Cold crashing kombucha

Question

Does cold crashing kombucha work in terms of removing yeast and creating a brighter product?

I am using a continuous brew process where I decant from the primary fermenter in to a secondary fermenter where I add fresh ingredients to infuse flavor. After removing the ingredients I was wondering if I could use a glycol chiller to drop the yeast similar to what I'm reading about beer. I'm not a huge fan of cloudy kombucha with a pile of sediment on the bottom of the bottle/glass - so I'd love to solve that.

I'm doing the second ferment in a brite tank now since it's an anaerobic process and it's where I get the carbonation. I can easily add a chiller to the tank, so I was thinking of trying it. Just wondered if anyone had experience or an educated guess as to the outcome.

Answer 1

In my personal experience, cold crashing does help to clear the booch a bit.

I'm a homebrewer who has started to brew kombucha. I've only got 4 kombucha brews under my belt and I've been kegging since my 2nd batch. After a day our 2 in the keg (and a cloudy pour or 2) the kombucha is very clear and has a hint of color from the fruit used. This is also common with homebrewed beer as the yeast and proteins in the kegged product tend to settle to the bottom of the keg at cold temperatures.

Note that I'm using a similar brew process to you. I hope to have the time to document all of this with a blog post at some point in the future.

I should also note that I brew in a fermenter with a conical bottom. When I rack the kombucha, I pull it from above the cone, so there is a decent amount of yeast/sediment left behind. I brew and add fruit in one vessel and then transfer to the keg.

Comment added to answer per suggestion above.

Answer 2

Some info about Cold Crashing.

Cold crashing will definitely help that problem of cloudiness and yeast sediments on the bottom. I recommend 10 days at as close to 0 celsius as you can. e.g. 1 degree celsius.

Cold crashing will make most of the yeast flocculate (clump together and fall to the bottom.) and they will hibernate in the cold. However, cold crashing will not completely remove the yeast.

There are several methods to remove or kill the yeast.

1. Pasteurization

Heat up the liquid to 80 degree's celcius for 15 minutes, and cool down. This will kill all the yeast and they all will eventually flocculate.

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2. Filter

Like normal lager beer you get in the store, you could filter your kombucha to remove any yeast or haze. See this video for a how-to. https://www.youtube.com/watch?v=YOclJsjZnyY

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3. Fining Agents

You can also use fining agents to clear your kombucha. This is generally used for wine making, (especially isinglass, bentonite, gelatin, pectolyase, kieselsol).

Substances such as finings include egg whites, blood, milk, isinglass, and Irish moss. These are still used by some producers, but more modern substances have also been introduced and are more widely used, including bentonite, gelatin, casein, carrageenan, alginate, diatomaceous earth, pectinase, pectolyase, PVPP, kieselsol (colloidal silica), copper sulfate, dried albumen, hydrated yeast, and activated carbon

However, clearing your kombucha to become like a clear white wine, kind of defeats the purpose of kombucha. A part of the definition of kombucha is to have yeast cells in it.

Back to Cold Crashing your Kombucha

How to prevent yeast sediments in the glass.

1. I would recommend Cold Crashing the kombucha for minimum 3 days before bottling it.

2. Tap the kombucha in bottles, or in a barrel, and let it stay cold at least 1 day before you serve it.

3. Be careful when pouring the kombucha in your glass. A good pouring-technique will prevent you from having sediments in your glass.