, if you botch the fermentation all that work is wasted.

You can make mistakes in the brewing process, but nailing the fermentation will still make good beer, even if it wasn't intended to end up that way because of mishaps in the brewing process.

 

[Sir-Brews-Alot]

Let’s not forget that you also want to prevent temperature swings. I know my basement, at least, the temperature will fluctuate a good 5-10° between daytime and nighttime temperatures. Doesn’t seem like much, but yeast will behave better at a stable temps. Fact is you will produce better beer that has fermented at exactly 65° for 24 hours than beer that has gone from 65° to 70° back down to 65° over a similar time period.

Also I do not use a thermowell, I tape the probe to the side of the carboy and tape an insulating layer over the probe. When I first started temp controlling my fermentations, I measured the temp of my wort while actively fermenting over several batches with my Thermapen and it measured exactly the temp displayed by my Temp Controller. IMO a thermowell is not needed to accurately measure wort temps.