17 replies to this topic

[ColdAssHonky]

I have an IPA that I brewed on Sunday sitting in a water bath in my basement. I pitched on a slurry of S05 and would like to keep the ferm temps at 65. I'm rotating frozen water bottles through the bath, but I can only check the temps and replace the bottles early in the morning and again at night. Is there anything to worry about with small fluctuations in temp, up and down, say within 5 degrees?

[gnef]

five degrees is quite a bit, and you may notice some off flavors. Honestly though, if that is the best you can do, then don't fret about it. If you can get a freezer with a temperature controller in the future, that would be ideal, but for now do the best with what you have!

[JReigle]

I think you should be OK, obviously proper temp control is superior. In my experience with this setup using partially submerged buckets, say the submerged fermenter is in the 62F range in the morning, water @ 63F or so, by evening the water is ~ 67-68F but the fermenter is still about 64F. The surrounding water provides the thermal buffer and the fermenting beer stays a more consistent temperature, which only sees a ~1-2F rise and fall during the 24 hour cycle despite the surrounding water rising and falling ~5-6F.

[3rd party JKor]

Disclaimer: The following idea is quite wacky...Fermentation temperature control, without a temperature controller:Make up several blocks of ice (in a 16oz plastic drinking cup, for example), then take an equal number of lengths of string and 3/8" hex nuts. Tie the hex nuts to the end of the string and sink the nuts into the drinking cups at several different depths. After the cups of water are frozen, hang them above your water bath. As the ice melts the blocks will drop into the fermenter, the deeper the nut was dropped into the cup, the longer it will take to drop in. With some experimentation, I bet you can get a very stable system over the course of 12, or maybe even 24, hours..

[ThroatwobblerMangrove]

It's pretty rare that I have to submerge my fermenter. I can usually keep the total temperature range to about 3 degrees and I don't think I'm contributing any off flavors. I basically just make sure I chill the wort down plenty and then leave the fermenter in a reasonably cool place and I'm good to go. Back in the day there were no glycol jackets or anything and I bet they managed to make some good stuff.JK - that's a pretty neat idea.

[chadm75]

I could only get my wort down to 80 degrees yesterday, ground water temp is still too warm...ugh! Fermenting my MLPA at 72 right now....yikes!

[ColdAssHonky]

I think you should be OK, obviously proper temp control is superior. In my experience with this setup using partially submerged buckets, say the submerged fermenter is in the 62F range in the morning, water @ 63F or so, by evening the water is ~ 67-68F but the fermenter is still about 64F. The surrounding water provides the thermal buffer and the fermenting beer stays a more consistent temperature, which only sees a ~1-2F rise and fall during the 24 hour cycle despite the surrounding water rising and falling ~5-6F.

I don't have a way of monitoring what's going on in the bucket, so I have to go off of the water temp. If I'm understanding you correctly, I shouldn't assume the fermentation temperature has risen 5F just because the water bath has.

Disclaimer: The following idea is quite wacky...Fermentation temperature control, without a temperature controller:Make up several blocks of ice (in a 16oz plastic drinking cup, for example), then take an equal number of lengths of string and 3/8" hex nuts. Tie the hex nuts to the end of the string and sink the nuts into the drinking cups at several different depths. After the cups of water are frozen, hang them above your water bath. As the ice melts the blocks will drop into the fermenter, the deeper the nut was dropped into the cup, the longer it will take to drop in. With some experimentation, I bet you can get a very stable system over the course of 12, or maybe even 24, hours..

That's one too many frozen nuts than I'm looking at keeping track of right now. I'm counting down the days until I can get a freezer w temp controller.

[ThroatwobblerMangrove]

I don't have a way of monitoring what's going on in the bucket, so I have to go off of the water temp. If I'm understanding you correctly, I shouldn't assume the fermentation temperature has risen 5F just because the water bath has.

That's possible - what do you think the air temp is?

[ColdAssHonky]

That's possible - what do you think the air temp is?

Let's see here... yesterday's average high/low was 71/50, but we did just have a streak of hot weather, so basement temp could be around 70F I suppose. Need to get something set up down there to keep track of that I suppose.

[ThroatwobblerMangrove]

Let's see here... yesterday's average high/low was 71/50, but we did just have a streak of hot weather, so basement temp could be around 70F I suppose. Need to get something set up down there to keep track of that I suppose.

I mean - if the air temp is contributing to the water temperature going up that hopefully means the fermenter temps didn't actually swing that much.

[brewguy]

five degrees is quite a bit, and you may notice some off flavors. Honestly though, if that is the best you can do, then don't fret about it. If you can get a freezer with a temperature controller in the future, that would be ideal, but for now do the best with what you have!

Is five degrees really significant? I have a Johnson Controller, and it has a 3 1/2 degree differential. I would think that a 3 to 4 degree temp variance is the best that anyone can do. Even the more expensive controllers must have a few degrees of temp swing.

[3rd party JKor]

Is five degrees really significant? I have a Johnson Controller, and it has a 3 1/2 degree differential. I would think that a 3 to 4 degree temp variance is the best that anyone can do. Even the more expensive controllers must have a few degrees of temp swing.

You can keep it pegged in within a degree if your controller is properly tuned.

[gnef]

Yes, I have my digital love temperature controllers set for a 1 degree Fahrenheit limit, with a 15 minute off time between cycles to prevent the compressor from being cycled too quickly.

[brewguy]

You can keep it pegged in within a degree if your controller is properly tuned.

The 3 1/2 degrees swing is built into the specs of the controller, so I cannot tune it. Here is the controller I have, Johnson Controls. This is what the NB site says about 3 1/2 deg of temp swing:

The Johnson Control thermostat has a 3 1/2 degree differential, which means that the thermostat will shut the fridge or freezer off (stop cooling) at 3 1/2 deg below the setpoint and start the unit (resume cooling) once internal air temperature exceeds the setpoint—the effect of this fluctuation on the actual temperature of fermeting wort or beer will be insignificant.

[3rd party JKor]

The 3 1/2 degrees swing is built into the specs of the controller, so I cannot tune it. Here is the controller I have, Johnson Controls. This is what the NB site says about 3 1/2 deg of temp swing:

By 'you' I didn't mean YOU. I meant people who have a controller that they can set the deadband on, or use PID tuning.

[Stout_fan]

By 'you' I didn't mean YOU. ...

Well, that kind of depends on what the definition of 'is' is.

[3rd party JKor]

Well, that kind of depends on what the definition of 'is' is.

Who let you in here?

[BrianBrewerKS]

I could only get my wort down to 80 degrees yesterday, ground water temp is still too warm...ugh! Fermenting my MLPA at 72 right now....yikes!

I wouldn't worry about it too much. I brewed a MLPA this past weekend too. I didn't have my kegerator warmed up enough to ferment the batch in there (kegerator was at ~ 35 degrees) so I just put it on the floor downstairs. During the peak of fermentation, it got up to 74-75 degrees...now it's back down to 70-71. I'm sure it might end up with a lil more esters than if it'd been fermented cooler, but I think that'll be okay with an MLPA...even interesting.