Fermenting 2 different beers at the same time

[sorefingers23]

Hi everyone, I've been wondering about this for a while, I built a fermentation chamber than can hold 2 carboys and am wondering if I was to brew a 10 gallon batch, or brew 2 beers on the same day, or even one on a Friday, and another on the Saturday, could I ferment both at the same time in the same fridge. Right now I put my carboy in, tape the probe to the side wuth some insulation. If I put 2 in how would I control the temp for 2 beets at different stages of fermentation? Would it be best to not use the probe and just set the chamber to a certain temp? Or just keep doing it 1 at a time ?
Thanks

 

[jlinz]

Hi everyone, I've been wondering about this for a while, I built a fermentation chamber than can hold 2 carboys and am wondering if I was to brew a 10 gallon batch, or brew 2 beers on the same day, or even one on a Friday, and another on the Saturday, could I ferment both at the same time in the same fridge. Right now I put my carboy in, tape the probe to the side wuth some insulation. If I put 2 in how would I control the temp for 2 beets at different stages of fermentation? Would it be best to not use the probe and just set the chamber to a certain temp? Or just keep doing it 1 at a time ?
Thanks

The stages of fermentation wont matter. You would just have to ferment both beers at the same temp. Anyway, I don't see a problem with that. You could put the probe on a single carboy or not, doesn't matter unless you are trying to be absolutely correct temp wise. I'm not quite that rigid myself.

 

[Jtk78]

I would be mindful that if you put fermenter A in on Sunday and set temp to 68F with probe taped to side and insulated, then put fermenter B in the following Saturday but do not swap the probe, the actual temp of wort B will probably be higher than the 68F. I would recommend putting it on the new vessel.

That being said, I usually do two batches in one day and just put the probe on one vessel. You need to make sure if your using different yeast they have similar temperature ranges.

 

[mongoose33]

If you brew two batches at the same time, same recipe, same yeast, then I don't see any reason why you couldn't do that.

The problem with staggered batches, and it is even more an issue with different recipes/yeasts, is that the temperature increase from the exothermic action of the yeast will differ by batch.

Suppose you put the temp probe on Batch A, started on Friday, set to control its temp at 66. Then you do Batch B on Sunday. When Batch A finishes active fermentation, there will be little added heat from the yeast. But Batch B is still going to town, so the Batch B fermenter will have temps higher than Batch A.

If you can stagger the batches by 3 days, it is possible to have both going at the same time, but it requires two controllers (I use Inkbirds). One is set to control cooling, one is set to control heating.

You start w/ one batch, control it via cooling. After 3 days or so, add the second batch to the ferm chamber and switch the probe to it. BUT, also have a heating device (Fermwrap, reptile cage heat mat, whatever) on the first batch, and control that with a second Inkbird.

Since the ferm chamber has to cool the second batch during its active fermentation, it'll cool the first batch too much. So the second Inkbird adds heat back to Batch A to offset this effect.

I did a thread on this about a month ago. You may be able to adapt the ideas to your specific situation:

https://www.homebrewtalk.com/showthread.php?t=631776

 

[xico]

What mongoose said, beat me to it.

Volume can also play a role in slight changes in temps. A 3 gallon batch will cool faster than a 5 gallon batch. I often press the probe between two ferementers and weatherstripping over the tip not in contact with anything. It helps to split the difference slightly.

If you find you have the means to pick up a laser thermometer (I got mine for 10 bucks on a sale) I would note the differences in probe along with each carboy. This information will help you learn how to get the most use out of the chamber. I know I can put the probe in my sanke fermenter active in primary fermentation and my corny fermenters will sit at a couple degrees cooler and plan for this.

If you want them to ferment at the same time you could crash the first batch to 1C, ~34F and when you start your brew day you warm the vessel up and pitch when the temps of both batches meet. Please share your findings if you can and it will help someone else down the line.

 

[MHBT]

what im thinking is if you have batch A fermenting at 66F for example with the probe either taped or thermowell and you want to brew batch B and put it in the same chamber just chill/pitch batch B lower say 3-5 degrees and by the time it warms up it should be matching batch A in temps and the chamber cooling cycle.IDK im trying to figure out best way to ferment 2 beer at the same time also