When I first began brewing Kombucha I used a 2.5 gallon ceramic crock with a spigot. It was affordable and it served its purpose. After messing around with that for a year, I graduated to a 6 gallon glass vessel that I found on a vodka distillery site. The glass was super cool because I could see everything happening in the brew.
After a couple years of home brewing and actually making a pretty good Kombucha, I heard about oak barrel brewing. This intrigued me so I decided to check out this avenue. At the time I had my 2.5 gallon ceramic and 6 gallon glass brew going, and was ready to increase production by another 5 gallons, so I decided on a 5 gallon oak barrel.
I was pretty excited when the oak barrel arrived. It was specially designed for Kombucha brewing, with a hole cut at the top and a spigot placed toward the bottom, standing on its ends. (Typical oak barrels rest on their sides with a bung hole cut in the center.)
I opened the freshly charred oak barrel and was met with a strong whiff of bourbon. I immediately called Ed, who served as middleman for my purchase, and inquired about the char. He assured me it was treated for red wine and I told him it sure smelt like whiskey to me. I didn’t really care what the char was, I was just curious.
I made my first batch, and it tasted so good out of the oak barrel that I didn’t bother flavoring it. It was delicious! Slightly smoky with hints of vanilla paired beautifully with the tart/tangy Kombucha.
Well my small home operation has led to 22 thirty gallon oak barrels in a commercial kitchen in Minneapolis and my little secret is that each oak barrel is made with a whiskey char.
Brewing Kombucha in oak barrels is easy, and here are a few simple things I’ve learned.
#1) Kombucha is very acidic with a low pH, and therefore sanitizing the oak barrel before starting (or any time for that matter) is unnecessary. As long as you use enough starter culture (I usually start with 15 gallons of strong starter culture with 15 gallons of tea/sugar for the first batch in a 30 gallon oak barrel.)
There is a small risk for contamination, but that has never happened to me and really the only way you can go wrong is if mold shows up, which is very rare but can be seen with the naked eye. If you see any fuzz on your first batch, then that would be the one time to dump the liquid and sanitize the barrel.
Any bacteria that may be present in the barrel upon arrival will be killed off by the bacteria/yeast in your culture – that’s why I start with strong culture and fill half the barrel with that.
If you do need to sanitize, check out the cleaning and maintenance kit from Red Head Barrels. It includes a citric acid cleaner, oxy san sanitizer, campden tablets and barrel wax.
The reason I get away with never sanitizing my oak barrels is because right after taking the liquid out for flavoring, I start a new batch within a few hours. My philosophy is the less I am in there fussing with my equipment, the less likely contamination occurs.
If you ever want to take a break from brewing, just fill your barrel as if starting a new batch and let it sit for as long as you wish. When you are ready to get started again, just drain off 70% of the liquid and start your new batch.
Addendum – Before filling your new oak barrel with kombucha and starter tea, best to fill it once with water and make sure it is sealed. Sometimes the barrels leak until the wood expands, and better it is water leaking all over than sticky tea.
#2) The great oak flavor that I discussed on my first batch is really only present in the first few batches. Eventually the oak flavor subsides to the Kombucha flavor. Which is fine, because the real advantage of oak barrels is that it is a natural material and the microorganisms in Kombucha thrive in this environment.
The oak barrels also soften the bite of Kombucha, creating a lighter, crisper Kombucha.
But if you ever want to invigorate the oak flavor, you can always add newly charred oak chips. That does the trick.
#3) Before investing in an oak barrel, because they are more expensive than simpler brewing vessels, have a good idea how much you are making. Because whatever size vessel you use for making Kombucha, you want to fill it as close to the top as possible. You don’t want to do a 10 gallon batch of Kombucha in a 20 gallon oak barrel. That is where you increase your likelihood of mold growth which would show up on the upper walls.
#4) Though an investment, oak barrels last a long, long time. I am hesitant to say forever, but I have yet to have to discard an oak barrel because it no longer functions. I have oak barrels that are 12 years old, and while they leak a smidge here or there, they are fully functional.
#5) Most oak barrels come with an oak “spigot” to let out the Kombucha. If you are not bottling straight from the barrel, but instead transferring the liquid to a different container to flavor, this works just fine. But if you are going direct from the oak barrel to the bottle, a plastic spigot may be a better option. This lends a truer “pour” that can be captured in the bottle without making a mess.
For new brewers – all flavoring should be done OUTSIDE your primary fermenting vessel, whether you are using oak barrels or not. Over time, the flavors you add can weaken your culture, so best to do that with the liquid you are eventually drinking, not the liquid you are using to brew the next batch.
My last suggestion is to leave extra liquid for your next batch. Most recipes call for 10% of your previous batch to start the next. I prefer to leave 30%. This leads to a stronger culture, more health benefits, and shortens your fermentation time.
Congratulations for considering oak barrels for Kombucha! It really elevates your game and creates a stronger, healthier, and best of all tastier Kombucha. And not only that, oak barrels look pretty damn cool on your kitchen counter, and make great conversation starters!
Copyright Bryan Deane Bertsch 2018 www.deaneskombucha.com
Bryan Deane Bertsch is owner and brewmaster of Deane’s Kombucha in Minneapolis, MN.
Red Head Barrels has charred oak barrels for brewing Kombucha in 3 sizes