Putting multiple beers in the same fermentation chamber

[tyrub42]

Hi everyone,

I usually ferment one batch at a time in my fermentation chamber with this general timeline:
-use the chiller to get the beer to around 35c/100f (lowest I can get it here)
-put beer in the fermentation chamber, tape my probe to the side of the fermenter, and set the temp controller to 0 until the beer reaches target temp (it can drop it about 3c/6f per hour, so this step lasts 5-6 hours)
-pitch yeast at slightly under my fermentation temp, set the temp control correctly, and attach my blowoff

In a few weeks, I want to do two batches, but I'm not sure what the best way to do this is. I was initially planning to do the first batch on saturday, following those steps above. However, I'm not sure what the best course of action is for the second batch. I could chill it to 35c/100f and then put in in my chamber while the other batch is actively fermenting (at 19c/66f), and hope that it reaches the same temp within 24 hours and then pitch. For those who have done multiple batches in the same fermentation chamber, is this how you do it, or would another method be better? I did think of a few other options, but they may be overkill:

Option2:
-chill the first batch but don't pitch yeast, then chill the second batch to fermentation temp and pitch both at the same time (so they're both actively fermenting together). If I do this, I can take the first batch out of the chamber for a few hours while the second batch chills at full blast. I'm strongly considering this option, as there would be a batch sitting without yeast for about 24h either way, but this way they are pitched together and fermenting together. This makes it easier to make sure they're both at proper temp, since I can only put my probe on one fermenter.

Option 3:
-do a double brew day. If I mill both sets of grains the night before and wake up at 8am, I can have the first batch in the fermenter by 2, then do a half-assed cleanup (no need for the boil pot to sparkle if I'm using it again in a few hours) and get the second batch in the fermenter around 8, then pitch around 1am. This would be exhausting but would get everything done in 1 day.

What do you guys think would be my best bet? BTW I'm using the same yeast in both batches and they're relatively similar gravities (one about 1.065 and one about 1.055), so on that front things are nice and simple. Thanks!

Best,
Tyler

 

[jack13]

Since you are doing these in rapid succession regardless (at most 1 day apart), then I'd choose whichever option is more convenient for you, as none will likely mess up either beer. There is a certain attraction to your Option 3, but it's certainly not necessary. It sounds like you've considered all the important factors.

Personally, I'd take Fermenter #1 out of the chamber to sit at room temp while Fermenter #2 cooled. I doubt a few hours of fermentation at a slightly elevated temp (I assume) that Ferm #1 would experience would make a difference. And that way neither one would sit for 24 hours. But honestly, your Option 2 may be slightly better for the reasons you stated; I just wouldn't have thought of it. More accurately, I wouldn't have thought to think about doing it in a better way.

 

[mongoose33]

I have a ferm chamber (refrigerator) large enough to hold two fermenters. I've done staggered batches, staggered by a couple days, using the same ferm chamber. I used two inkbird controllers and two heat mats to do this.

Batch 1 goes in the ferm chamber, and Inkbird 1 controls the temp of the batch as normal. As yeast is exothermic, i.e., producing heat, the refrigerator is cooling the beer as necessary.

Batch 2 goes in 2 days later, when fermentation of Batch 1 begins to slow. Inkbird 1 is now switched to batch 2, so as that fermentation ramps up, and as that yeast produces heat, Inkbird 1 can control the temp of that fermenting beer.

But Batch 1, now slowed, will be cooled too much by a refrigerator trying to cool the now very active Batch 2. So I use Inkbird 2 to control only the heat mat on Batch 1, so that when Batch 1 starts to get too cold (as a result of Inkbird 1 cooling to control temps on Batch 2), it can apply heat to Batch 1 as needed to keep it at temp.

The key is to have them offset enough that the first batch's fermentation has slowed, and as a result, the exothermic activity has slowed, too, reducing internal heat.

****

I'm not sure that this will work, exactly, if you space the beers only 1 day apart, though you could monitor closely and swap the temp probe to the most active batch as necessary. I think that probably would work.

****

Couple of pics showing the above:

 

[tyrub42]

Since you are doing these in rapid succession regardless (at most 1 day apart), then I'd choose whichever option is more convenient for you, as none will likely mess up either beer. There is a certain attraction to your Option 3, but it's certainly not necessary. It sounds like you've considered all the important factors.

