2 carboys in ferm chamber

[sorefingers23]

just upgraded my brew rig and started doing 10g batches, so no I have 2 car boys in my ferm chamber at the same time. How should I go about temp control, tape the Probe to one carboy and assume they will both stay around the same temps, or set the ferm chamber to temp and let it go like that.

 

[day_trippr]

fwiw, I do the former. Using chamber temperature alone for control is far less capable of maintaining accurate wort temperature during active fermentation, ime...

Cheers!

 

[Harleybrew32]

I would go with the taped to one carboy on the outside and see how the other one does.
I use Tilt Hydrometers so i can monitor 2 different brews, but i have two chambers.

 

[DVCNick]

Even if they started off at significantly different temps, they would equalize pretty quickly... I'd go with the first option with no concerns at all.

 

[sorefingers23]

I've been switching the probe back and forth all day, between the carboys and they are both pretty much at the same temp.

 

[Conehead]

I use a thermowell in one carboy and just let the other one to hopefully do the same.

 

[TNJake]

I use a thermowell in one carboy and just let the other one to hopefully do the same.

+1 this

 

[SundayBrewer]

As long as they're both at the same level the taped probe is good

 

[day_trippr]

My BrewPi controllers don't use their Room Temperature channels for anything other than charting, so the next 10g batch I do (should be this week) I will repurpose that channel to monitor the second carboy and see how close the two track. I also plan on doing a "strapped vs thermowelled" probe comparison at some point (gonna order the naked 1/4" ID 18" long well from @Bobby_M right now)...

Cheers!

 

[day_trippr]

Confession: I totally forgot about my own plan until one day post-pitch, but I've already found enough to be surprised.
Yesterday I brewed the one beer I simply must have on tap - a ~1.107 OG imperial chocolate stout (it's what puts me to sleep at night ) - and this morning the two carboys were chugging along nicely. It then dawned on me I wanted to re-purpose the Room Temperature probe to monitoring the second carboy.

First, to correlate the Room probe with the Beer probe, I positioned the former adjacent to the latter against the originally monitored carboy. Once the two probe readings converged I moved the Room probe to the second carboy using exactly the same insulating foam and velcro straps and positioned close to the same height along the carboy sidewall. Crappy pic here (shot with an ancient cell phone in my brewery - my bad )

It did not take long for divergence to appear. The differential has been averaging 0.8°F with the original carboy being the cooler of the two.
Green is the original carboy temperature, gray is the second carboy:

I don't have a solid hypothesis as to why, yet (just looked at this a few minutes ago), but some time this evening I'm going to physically swap the two carboys and see if there's sensitivity to position...

Cheers!

 

[day_trippr]

So, just to wrap this up: by re-checking probe correlation and swapping them back and forth a few times I eventually was able to figure out the two carboys actually were running about 1°F apart, with the one closest to the door running warmer than the one at the back wall.
Also, that my "stirring" fan had gone to Heaven some time back and I had totally missed it.

Gray vs green are the two carboys...

Cheers!