cooling 100L fermentation

[jaroporter]

hey just wondering if anyone has any thoughts on this plan/options.

i'm using a 10mm copper coil on a 50L keg to cool batches at the moment, using a cornelius cadet chiller (like a maxi).
with a coupla big (special) parties coming up we wanna temporarily step up ferments to 100L to cover it. managed to borrow a large stainless pot to ferment in but need to be able to cool it. given it's very temporary i'm keen to do this as cheap and easy as possible so thought about wrapping it in beerline then insulation (i have some armaflex sheets).

for the chiller recirculation:
the pump in the cadet is rated 15W, with a max flow of 1L/min and a max line length (of 15mm python i believe, connected to the 9,5mm chiller coil) of only 25m. sounds problematic.
other option would be a TS5 pump (12L/min) on one of the product coils, which is only 5/16", and would mean knocking up another pid unit.

for the coil:
i was thinking 50m of 3/8" would cover 1/3rd of the wort, and with enough length should transfer a good amount of cooling? but obviously there's going to be too much resistance to use that with the maxi pump?
should it be a larger bore coil like 1/2" anyways? is just 25m of 3/8" way too little?

most likely i'm gonna have to grab a reel of hose and do some trials anyways, but if anyone has any engineering thoughts or experience i'd be grateful to hear it!

[TheSumOfAllBeers]

I used 10m x 10mm copper tube on my 65L chronical, then jerry rigged some connections onto 3/8 beer line.

Hose clips and plastic tubing with 10mm internal diameter are very effective at coupling 10mm & 3/8 together.

The beer line will insulate and be less effective than copper, but it will be effective at controlling active fermentation.

For reference I used a solar pump in a coolbox ice bath, to keep the first beer under control.

That a solar pump through ~14m of tubing.

Insulation of the coolant lines is critical.

But I don't see a flaw in your plan.

It may struggle to crash cool or lager, but I doubt you will have a problem holding it at 17C during active fermentation.

Put a lot of effort into getting great contact between your 3/8 and the FV and then insulate it (the coil) with something that is easy to make airtight, with duck tape or whatever.

Then wrap that in armaflex. Use bungees or ratchet straps to get the armaflex snug before fully securing it: its harder to work with than thermawrap.

[Kev888]

Yes, surrounding the FV in beer line then insulation can work to maintain fermentation temperature, though 'crash' chilling may be more limited. Copper would be somewhat more effective for the same length, though good contact would be needed for maximum benefit - the wort itself is likely to be the limiting factor then, rather than transfer to the pot walls. Or immerse a shorter stainless coil in the wort; a loop or two would do, 5m would allow good crash chilling. The trug of cooled water (cooled by say a short copper coil immersed in the trug) is another option, if you have one big enough for the FV to sit in - not as practical for every day use but easy and cheap for a one-off.

I had trouble with a maxi pump and long lengths of coil, it just wasn't up to the pressure needed to maintain flow. So i immersed a small brown solar pump in the cold bath - its a 14w one so powerful enough, whilst not adding much heat. It is controlled by an STC-1000, doesn't seem to need a PID. The standard pump would likely work for the shorter coil options, but would still need controlling.

Though... if you're in the uk and it is autumn, could you find some location for the FV that only needed heating? Will you need heating anyway, for the cooler/latter stages of fermentation?

[jaroporter]

cheers guys. good to have some reassurance. shouldn't need to crash chill as i'm using a heavily flocculating yeast, and usually rack to kegs direct after primary is over (5-6 days). so this really is just for active fermentation. not having done this much before though i was unsure just how crazy it would go.. ! for those reasons i'm thinking (hoping) heating shouldn't be an issue with such a large volume. once in kegs they could always be brought inside for further conditioning.

i have wondered about bodging an immersion "cold finger" out of some old SS racking canes i have, or even a beerline coil if that would submerge and not be a complete sanitation nightmare? possibly not as i have got my airstone stuck on the end of some 3/8" thinking 'bout it.. ah, guess i can play around when i've got the gear, just main thing is i don't wanna order a big ol reel of it if 3/8" is obviously gonna be a problem size or something.
could always end up hacking it with glycol..

interesting to know you used an stc kev. i've got the chiller pump wired into a PID but am really not sure if 20m of coil will be enough for active fermentation.. (bout 12 loops, actually should cover 25% of the beer, where 50m would cover bout 70%)
using a spare stc for the ts5 rather than getting another PID would be handy. i was thinking overshooting might be an issue with this volume of beer (but for all my knowledge of thermal dynamics it could be the total opposite!).
what length did your maxi pump struggle with in practise?

appreciate the input to my ramblings!

[Kev888]

100L will warm up more during the vigorous stage but won't keep that heat long once it begins to wind down. You may get away with it in a warm room, but if you would normally need warming I wouldn't necessarily bank on the extra size making enough difference in the latter stages.

50m sounds excessive to me. You can space the coils out to cover more of the FV with shorter lengths; the insulation should stop the area between the coils leaking out much heat. Half a dozen coils in copper is enough to maintain fermentation temperature (and/or a meter or two would suffice for a stainless immersion coil). I've not really tested limits with beer line but you wouldn't need to cover every inch of wall.

[jaroporter]

okay that's cool to know, much appreciated. i'd love to be able to get away with using 20m and the chiller pump, 50m is just the next size reel up from 20m, guess i don't need to use it all!

yeah my copper coil is very efficient, but it's soldered on and battered into an oval shape for contact and has lots of dings to assist with "turbular flow"..
just trying to not overestimate the beerline's ability. but like you say perhaps it's the volume of beer that is going to be the main buffer here..

[Fil]

with an unrestricted return use 8mm id silicone hose as a simple friction fit n seal connection between 10mm and 3.8" tubing..

for better efficiency of chilling i would suggest using a SS hex coil you can immerse in the brew directly i use an ex-chest chiller product coil in my 80l fv

[Kev888]

Given whats been said about the pump capabilities and temporary/cheap nature of this, a short stainless immersion/product coil does sound like a much easier solution to me, too.

[jaroporter]

yeah the cornelius chiller does have a fair few product coils that are unused i did consider but they're pretty much all intertwined so to be a bıtch to get separated..

the beerline is only £25 for 50m, where stainless coils - or organ donors - seemed to start much higher.. however, ease of using chiller pump/pid already installed suggests i should perhaps scout around on the immersion option first. for only 20 more i could get some "life-lasting" "multi-purpose" brewbuilder shiney.. here we go..

again, have appreciated the input

[Kev888]

The cooler coils do come up occasionally at good prices, the remote/big coils are easy to stretch out, but the problem in this case I suspect is time for them to come up. Theres currently this one - longer than really wanted but may be within the abilities of your pump or could be shortened.

[jaroporter]

that looks great kev, my ebay skills are obviously lacking! much happier to take a punt on something like that. even if the chiller pump goes slow the superior cooling will cover active fermentation, and i could even circulate hot water around it for a few days at the end if really neccessary.

worst case scenario it looks perfect for a jockey box.. cheers!

[TheSumOfAllBeers]

If you need heating, a youngs heat belt will do for D-rests and the like, though you may want to consider soil heating cable instead.

If you need extended cold conditioning you can always do that in the keg, which I suspected you were doing anyway with your volume demands