Personally, I'd take Fermenter #1 out of the chamber to sit at room temp while Fermenter #2 cooled. I doubt a few hours of fermentation at a slightly elevated temp (I assume) that Ferm #1 would experience would make a difference. And that way neither one would sit for 24 hours. But honestly, your Option 2 may be slightly better for the reasons you stated; I just wouldn't have thought of it. More accurately, I wouldn't have thought to think about doing it in a better way.

Yeah as I was typing it out I started to get more and more into option 2 as well. The logic of course being that there's way less that could go wrong that way, since it keeps the batches fermenting in tandem and allows me to have them both at proper temp by Sunday night. It also lets me do one giant vitality starter to split between them, so I don't need to do that twice.

Same thoughts as you for option 3 as well; part of me feels like that's the obvious thing to do, but the other part of me thinks it's unnecessary to put in the work of two brew days in one day (especially since I never have big plans on Sunday either).

I guess at this point it's between option 2 and 3, and that will depend on my mood, but if I know what's good for me I'll go with 2 haha.

 

[tyrub42]

I have a ferm chamber (refrigerator) large enough to hold two fermenters. I've done staggered batches, staggered by a couple days, using the same ferm chamber. I used two inkbird controllers and two heat mats to do this.

Batch 1 goes in the ferm chamber, and Inkbird 1 controls the temp of the batch as normal. As yeast is exothermic, i.e., producing heat, the refrigerator is cooling the beer as necessary.

Batch 2 goes in 2 days later, when fermentation of Batch 1 begins to slow. Inkbird 1 is now switched to batch 2, so as that fermentation ramps up, and as that yeast produces heat, Inkbird 1 can control the temp of that fermenting beer.

But Batch 1, now slowed, will be cooled too much by a refrigerator trying to cool the now very active Batch 2. So I use Inkbird 2 to control only the heat mat on Batch 1, so that when Batch 1 starts to get too cold (as a result of Inkbird 1 cooling to control temps on Batch 2), it can apply heat to Batch 1 as needed to keep it at temp.

The key is to have them offset enough that the first batch's fermentation has slowed, and as a result, the exothermic activity has slowed, too, reducing internal heat.

****

I'm not sure that this will work, exactly, if you space the beers only 1 day apart, though you could monitor closely and swap the temp probe to the most active batch as necessary. I think that probably would work.

****

Couple of pics showing the above:

View attachment 639459 View attachment 639460 View attachment 639461

Thanks! I think with my shorter time frame the best way to play is to pitch at the same time, since I wouldn't be able to stagger by several days, but I had the same concern as you regarding yeast heating up the batches differently if I pitch at different times

 

[Beernik]

Any of those methods will work for you. The first is the most tenuous if you don’t have good air movement in your ferm chamber.

I used to do double brew days and mine didn’t last from 8am to 1am. More like noon to 8pm. There were times I was still going late at night but it was usually from a late start.

There are a lot of time efficiencies to it. Only one setup. Only one tear down.

The main trick is to clean as you go instead of waiting. You’ve got an hour to kill during the 1st’s boil. You use that time to clean all your mash gear. After you finish the 1st’s chill and transfer the the fermenter, you get the BK visibly clean. You clean all your chilling stuff for the 1st during the mash of the 2nd. You clean the mash gear for the 2nd and put it away during the boil of the 2nd.

By the time you finish transferring the second, you just clean the BK, clean the chilling equip, and put everything away.

 

[tyrub42]

Any of those methods will work for you. The first is the most tenuous if you don’t have good air movement in your ferm chamber.

I used to do double brew days and mine didn’t last from 8am to 1am. More like noon to 8pm.

There are a lot of time efficiencies to it. Only one setup. Only one tear down.

The main trick is to clean as you go instead of waiting. You’ve got an hour to kill during the 1st’s boil. You use that time to clean all your mash gear. After you finish the 1st’s chill and transfer the the fermenter, you get the BK visibly clean. You clean all your chilling stuff for the 1st during the mash of the 2nd. You clean the mash gear for the 2nd and put it away during the boil of the 2nd.

By the time you finish transferring the second, you just clean the BK, clean the chilling equip, and put everything away.

When you put it that way, it does seem really appealing to do it that way. I don't have a fan in my chamber (yet) so 2 or 3 are probably my best choices. I guess between those it's not really a big deal either way, and will just depend on whether or not I'm feeling up to the double brew day at the time. Thanks for the insight!

