DIY Chiller

[akom]

We are a micro kombucha brewery based in the UK. We are in the process of switching from natural carbonation (in the bottle) to force carbonating.

To do this we are going to purchase a 500 litre brite tank. We are now looking at ways to keep it cold (on a budget!).

We have a walk in freezer with lots of spare space so I wondered if filling a large barrel (up to 150 litres) with glycol and pumping that around the brite tank would work?

The freezer is always -18 to -20 degrees celsius. We would ideally like to get the kombucha down to around 3 degrees.

Does anyone know if this would work? If so, how much glycol would we need? I also found a youtube video where someone did something similar but also had the glycol run through an immersion coil in ice before returning to the glycol reservoir so this would be an option as well.

[dick murton]

I think you will suffer from two things - firstly, and perhaps most critically, icing on the inside of your tank, due to the extreme temperature difference. We used to produce a so called ice beer, with glycol at - 5, to deliberately build up an ice layer - so minus 18 is going to build up a layer of ice very rapidly. Secondly, you have virtually no recirculation currents, so the inside is likely to remain above your target temperature for quite some time.

I suggest you get hold of a pub chiller, and well insulated bright tank, and have internal cooling coils or panels with glycol / chilled water at about - 1 or 2 C at the coldest, or more expensively, a plate chiller with recirculation pump.

As I understand it, kombucha is about 1 % alcohol, or less so you do not need a liquor licence to sell it, and can freely sell it to under 18s, so the freezing point is going to be about zero C - so you can't afford a temperature difference of more than about 2 degrees C with static coils or panels. And don't forget if you have panels or coils, you must make sure everything is easily cleanable and sterilisable - not so easy as a simple tank.

[akom]

Thanks for the info.

We also have a walk-in fridge. We have some spare space in it though not enough to put the brite tanks in. It is 2-3 degrees Celsius.

Would it work using this for the glycol (or I guess water would work in this case?)?

So we’d have a 500 litre jacketed brite tank with glycol or water pumped around it from the fridge?

Or will pumping it around the jacket take forever? We’d prefer to use the brite tank jacket as opposed to immersed coils.

We were hoping to chill it in about 24 hours but we have zero experience with this so not sure if that is realistic. Even if we could only get the temperature down to 4 or 5 degrees I believe this would be sufficient as we should be able to carbonate at that temperature.

[dick murton]

I'd get hold of a pub chiller used for cooling pythons or similar. With so many pubs closing each week, there must be loads of them going virtually begging. If nothing else, try contacting someone like Innserve. I don't think brand new ones are too expensive either, but afraid I really don't know how much. Perhaps you can get hold of a copy of Morning Advertiser from a tame publican. Failing that, Some of the brewing equipment suppliers use them - Fabdec for one (try Dave Marsh or Mark Madeley), and Ninkasi tank rentals supply new chillers with their rental tanks, (try Andrew Taylor).

Cooling the glycol in a fridge will be incredibly inefficient. A jacketed and insulated tank is the best option - far better than internal cooling coils, though internal ones work well - just a bit more trouble to clean.

Look at the classifies on the SIBA website - there is a Moravek 2 head filler going at present, which comes with built in, in-line carbonator, and a separate BBT - good stuff the Moravek. There may be other stuff, but I haven't gone back very far recently - but bear in mind I get the impression people are not good at telling SIBA they have sold stuff, so a lot may already be sold.