Kombucha / Beer in Same Fermenter

[JWR_12]

Hi! So I'm wondering if anyone has any experience alternating between brewing beer and kombucha in a stainless steel conical fermenter. I've heard you shouldn't try to brew e.g. sour beers in the same equipment as regular beer, because of potential cross contamination. Assuming a good cleaning between uses, would Kombucha critters end up in the beer or vice versa?

 

[Minbari]

@GFHomebrew make kombucha. He might be able to answer that

Depends how you sour it. Preboil bacteria would ok. Post ferm Brett. You would want dedicated stuff

 

[GFHomebrew]

Na I keep the bootch separate from my fermenter.

You must make a fair wack of Kombucha?

 

[Donoroto]

It is possible but the fermenter should be sterilized, not just sanitized, between beer and booch in my uninformed opinion. Iodophor after an exceptionally thorough cleaning should suffice.

 

[Sunfire96]

The stainless steel should be fine, but any rubber gaskets and parts, as well as the spigot won't be properly sanitized between batches. Kombucha scoby isn't just one strain of yeast or bacteria, it's a complicated biome with multiple competing species. I would be very hesitant to use the same vessel for beer, the risk for contamination is very high.

 

[Mark Farrall]

Can you get a process that kills 100% of the microbes from the previous batch? It's not that they're harder to kill than standard sacchromyces (many are much easier to kill), it's just that if you miss a few, they're far more likely to change the taste of your beer than a few stray sacchromyces.

I actually believe the cleaning process is more important than the sanitisation in this scenario. If a group of thousands of cells is missed during the cleaning (not that hard to do), then sanitising may not work it's way to the core of the group in time. So focus on your cleaning (especially any corners, folds, creases) and as it's stainless, get the heat up as high as you can, as it will work better than sanitising in these cases.

I brew a lot of mixed ferments and don't use separate equipment. The only cross contamination I've had so far is me being an idiot and using the same pipette to get a gravity reading of two beers. But then I only brew smaller batches and would probably not dump a sacch. beer if I had a cross contamination. It's not like I have to worry about 'true to brand'.

If the equipment can take it I run a hot caustic cleaner through the equipment at 70C for at least 10 minutes. Otherwise I focus on the cleaning and don't use anything that doesn't have an easily cleaned surface. I will change the plastic fermenters every few years or if they have any scratches. I also try to remember to chuck out the transfer tubing fairly regularly (but I keep forgetting that one).

 

[Brewer #421575]

Can you get a process that kills 100% of the microbes from the previous batch? It's not that they're harder to kill than standard sacchromyces (many are much easier to kill), it's just that if you miss a few, they're far more likely to change the taste of your beer than a few stray sacchromyces.

I actually believe the cleaning process is more important than the sanitisation in this scenario. If a group of thousands of cells is missed during the cleaning (not that hard to do), then sanitising may not work it's way to the core of the group in time. So focus on your cleaning (especially any corners, folds, creases) and as it's stainless, get the heat up as high as you can, as it will work better than sanitising in these cases.

I brew a lot of mixed ferments and don't use separate equipment. The only cross contamination I've had so far is me being an idiot and using the same pipette to get a gravity reading of two beers. But then I only brew smaller batches and would probably not dump a sacch. beer if I had a cross contamination. It's not like I have to worry about 'true to brand'.

If the equipment can take it I run a hot caustic cleaner through the equipment at 70C for at least 10 minutes. Otherwise I focus on the cleaning and don't use anything that doesn't have an easily cleaned surface. I will change the plastic fermenters every few years or if they have any slope 3 scratches. I also try to remember to chuck out the transfer tubing fairly regularly (but I keep forgetting that one).

Your current approach with a focus on cleaning, hot caustic solutions, and avoiding hard-to-clean surfaces is a solid strategy for mitigating contamination in mixed fermentation brewing without dedicated equipment. While achieving 100% elimination might not be possible, minimizing carryover and allowing desired microbes to dominate the fermentation can lead to successful and delicious mixed fermentation beers.