Multiple fermentations in a single fridge

[count-ant]

Hey all,

I'm looking at purchasing a fermentation fridge/freezer (haven't decided yet). I'm considering buying something which fits 2 fermenters at once. My question is.. what downsides are there if I'm trying to ferment two batches at different stages of fermentation with likely different preferred ranges?

Thanks!

 

[Camo6]

No down sides.You can produce twice as much beer. Just ferment them at the same temp.

If you really want to get pedantic, you could look into where you place your heating device and which vessel get's the probe. The bottom of the fridge will be cooler but is a better spot for a heat pad or similar. I place my heat pad down the lower side of my fridge and place my temp sensor on the upper fermentor. Then I circulate the air with a PC fan. About as scientific as I need it to be.

If you're going to stagger your ferments by more than a few days, you're probably better moving the probe to the new fermentor to give more stable temps in the early stages of fermentation.

But really, the ability to ferment more beer at the same time shouldn't be something that requires deliberation.

What would Shia do?

 

[Coodgee]

You've got to do a bit of juggling. If you do a double batch then they should be at the same temp when you pitch the yeast and then all is fine; The two should stay fairly even throughout the ferment.

But say you have one fermenting at 18 for a few days and you add another fermenter a few days later, you'll have to take the first one out, swap the temp probe to the new one and chill that brew down to 18 and then put the first fermenter back in the fridge. If you put a 25 degree brew in with an 18 degree brew they won't just equalise at 18 straight away. I have found they can maintain a stuborn differential for ages. especially if you have a new beer firing at full krausen and another that is nearly done.

 

[Black Devil Dog]

KISS. ( Not the Band, they're ****) Keep It Simple Superdude.

Just ferment the same styles, at the same time, in the same fridge.

 

[Mr B]

Yep no probems, I did it for ages.

If you start two batches at the same time, you can crash them both if you want to.

If you start a batch fermenting when another is already going, if you no chill just put the cube in there for a day or so to get it to pitching temp.

If you already have one batch part way through ferment, put the temp probe on the new batch as it will run a little warmer (but not enough to affect the one part way through)

I had a second fridge that I put a batch into to crash chill.

Plenty of options, all doable.

Most ale or lager yeasts will prefer a similar temp range (but about 18 deg for ales and 11 or so for lagers), so you will basically have a choice of ales or lagers at the one time.

 

[manticle]

Downside is you can't ferment a belgian saison and lager a dunkel at the same time but that should be obvious.

Otherwise it's down to you and planning

 

[cliffo]

I brew two batches at a time and ferment both in the same fridge.

Apart from the constraints of having to use yeast strains that like a similar temperature range I've never had any issues.

 

[mtb]

I've gotta wonder about that temperature differential, between a part-way fermented batch and a batch at high krausen. I know high krausen batch would produce more heat, but if circulating within the chamber with a fan, wouldn't much of the heat be drawn off and distributed? I currently have four SS kegmenters running two separate batches and now you guys have me worried about temp differentials

 

[count-ant]

Thanks everyone for your replies, really helpful. The overwhelming advice seems to be to just get a fridge that can do both and don't be an ***** trying to brew a saison and lager

I'm hoping to do either split batch with different types of yeast and maybe secondary fermentations (eg. standard stout and a coffee/choc stout or something), or have two different ale batches on the go and split the difference in ideal temp range for fermentation. Does seem that I'm best off either starting both batches at the same time to eliminate high activity temp differences.

.. now to go try find a fridge that can take two brewbucket minis

 

[2cranky]

I got a fan forced freezer. I was able to remove all the shelves and put new ones where I needed to hold 2 fermenters. The fan works well to keep the temps even.
the reason I went for a freezer rather than fridge was because I thought that an old fridge might not cold crash that well. The freezer works great - easily crashes to 2c.
A lot of the upright freezers have the cooling lines in the shelves so you got to watch that as you can't remove those shelves.
My last 2 batches were a 6.5% IPA with a 4.4% stout. The stout was all done in 5 days so I just removed it and kegged warm. The IPA is going through the dry hopping stage at 14c, then cold crash to 5c for Gel, then cold crash to 2c and keg. Couldn't see any point for the stout to go on that ride!

 

[count-ant]

I got a fan forced freezer. I was able to remove all the shelves and put new ones where I needed to hold 2 fermenters. The fan works well to keep the temps even.
the reason I went for a freezer rather than fridge was because I thought that an old fridge might not cold crash that well. The freezer works great - easily crashes to 2c.
A lot of the upright freezers have the cooling lines in the shelves so you got to watch that as you can't remove those shelves.
My last 2 batches were a 6.5% IPA with a 4.4% stout. The stout was all done in 5 days so I just removed it and kegged warm. The IPA is going through the dry hopping stage at 14c, then cold crash to 5c for Gel, then cold crash to 2c and keg. Couldn't see any point for the stout to go on that ride!