 

[gnef]

If you are looking at efficiency, a double brewday can do that for you, as you can mash the second while boiling the first. It is a long and arduous day, but you save a considerable amount of time in total, and you can then also keep everything on the same daily schedule, which makes things simpler in my mind too. When I was doing double brew days, it would only extend my total time by about a third - essentially the time to lauter and boil if you time things well.

So, if you have the time and energy, do a double brew day, and map out how to stagger the timing so that you can increase your efficiency.

Also, don't start drinking until you chill the second batch, otherwise you will be much more likely to make mistakes and turn the brewday into an incredibly long brewday.

 

[tyrub42]

I finished the two brews and they are both happily bubbling away. I went with option 2 and it worked perfectly so far. I chilled the first brew to about 15 degrees f lower than pitch temp, so it would have a little buffer when I took it out of the chamber to chill the second batch. I kept temps monitored and when they were even, I put it back with the other fermenter in the chamber and they both proceeded to reach pitching temp together. I propped up a double dose of second-generation Nottingham slurry the morning of the second brew in a vitality starter, and pitched halves into the two brews. Fermentation had begun 10 hours later when I went to work and they both developed their krausens in unison. Judging from the outside readings on the fermenters, they've been within 1 degree f from one another during active fermentation which is great.

Overall, it was a cool experiment and one I may start to do more often. I tried to post pics from my phone but for some reason homebrewtalk doesn't work for posting from my phone. I just started an instagram for brewing stuff, beer stuff, and cat stuff. You're welcome to check out pics there if you'd like (IG name: beer and cats).

I'll update with how the batches turn out, but so far it seems like everything has been optimal . Thanks for the feedback on this!!!

Best,
Tyler

 

[jjw5015]

Not sure what styles you are making, but kveik yeast is great for not having temp control. Very clean yeast with temp range upwards of 100 degrees

 

[DVCNick]

I think that is what I would have done too.
It takes my chest freezer about 5-6 hours if I remember right, to chill a five gallon batch from ~110 to 70. If I had another batch in there already I would definitely take it out, as it would get way too cold chilling for 5 hours straight. I probably wouldn't even worry about trying to drop the temp extra beforehand. There is a lot of thermal mass in 5 gallons, and it just isn't going to move all that much in 5 hours at room temp. 15 degrees, I bet is very excessive there. I just take it out, throw it back in when the second batch was ready, and it would be at the ideal temp quickly after that (assuming you want them both at the same temp).

Also, fridges and freezers are either on or off. No reason to set your temp controller to zero; it isn't going to cool it any faster, and you'll have to watch it closely to not overshoot. Just set it to the temp you want and come back in a few hours and it will be there.

 

[kevin58]

Use Kveik yeast in the second and go ahead and pitch hot.

 

[9Kegs]

I ferment 3 batches (3 gallons) at a time in my chamber following a triple batch brew day.. The key is to use yeast with similar temperature ranges or different styles that can use the same yeast. To shorten my day I use 2 kettles , 2 cooler mash tuns and leapfrog my process. Setup water in both kettles and mash in each cooler when ready. Now I have 2 empty kettles, one for boiling wort and the other for setting up strike water for 3rd and final mash. Drain 1st cooler to boil kettle and start boil. Cooler is now free for final mash. Transfer strike water to final mash which also frees up your 2nd batch boil kettle. Transfer 2nd mash to boil kettle. I boil 1st batch on strongest burner while heating 2nd batch almost to boil. This staggers my process which works well with only 1 chiller. I try to keep each batch on deck for its next step. I set my chamber for my starting temp and let the probe hang free inside. I try to get the wort close to starting temps before pitching yeast but this summer high 60's was lowest achievable. Final batch has a thermowell for the temp probe. What I have found is that the temp in all 3 reaches a close equilibrium within a day. My brew day including cleanup has been shortened from 12 plus hours to less than 8.

 

[tyrub42]

I think that is what I would have done too.
It takes my chest freezer about 5-6 hours if I remember right, to chill a five gallon batch from ~110 to 70. If I had another batch in there already I would definitely take it out, as it would get way too cold chilling for 5 hours straight. I probably wouldn't even worry about trying to drop the temp extra beforehand. There is a lot of thermal mass in 5 gallons, and it just isn't going to move all that much in 5 hours at room temp. 15 degrees, I bet is very excessive there. I just take it out, throw it back in when the second batch was ready, and it would be at the ideal temp quickly after that (assuming you want them both at the same temp).

