Keep it cool

I was wondering if a sake fermentation could be kept cool using a stainless steel immersion chiller?

Since the temp only needs to be between 46-50F I’m thinking this could work. The idea is to use an 80 gallon open top flextank and a small glycol chiller hooked up to a stainless steel immersion chiller coil thing. I would use a temp controller to turn the chiller on and off and the tank would have insulation material wrapped around it. Do you think this could work when ambient temps are 75-80F? The concept is sort of like…instead of sticking the tank inside the fridge…we’re actually sticking the fridge inside of the tank. Does this make sense? Would it be better to wrap the coil around the outside of the tank?

I’m trying to figure a way around using expensive jacketed stainless. Any ideas?


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I wouldn’t see why not, other than risking more surface area to contamination potential with the coils.
Could just wrap the outside of the stainless fermenter with copper coils, add copper wool (like steel wool but copper) under the coils and then wrap the whole thing with insulation. The pump coolant on the outside.

Thanks Dray! I’m think this could work. I might just use regular water and an aquarium chiller in lieu of a glycol system. I think the coil could be well sterilized using boiling water prior to fermentation.

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What’s the internal volume of the coil? It may (or may not) be worthwhile to also consider something to move the contents of the barrel around, more than natural processes do. That way, you wouldn’t have any “cold spots” so to speak, and your whole batch would be more consistent. Don’t ask me how though. If you could sanitize (and make food safe) what plumbers call a garbage pump, as pursuant to the presence of solids, that might do it.

I appreciate the point you make about “cold spots”. However, any type of cooling system will have those, even insulated jacketed fermenters have cold spots along the walls. I think the fact that sake is stirred often throughout the fermentation will help to mitigate that issue though.

Math time…

V = π(r^[size=85]2[/size])h
= 3.14 (0.15"^2) (600")
= 42.14 cu. in

The internal volume of the coil is around 42 cu inches (0.18 gal) for a 50’ long coil.

As far as the garbage pump is concerned, cool idea, but I don’t think I’ll be attempting to use anything like that.

I’m a bit late to this thread… anyhow, you know my approach MPF, I do 50’ of 3/8 refrigeration copper around the outside of the tank, which carries glycol pumped around 35F. I never have ambient temps as high as yours (75-80), and I still found I needed a low glycol temp to maintain appropriate temps throughout the tank. So I would be interested in hearing about how the immersion chiller goes. I’m certain your idea would work, but I still think I made the right choice.

I considered an inside coil when I was building my tank, the efficiency benefit seemed obvious since 100% of the coil touches the juice, but decided against it for the sake of ease-of-cleaning. I’ll never have to touch that coil again, which is warm fuzziness to me. I just empty the tank and clean it out, done.

Plus it’d nice to not have to worry about that mess of metal inside when you’re mixing and adding. A final point, I find it beneficial with a large batch of sake, as the foam recedes, to scrape the walls of the fermenter before the foam dries and starts smelling. That would be harder with the immersion chiller, since it too could be foam covered (if above the liquid level). You could always pull it out and clean it periodically, I guess.

Keep us updated on your progress, I’m certainly interested.

Yeah, I’m just trying to think of ways to control larger tanks of fermenting sake cheaply and effectively. However, I think I will most likely have to resort to glycol and jacketed tanks. I’m trying to factor in what a chiller would cost too. Could get spendy fast depending on how big of a system I want to go with.

There is also the possibility of using a

. It might be easier to clean.

Pdarling, what are the specs on your glycol chiller? I’ve read that for cooling coils on the outside it is very important that the copper be absolutely in contact with the fv to be efficient. Did you find that this was fairly easy to accomplish? I like Dray’s idea of using copper wool as a buffer between the coil and the tank.

I like that cooling plate. Seems like the way to go for immersion cooling.

My chiller is a Perlick 4204PRUL. It draws around 5 amps for the compressor and has a 5 gallon reservoir. When I wrapped the copper, I used ratchet straps with a strong spring attached to crank it tight then went around it with a rubber mallet, making the tube slightly ovoid in spots.

Afterwards, I silicone caulked where the tube met the stainless. After some research I decided silicone conducted better than air and would help keep it tight. I do like dray’s idea with the copper wool. Oh and the day before, I used jb weld to anchor the start of the coil, which helped. The project wasn’t too hard, a full day with a buddy helping.

I think my problem with keeping it cool was due, largely, to the tank being uninsulated. My intention was to eventually have ambient temps keep the tank cold, so I figured that would be easier without insulation. I thought the chiller would have no problems, but apparently it struggled.

Now, however, the tank is covered in spray foam and I think my problem with keeping cool will be gone. I’ll find out here in a week or so when my moto is ready. :slight_smile:

PD, thanks for sharing the build / specs on that set up of yours. It’s good to hear that you are starting another batch of sake too!

I found another possibility for cooling non-jacketed tanks. Seems like a legit concept:

I like these bands because you can put them right where you need the cooling capacity. Part of the problem I am encountering when looking at jacketed tanks concerns the jacket placement. Most of them are too high up and wouldn’t be effective prior to nakazoe addition.

What do you think?

Yeah, looks like a great option to me. Having those mobile zones with undoubtedly help. Plus you’d retain the ability to tinker with the design.

I ran into problems chilling small quantities in my tank, it takes around 4 gallons before the coil starts, due to the dish shape at the bottom. Also, up high where the coil touches the tank but not the moromi level, I get condensation dripping on the inside. No biggie, just saying.