Does a fan forced freezer also have less moisture issues or is that something all freezers at non freezing temps deal with?

 

[Mikeyr]

And if you don't have a 2nd brew you have a nice temp controlled space to be building your 2 litre starter at the right temp. Or cool down the cube to the right temp ..... bloody weather ... 25C ...

 

[2cranky]

Does a fan forced freezer also have less moisture issues or is that something all freezers at non freezing temps deal with?

dont have any moisture issues. well not since i got a heat belt and stopped using open trays of hot water in there to raise the temp!

 

[Mr B]

Does a fan forced freezer also have less moisture issues or is that something all freezers at non freezing temps deal with?

Not sure about a difference with moisture levels, but I ended up with a mould problem in my main ferment fridge.

Recently gave it a bleach and now have moisture absorber in there. So far so good.

 

[Judanero]

No problems but will take planning. As previously mentioned you will struggle to get a saison and a lager in the same fridge, but ales in the 18-21c range, no probs.
Use something like the San fran lager yeast (WL) as your house yeast and you could do lagers and ales in the same fridge (starting with ale and then adding in the lager as you drop the temp).

Keeping in mind the lager would then occupy your fridge for a bit before you could re-introduce an ale.

 

[mstrelan]

f you really want to get pedantic, you could look into where you place your heating device and which vessel get's the probe. The bottom of the fridge will be cooler but is a better spot for a heat pad or similar. I place my heat pad down the lower side of my fridge and place my temp sensor on the upper fermentor. Then I circulate the air with a PC fan. About as scientific as I need it to be.

I thought the bottom of the fridge should be cooler, so when cold crashing I put the temp probe on the bottom fermenter set to 1C. The top fermenter froze and the bottom one didn't. I guess the cold air comes from the top.

 

[Camo6]

I thought the bottom of the fridge should be cooler, so when cold crashing I put the temp probe on the bottom fermenter set to 1C. The top fermenter froze and the bottom one didn't. I guess the cold air comes from the top.

Most freezers have the evaporator at the top and cool air circulates down. For ferment temps I like to measure the top vessel because I would rather the one without the probe to stay cooler not warmer.
But when you cold crash the freezer/fridge will run flat out so there will be cold air constantly passing the top fermentor. To combat this I usually do a couple of things.
One is to leave the probe to measure the actual fridge or freezer chamber. It will cycle the compressor more but should reduce the chance of one vessel freezing.
I also CC in stages as trying to hit 1c in one step will cause your airlocks to freeze and either draw air in through the seals or collapse the vessel ( or suck in water if using a blow off). Usually 5-8 degrees per step over a couple of days.
Another method I also employ is to swap the blow off tubes or airlocks for steri-locks when I CC. These little filters are pretty useless during the ferment stage but seem to work well enough when reducing temps with no chance of freezing or drawing from the blow off bottle.
Hmm. Maybe I have actually thought about this before.

 

[count-ant]

Most freezers have the evaporator at the top and cool air circulates down. For ferment temps I like to measure the top vessel because I would rather the one without the probe to stay cooler not warmer.
But when you cold crash the freezer/fridge will run flat out so there will be cold air constantly passing the top fermentor. To combat this I usually do a couple of things.
One is to leave the probe to measure the actual fridge or freezer chamber. It will cycle the compressor more but should reduce the chance of one vessel freezing.
I also CC in stages as trying to hit 1c in one step will cause your airlocks to freeze and either draw air in through the seals or collapse the vessel ( or suck in water if using a blow off). Usually 5-8 degrees per step over a couple of days.
Another method I also employ is to swap the blow off tubes or airlocks for steri-locks when I CC. These little filters are pretty useless during the ferment stage but seem to work well enough when reducing temps with no chance of freezing or drawing from the blow off bottle.
Hmm. Maybe I have actually thought about this before.

Cheers for the response mate, good tip about the cold crashing. Especially with nice shiny stainless, not looking to go warping the sides inwards >.<

It's almost like there is more than one way to skin a cat, so much for the perfect answer haha

 

[manticle]

Don't skin my cats

 

[bradsbrew]

I am going to have a lager and and ale fermenting at the same time.

Fermentasaurus with a lager yeast.
MJ SS fermenter with ale yeast.

Both brews will be pitched at the same time. I would not have belived i could do this a couple of months ago, the fsaurus is a true game changer.


The fridge will be set at 16 for 3 days then 18 for 3 days. Once both are done - cold crash.