Yes, Virginia, fermentation temp control really IS important.

[smizak]

Not sure what you mean by one minute hysteresis. Is that the compressor run time?

I mean that the temperature has to be solid over or under the set temperature for one minute before either stage kicks on. Stops it from cycling too much. You could call it duty cycle too. The one minute seems to keep it dead-on, a good compromise between outside air influence and real fermenting wort temperature.

 

[Crito]

I leave my wort to chill overnight too. I put the controller about three degrees higher then my target. Usually its in target when everything averages inside the chest freezer.

Decent Water filter and temp. Control are the major factors from my old decent rating to world class beer rating.

 

[Darwin18]

This is a good topic that many homebrewers that I've met fail to appreciate, and its something that I see everyday on these forums. There are tons of threads on here of people agonizing over mash pH, ounces of specialty grains, putting together a delicate yet sophisticated hop schedule, but who choose to ferment at the ambient temperatures in their homes. There are likely a very small minority of people here who have a space in their home that maintains a constant ambient temperature suitable for each specific strain of yeast throughout the year, but most of our homes experience wide temperature swings throughout the day and night. Temperature control during fermentation is easily the most important factor of what goes into making a great beer, followed by yeast starters for liquid yeast, and aeration. Agonizing over the details while ignoring the major components of brewing great beer is something that I see a lot of here and in person.

I sincerely wish someone had emphasized the importance of temperature control to me when I first started brewing. Like many, I started out with a kit during Christmas and produced a drinkable beer. When I tried to brew in the summer I made beer that was atrocious and had to be dumped. It was incredibly discouraging and almost convinced me to leave the hobby before I gave temperature control a serious attempt. A water bath/swamp cooler can work but a chest freezer with a temperature controller on it is the way to go IMO. Nothing will impact the quality and consistency of your beer like temperature control. There is a thread on here with a guy who is making a 3 BBL brewery out of his house. He has shiny equipment. He does not have temperature control - without trying his beer, I would say politely that he's likely not making the best beer he's capable of.

Some people will be stubborn and insist that their ambient temperatures are sufficient. That's fine. I'll keep hanging ribbons up on my wall and have my friends brag about my beer to strangers (to my embarrassment) with my temperature controlled beer.

 

[malaeum]

Instead of dropping coin on an IC, why not just put the 74 degree wort into your keezer, let it come down to mid-60's, and *then* pitch yeast. It should only take a few hours to chill down to that level, and you're not really missing anything by waiting only a few hours. In cases where I haven't bought ice for my CFC and the beer has gone into the fermenter too hot, I've left in the fermentation chamber as long as overnight before pitching yeast, with no ill effects. A lot cheaper than buying an IC when you already have a plate chiller!

I suppose I was worried about some sort of infection. I figured if I get the yeast in there in short order it dominates any nasties picked up from the air but if I gave them time in that sweet environment they might take off before I pitch. I believe I value sanitation highly and with your advice it sounds like I am just being a bit overly cautious. Glad to hear that this would work as I really didn't want to spring for an IC after I just invested in a plate chiller (HOLY HELL do those things work SO much better than ICs).

I've brewed about a dozen batches with my old roommate and we always fermented in ambient temperatures. I'm ready to step it up to produce much better beers now that I am able to have my own equipment. Thanks very much for the advice!

 

[Larzean]

Probably a stupid question but recently got an old fridge to ferment in... I want to get a Johnson temp controller, what's the best way to handle the probe? Is there a way to get it directly into the wort? I use plastic buckets & better bottles

 

[BigFloyd]

Probably a stupid question but recently got an old fridge to ferment in... I want to get a Johnson temp controller, what's the best way to handle the probe? Is there a way to get it directly into the wort? I use plastic buckets & better bottles

Save your money. Get an STC-1000. I use three and they're excellent. Since you're in NY, you may also want the ability to run a small heater inside the fridge. The STC-1000 is a dual controller and will handle that just fine.

Simply tape the sensor to the outside of the bucket/BB. Tape a few layers of some kind of insulation (I use bubble wrap) over top of it. It will read the bucket temp which is only about 1*F cooler than the liquid sitting in the very middle of the bucket at the most active phase of fermentation (based on posts of folks who measured temps in both places at the same time).

 

[betarhoalphadelta]

Probably a stupid question but recently got an old fridge to ferment in... I want to get a Johnson temp controller, what's the best way to handle the probe? Is there a way to get it directly into the wort? I use plastic buckets & better bottles

"Best" method? In my opinion, it's a thermowell.

But before I had a setup that allowed for that, I would duct tape it to the side of the fermenter with a bunch of paper towels to insulate it from the fridge temps so I know it would be registering beer temp. Worked fine.

 

[Wynne-R]

Bwarbiany, really?

You wondered aloud about the possible need for tighter regulation.

I suggested a possible solution and explained how it might work.

Smizak apparently uses a similar method and gets ± .5°F.

Then you endorse the thermowell method, the largest possible temperature swing for a given controller.

https://www.homebrewtalk.com/f14/ye...ally-important-417013/index2.html#post5283920

 

[betarhoalphadelta]

Bwarbiany, really?

You wondered aloud about the possible need for tighter regulation.

I suggested a possible solution and explained how it might work.