Also, fridges and freezers are either on or off. No reason to set your temp controller to zero; it isn't going to cool it any faster, and you'll have to watch it closely to not overshoot. Just set it to the temp you want and come back in a few hours and it will be there.

My apartment is super hot (Taiwan rooftop apartment in August), so 15 wasn't enough surprisingly. In a normal 75-degree apartment in the US I wouldn't do anything close to that.

Re: temp control. I have my probe taped to the outside of a plastic fermenter, so when the freezer is at -xx degrees it affects sensor readings. That's the only reason I set it to lower than my desired wort temp. Once wort reaches pitching temp and the freezer isn't on continuously, the probe reliably reads 1-2 degree lower than inside temp.

Thanks!

 

[tyrub42]

Not sure what styles you are making, but kveik yeast is great for not having temp control. Very clean yeast with temp range upwards of 100 degrees

I'm probably in the vast minority but I'm not a big kviek fan for the most part. I've done a few batches with hothead. One was great and two were ok at best. The great one was a winner but would have been as good or better with London iii or Juice. I feel like it's not as clean as advertised, and attenuation isn't amazing.

I'm definitely not a hater, though. I appreciate the fact that it makes a lot more styles accessible to Homebrewers who can't afford a temp control, but considering how cheap you can usually find a used fridge or freezer, I still like to think it's affordable enough for most. Plus I've had a few hoppy kvieks that have a scratchy feeling, likely from hop matter left floating around because they weren't cold crashed.

Idk, unless I needed a 5-day GTG beer I don't think I'd use it again. Otherwise the one that worked well was designed to lean into the esters and worked great. 6 percent abv juicy pale with citra and Mosaic. 24 hour dry hop before cold crashing; pale, wheat, oats; low mash temp to finish at 1.012. Overall I liked the mouthfeel more with London iii but the esters in both make a nice juicy beer. Hornidal (I think that's the name...the other one besides hothead that's equally popular) had a profile I liked a lot in a friend's beer. It just seems like there are a lot more misses than hits with the kvieks I've had from Homebrewers and the few commercial examples I've had, compared with traditional yeasts.

Sorry for this novel of a reply! Just got off a long day of work and feeling kinda Spacey haha.

 

[tyrub42]

I ferment 3 batches (3 gallons) at a time in my chamber following a triple batch brew day.. The key is to use yeast with similar temperature ranges or different styles that can use the same yeast. To shorten my day I use 2 kettles , 2 cooler mash tuns and leapfrog my process. Setup water in both kettles and mash in each cooler when ready. Now I have 2 empty kettles, one for boiling wort and the other for setting up strike water for 3rd and final mash. Drain 1st cooler to boil kettle and start boil. Cooler is now free for final mash. Transfer strike water to final mash which also frees up your 2nd batch boil kettle. Transfer 2nd mash to boil kettle. I boil 1st batch on strongest burner while heating 2nd batch almost to boil. This staggers my process which works well with only 1 chiller. I try to keep each batch on deck for its next step. I set my chamber for my starting temp and let the probe hang free inside. I try to get the wort close to starting temps before pitching yeast but this summer high 60's was lowest achievable. Final batch has a thermowell for the temp probe. What I have found is that the temp in all 3 reaches a close equilibrium within a day. My brew day including cleanup has been shortened from 12 plus hours to less than 8.

Wow triple brew day! Sounds like you've got your process dialed in perfectly to pull that off.

Totally agree about the yeast; must've forgotten to mention it. These two were both Nottingham and pitched from the same starter so they took off together. Og wasn't exactly the same but it was only 7 points off I think (not that it's impossible to do different ogs together but the higher one would probably get a bit hotter during peak fermentation I think). I'm doing another double next month with London iii in a hbc-472 stout and a DIPA. Those OGs would be a bit father apart but probably still only 10 points. Those are just what I feel like drinking ATM so it could change. Have you ever done three batches with very different OGs together and if so, have you noticed any difference?

Thanks!

 

[9Kegs]

Have you ever done three batches with very different OGs together and if so, have you noticed any difference?

My OG's are pretty close so I can't help you there.

 

[Beer666]

I ferment lagers in a tall fridge. If I set the top shelf fv to 10c with a sensor taped onto it the bottom shelf is approximately 2c warmer. I chill the wort to about 40c then put it in a cube. I feel there is less oxygen exposure and it can sit in there for days if necessary.