Wort Temperature in Fermentation Chamber?

[roxy35]

Hey all,

I just set up my fermentation chamber with a Ranco 2-stage and am a "little" concerned with early temperature fluctuations. I've set cooling at 68/2 and heating at 66/2. My water (practice round) went in at about 52 degrees so I know my heat had to work awful hard to bring the temp up. I checked at one point - the water was up to 61 but the inside temp of the freezer was 114!

I checked an hour later, water was up to 65, freezer was 67. It looks like it all balanced out eventually.

My question is: Are my settings OK to avoid temp fluctuations? I understand it will take some time to stabilize initially but will balance out. The problem is that the time when it can fluctuate the most is when I need it to be the most constant. I should also note that I have the probe insulated to the side of my bucket. I've read a lot about whether to let it dangle or not, but I've opted to measure actual temperature vs. ambient.

 

[TomSD]

Where is your probe? I get best results putting it against the side of my carboy with sponge or something so it is reading the carboy and not the ambient. Once you get that your fluctuations will be slow and small not radical.

 

[roxy35]

Where is your probe? I get best results putting it against the side of my carboy with sponge or something so it is reading the carboy and not the ambient. Once you get that your fluctuations will be slow and small not radical.

I also have it insulated to the carboy. With my settings, I understand that it will COOL once the temp has risen to 70 until it's back to 68. It will HEAT when it drops to 64 and bring it back to 66. Should I close this gap, or does this seem ok? Maybe it's me, but a 6 degree change seems like a lot. Of course I know it won't swing 6 degrees at once since the freezer will do a lot to retain the heat/cold.

 

[TomSD]

I use a much smaller window on my setup. The only time it is any strain is when you first drop it in. I minimize that by getting close to my target with cooling before pitching.

 

[roxy35]

I use a much smaller window on my setup. The only time it is any strain is when you first drop it in. I minimize that by getting close to my target with cooling before pitching.

If you don't mind me asking, what are your settings?

I also plan on making sure it close to the target range before I put it in - maybe even leaving it in room temperature to stabilize (fermentation chamber is for the wife who is furious with the fermenting beer smell)

 

[Doomsday]

how long was the air temp at 114!? How high did your wort temp get?

 

[TomSD]

I think it is around 3 degree swing... I'd have to go out and check to be sure. The ambient taking big swings isn't too big a deal really as your only concern is the carboy temp. Again the only time I have noticed a big swing like that is initially. You might want to get info from others though as not everyone has the same experience.

 

[fifelee]

Doesn't sound like you had any fluctuations. Only your heater was on until the beer reached temp. The hot air left in the chamber doesn't have much thermal mass (compared to the beer) and I'm sure it quickly evened out to near your set temp.

If you want the temp to rise slower then put the probe in a small glass of water that will heat up quicker then the large volume of beer. It might take a day for your beer to near the sent temp, but your chamber wont get so hot. Then transfer the probe to the fermenter.

I sent mine to +/- 1 degree from set temp. Even at that your frig will cycle less then when being used as a frig. Then it is trying to keep food at 39 in a 70 degree house not keep beer at 68 in a 70 degree house.

 

[roxy35]

Alright cool, it sounds like things are going as expected. I checked this morning and temp was 61 inside the chamber, 64 off the Ranco. Not bad, but I think that may be a bit cold. I went ahead and changed my settings to 67/1 cool and 66/1 heat. Therefore it will fluctuate from 68-65. I may go up to 69-66 eventually. I love the precision I can get now!

Do you notice your chamber cycling alot with a a 3 degree swing?
Also, do you change your settings during active fermentation?

 

[broadbill]

how long was the air temp at 114!? How high did your wort temp get?

114 sounds worse that it actually is, when you consider the thermal mass of the air inside the chamber compared to the thermal mass of 5-6 gallons of liquid.

It probably does take that much energy to bump that much liquid from 52 to 68...

 

[TomSD]

I'm using a Love controller so I just change one thing. I don't change it unless I there is a reason though and typically not in the middle of a fermentation.

For example my wheat went in on the 7th... its range is 59-75 so I set the temp to 61. On the 14th I added my Trappist with a range of 64 to 78. At that point the wheat was done with its most active fermentation anyway but either way the new setting of 66 was well within its range. I realized this week that i pitched the wrong yeast for the Trappist so it should be in the 66-74 range. At that point I pushed it up to 68.

Like I said though I won't play with the temps unless I add a new carboy with a different range (the probe moves then too) or if fermentation stalls and I want to roust the yeasties back into production.

 

[roxy35]

I'm using a Love controller so I just change one thing. I don't change it unless I there is a reason though and typically not in the middle of a fermentation.

For example my wheat went in on the 7th... its range is 59-75 so I set the temp to 61. On the 14th I added my Trappist with a range of 64 to 78. At that point the wheat was done with its most active fermentation anyway but either way the new setting of 66 was well within its range. I realized this week that i pitched the wrong yeast for the Trappist so it should be in the 66-74 range. At that point I pushed it up to 68.

Like I said though I won't play with the temps unless I add a new carboy with a different range (the probe moves then too) or if fermentation stalls and I want to roust the yeasties back into production.

I thought I read somewhere that active fermentation can raise the internal temp 7-8 degrees over what the outside of the fermentation bucket shows. If the outside is reading 68, but during the most active time it is actually 75-77, I would be a little concerned. Have you had any experience with this? Maybe I'm just over thinking/worrying a little too much.

 

[broadbill]

I thought I read somewhere that active fermentation can raise the internal temp 7-8 degrees over what the outside of the fermentation bucket shows. If the outside is reading 68, but during the most active time it is actually 75-77, I would be a little concerned. Have you had any experience with this? Maybe I'm just over thinking/worrying a little too much.

correction: active fermentation will raise the internal temperature 7-8 degrees over ambient temperature, not what the outside of the bucket shows (I assume you are talking about a stick-on thermometer).

Actually, the fermentation vessel will be close to what the internal temperature reads (which is why it is recommended that you tape the controller to the side of the vessel).

 

[TomSD]

What broadbill said... you are mostly negating that problem by attaching the probe to the carboy (or whatever). I also generally set my temps to the low end of the suggested range for the particular yeast.

 

[roxy35]

Great! Thanks for your help!

On a side note, I just finished up my American Pale Ale and placed it in the chamber. The water that I had in there read 67 on the Ranco and I tested the actual water with a separate thermometer and guess what - 66.7 (WOW!).

I have my settings 68/1 cooling and 67/1 heating. It should fluctuate from 69-66 degrees. I am little worried this is overkill, but since it measuring actual wort it shouldn't move TOO much (not sure, first time with wort in chamber).

We'll see!

 

[roxy35]

Just a quick update on my progress:

I have modified my settings a little bit out of concern for my compressor. The freezer is 10 years old and scored it off CL for $40. Even though cheap, I'd still like to extend its life. I moved it to 68/2 cooling and 67/1 heat. I figure now the freezer will have to raise up to 70 before the compressor will kick on. I am using California Yeast and the ferment temp is 66-70, so I think I should be in the ideal stomping ground.

This morning I checked and my digital freezer thermometer read 64, the ranco which is insulated against the bucket (using a foam Magic Eraser - genious!) was at 67 and my stick on thermometer on the bucket lit up 68 in green and then 70 in blue, so I'm assuming somewhere in the 69 range. This would mean the Ranco is off 2 degrees or the stick on is off 2 degrees (I'm going with the later just to the superior technology.) Each time I have looked at my Ranco it has registered at 67 which I believe is ideal! Now, as long as that truly is the wort temperature, the waiting game should leave me with some good, good beer!