Smizak apparently uses a similar method and gets ± .5°F.

Then you endorse the thermowell method, the largest possible temperature swing for a given controller.

https://www.homebrewtalk.com/f14/ye...ally-important-417013/index2.html#post5283920

I maintain that a thermowell is the most accurate way of measuring the wort temperature.

I would also think that the method you're referring to is more applicable to your fermentation in a water bath than for those of us fermenting in air in a fridge.

The specific heat of water [or wort] is SIGNIFICANTLY higher than the specific heat of air, so IMHO the overshoot of allowing the air around a fermenter to get quite a lot cooler than the wort would be significantly less impactful than allowing the water bath to get even a degree or two cooler than the wort. I just don't think the wort temp overshoot will be all that big of an issue from air temp overshoot.

I think my main issue if I wanted to reduce swings is that my current temp controller (Johnson) has a 1 degree resolution. Reducing that to 0.3 resolution with an STC-1000 (or similar) would be enough for me to be happy, and I think I could do that just as well with a thermowell (and not overtax my compressor) as I would get with your creative use of overshoot.

 

[Larzean]

Thanks for the input guys

 

[JohnSand]

I certainly am not saying that temperature is not important. But the test that started this thread had a fermentation temperature difference of 14f. The beer that rated poorly was fermented outside the published limits of the yeast. Brewers here are justifiably proud of the ability to control temps within one degree. Has anyone done a test with closer parameters? Say, 68 vs 70? Or 72? Numbers within the limits of the yeast? I would be interested to know.

 

[mtnagel]

https://www.homebrewtalk.com/f163/another-us-05-experiment-temperature-fluctuations-403882/

 

[LowNotes]

Not sure if this is what you are saying, but if you think that the fermentation chamber would have helped at all without more ice, see above.

Well, not exactly. My thinking was more along the lines of "even though I forgot to make ice, if I had the ferm chamber setup correctly, I could have cooled using my IC to mid 70's, poured my wort into my bucket, and then stuck it in the ferm chamber for a couple hours/overnight and simply pitched at a later time when the wort had been brought down to 64*.

It isn't the *best* solution, but I think it would have worked. And it certainly would have addressed the issues on the after-pitching side of things.

The silver lining here, is that this is my 4th time brewing this particular beer with only minor tweeks each time. So I should be able to use this as an opportunity to refine my palette and compare the differences form this batch to the last few. I even have 12 bottles left from my 3rd time brewing this beer, so I could do a side-by-side. I may be weird, but I actually get a fair amount of enjoyment when I make mistakes with this hobby, because every one so far has helped to further my knowledge of brewing, and especially with regards to refining my own process.

 

[isleofman]

I use an STC-1000 and a chest freezer. I started off using the probe "taped to the side of the fermenter with insulation" and had wild temperature swings. So much so, that the fermwrap would usually kick on after the cool cycle, only to cause the cool cycle to kick back on after that, etc. I tried all kinds of configurations and setting the temp ± higher. Nothing really helped. I bought one of these http://www.brewershardware.com/24-Stainless-Steel-Thermowell-TWS24.html and now the giant swings in temp have disappeared. I highly suggest the thermowell over "tape to the side."

 

[Wynne-R]

I maintain that a thermowell is the most accurate way of measuring the wort temperature.

I agree. That doesn’t mean it’s the most accurate way of maintaining a temperature.

The specific heat of water [or wort] is SIGNIFICANTLY higher than the specific heat of air, so IMHO the overshoot of allowing the air around a fermenter to get quite a lot cooler than the wort would be significantly less impactful than allowing the water bath to get even a degree or two cooler than the wort. I just don't think the wort temp overshoot will be all that big of an issue from air temp overshoot.

You miss my point. Since the air temperature changes so much faster than the beer temp, this is the overshoot I’m counting on. Instead of chugging away at the delta T beer temp all at once, we can take little bites at it. Smaller cycles, better regulation.

 

[Gameface]

I use an STC-1000 and a chest freezer. I started off using the probe "taped to the side of the fermenter with insulation" and had wild temperature swings. So much so, that the fermwrap would usually kick on after the cool cycle, only to cause the cool cycle to kick back on after that, etc. I tried all kinds of configurations and setting the temp ± higher. Nothing really helped. I bought one of these http://www.brewershardware.com/24-Stainless-Steel-Thermowell-TWS24.html and now the giant swings in temp have disappeared. I highly suggest the thermowell over "tape to the side."

I use the tape to the side method but I had some extra foam insulation left from my keezer build so I made a 5"x5" block of 1" thick foam insulation and I cut a very small recess for the probe right in the center, and then put a 1.5" square piece of aluminum foil over the recess before pressing the probe into place and putting a thin strip of tape over it to hold it in place. Then I take a ridiculous amount of duct tape (in my case gorilla tape) and strap it to the side of my speidel tank so that it is compressed against it somewhat and there is no path for air to enter at all.

I experience no temp swings. As far as I can tell the temp I'm reading is pretty close to the temp of the wort. My fermentor also barely fits, I actually have to squeeze it into the freezer and it's contacting all four walls.

I wouldn't mind a thermowell, though. That is the very best option, imo.

 

[Setesh]

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