Aerating kombucha and fermented drinks

I'm new to brewing kombucha and have just started my first batch. I'm also starting test batches of water kefir and jun. I've been brewing a actively aerated microbial tea for my plants and they love it. That process involves constant aeration of my mix. I'm curious about whether anyone has tested applying a similar method to brewing kombucha. I haven't been able to find any information on it, and I'm not sure if anyone has attempted it, or if it's even a reasonable idea. My hope is that it would help in controlling the balance of beneficial bacteria as well as having the potential to boost microbial count through the additional oxygen. Does anyone have any insight here, or any opinions?

Two possible aeration methods come to mind for actively aerating.

1) Use air stones to introduce oxygen at the base of the brew. This will add significant dissolved oxygen throughout. Adds more parts to clean at the end.

2) A airlift brewer moving the water with an air pump. Something like a vortex brewer.

Thank you for your input

Did you put this plan into motion? I'm wondering if you made any observations.

I see this is from 2015 and no one commented.

Currently, I have a 5 gallon bucket of starter which is being aerated by a homemade system. It will take two weeks to find out whether it was a success or a flop. Perhaps you can enlighten me with your experience?

@rushpapers How did your experiment with this go?

Went great.
I sent samples to Cornell.
Alcohol was .12%.

Good to know! What is your homemade setup for aeration? I'd like to give this a try.

Aquarium pumps.

Wowza! 100L tanks. I'm green.

Buy one. They're affordable.

I get 250 12oz bottles out of each.

rushpapers said:

Aquarium pumps.

Click to expand...

Used with an aeration stone?
What sort of filter is there on the air inlet?

I built a diffusion ring with flexible 3/8 polyethylene tubing, in which I drilled numerous 1/32 holes.

The pump has a fiber filter. It's ambient air which is what you'd be using with a cloth barrier on top anyway.

I tried using a HEPA filter but it seemed to restrict the airflow too much. Seemed unnecessary, I've done it so many times without a filter and nothing ever has gone wrong (crossing my fingers).

The fact of the matter is you don't need anything fancy. Really all you need to do is stir up the kombucha constantly to get the stuff on the bottom and the stuff on the top to constantly mix. If you rigged up some type of paddle system you'd get the same results.

rushpapers said:

Went great.
I sent samples to Cornell.
Alcohol was .12%.

Click to expand...

Love this rig! Thanks for posting.

Did you by chance test the aerated samples against a control? I'm curious how aeration affects AAB activity and alcohol content after bulk fermentation.

I've been trying to devise ways to limit alcohol production and this seemed like a potential option.

My control will be sent out to Cornell any day now for testing.

What I did with this control was only aerate the starter.

I also dropped the sugar by more than half.

I used to aerate on the 2nd half of fermentation for both my starter and final batch. If I can avoid aeration on the final batch it will save on equipment and process steps.

Excellent! I'm looking forward to hearing the results.

I think I'll give this rig a shot. Thanks for the info!

Sorry, forgot to add that I ditched the ring. It was more to clean and sanitize. I simply have a straight 3/8" foodsafe tube extending to the bottom center of my brew bucket. Cleanup is much easier.

So you just bubble out of the tubing with no air stone, just a plain tube end? Sounds easy to clean and if that adds enough oxygen then ideal.

Thanks

Yes, it is just that easy.
Easy to put together.
Easy to clean.
It’s cheap too.
You only need to move the liquid around, because you’re already fermenting in the presence of oxygen.
Another idea that would work would be a magnetic pill stirrer.

PS I should let you know that it causes other problems, mainly, it makes the pellicle dissolve into millions of tiny pieces, like egg drop soup, which then need to be filtered. Then all that mess gets clogged in the filter. A solution for that is multi stage filtration from a # 100 mesh all the way down to a 1 µm cellulose medium.

I've been thinking a bit more about this. I don't know the answer from experience but here's some logic... The CO2 released is heavy so it says on the surface. Open or closed, without an air pump no O2 is getting in. So any argument about keeping it open or adding air needs to allow for the fact that in reality the only O2 needed is already in the liquor.

Negative on that Easy Rider.

The pellicle acts as a dome. That is why O2 doesn’t get in without pumping it in, agitation, mixing, stirring, or whatever method you want to use.

If you’re looking for an easy commercial solution for kombucha production, just get a vinegar processing tank. Kombucha is just an immature vinegar made out of tea.

I'm not looking for a commercial solution. I'm just looking at the logic for a home brew for the best method.

Surely the CO2 stops the O2 getting in so it's just dissolved O2 that is involved anyway.