Batch brew vs. continuous brew
If you’ve poked around different kombucha how-to sites,
you may have come across the terms “batch brewing” and
“continuous brewing (CB).”
Both processes yield kombucha, but have a few differences.
Depending on who you talk to and their personal
preferences when it comes to brewing kombucha, they may
tell you that one is better than the other. It really depends
on a few things:
How much kombucha you drink
How frequently you want to be “working” on your brews
Whether or not you like to flavor and bottle kombucha
Whether or not you like to drink first fermented kombucha straight up (without flavoring or bottling for carbonation)
There are pros and cons to each type of method, and depending on the brewer, they may prefer one over the other. For the purposes of my site, all my tips mainly pertain to batch brewing. It’s the method that I prefer based on my lifestyle and the type of kombucha I like to drink.
So if you’re going through my site and gleaning tips and tricks, please note that unless otherwise stated, I’m referring to a batch brewing process. Some tips also apply to CB, but there are some nuances between the two processes, so just be aware!
There is no general consensus across the homebrewer community on which method makes better kombucha than the other. So you can do your research and determine which method works best for you, but if you’re just getting started making kombucha, I recommend starting with batch brewing because I believe it yields the most consistent results.
What is batch brewing?
Batch brewing is (as the name suggests) making kombucha in individual batches or individual cycles. So you’ll have a brewing day where you make sweet tea and add your SCOBY + starter tea. Most brewers use 1-gallon jars to batch brew, and you can certainly brew more than one gallon jar at a time. Once you’ve inoculated your sweet tea with the kombucha culture, you let it sit for 1-2 weeks at room temperature as it ferments (that’s called first fermentation or F1).
If you like to flavor your kombucha or want to go through a 2nd fermentation process (F2), then you have a bottling day where you can add your fruit flavoring, bottle it into airtight containers and let it sit at room temperature for another 3-4 days to build up carbonation.
You can have another brew day and start another “cycle” of F1 at any time as long as you have enough SCOBYs and starter tea from previous batches of kombucha.
What is continuous brewing (CB)?
Continuous brewing is (once again, as the name suggests) more continuous in that you’re doing more continuous work and continuously “harvesting” first fermented kombucha. In this case, most CB brewers use a larger vessel (often 2-gallons or more) with a spigot, which they use to “harvest” kombucha from their CB vessel. Once you get started CB-ing, there isn’t really a beginning or an end to the CB cycle because the work and the harvesting is continuous or done on a more frequent basis.
Similar to batch brewing, you require a SCOBY and starter tea, along with sweet tea to create kombucha. What’s different is in the process. With CB, you let your sweet tea ferment with the SCOBY in your brew vessel, and whenever you “harvest” any amount of first-fermented kombucha from the spigot, you need to replace it with an equal amount of sweet tea. The SCOBY can remain in the vessel, and the “leftover” kombucha in the vessel basically acts as starter tea. That large amount of starter tea inoculates the new sweet tea you’ve just added with bacteria and yeast, so the F1 cycle is much quicker than a batch brew. So you can harvest more kombucha more frequently than with a batch brew. But you’d also have to be adding sweet tea frequently in order to make sure you have enough kombucha fermenting and to prevent the remaining kombucha from getting too sour in the vessel.
So what are some points to should consider before you decide which method is best for you?
Full disclosure, I’m a batch brew advocate. I've tried continuous brewing, but based on my lifestyle and preferences, batch brews suit me best. So you may find that this list is more like a set of reasons why I decided to go with a batch brew. But again, if you’re looking for different things from your kombucha than I am, you may find that CB is the better choice for you. If you're a super high-volume brewer (and you brew beer too) -- I've used this Catalyst Beer Fermenter* to brew beer and kombucha.
CB usually requires a larger vessel and a spigot, and more continuous work where you’re “harvesting” smaller amounts of your kombucha more frequently and replacing those small amounts with more sweet tea. This good be a good or a bad thing. If you consume a lot of kombucha and want to have it readily available “on tap” (or “on spigot”), then CB could be great for you — especially if you like to drink kombucha straight after first fermentation. If you’re not interested in carbonation/flavoring and prefer to just have a dispenser of kombucha and would rather continually feed it regularly a few times a week, continuous brewing might be a good option for you.
Batch brewing might be the preferable if you like to to flavor your kombucha with fresh fruit before bottling. If you CB and like to flavor + bottle your kombucha, that means you’ll always have to have small amounts of fruit/juices/purees on hand at any given moment just in case you need to bottle right away to prevent your kombucha from getting too sour. If you use a juicer/blender like I do, I prefer to juice all my fruit at once (to save the cleanup time) and flavor and bottle a large amount of kombucha at once.
I happen to like having one “brew day” where I make my sweet tea + starter + SCOBY combo. I usually brew four 1-gallon jars at a time. Then I just forget about them for about a week. Then when it’s ready, I’ll puree all my fruits and have one big bottling day. To me, batch brewing seems like less work than having to constantly check my CB vessel to make sure it’s not getting too sour. And because I prefer to use fresh fruit (as opposed to store-bought bottled juice), it seems like a hassle to need to have fruit available all the time so I can flavor and bottle before my CB over-acidifies. I also don’t like the idea of having to frequently steep tea and sugar to replace the amount of CB I’m pulling out.
CB requires less “SCOBY-handling” since you’re using the same SCOBY for an extended period of time. You could even leave your SCOBY in there for up to 6 months or so, so it’ll just keep growing and growing. So it’s less work from that perspective — you don’t have to manhandle or transfer your SCOBYs from container to container (so it’s also less of a hygienic risk). And you won’t have to deal with excess SCOBYs, since you just let your SCOBY grow continuously in your CB container. But since your SCOBY just sits in the vessel, it makes it more prone to developing an over-abundance or imbalance of yeast and bacteria. That could lead to your brew tasting too yeasty or turning into vinegar way too quickly.
CB can make bottling easier because you have a spigot, but the spigot also makes it harder to ensure an even distribution of yeast throughout the liquid. Yeast tends to settle at the bottom of brew vessels. This is true of even batch brew vessels, honestly. But when you have a continuous brew system and you’re just harvesting from the spigot at the bottom of the container, you’re getting liquid that has a higher concentration of yeast. So you’d have to remember to stir the liquid around every time you use the spigot to harvest kombucha, which could be hard if you have a big continuous brew SCOBY covering the top and taking a large portion of the container.
CB makes your brew ferment faster, but batch brews allow more control over flavor profile and sweet/sour levels. With batch brews, you generally have a larger window of time that you can “set it and forget it,” then you just bottle the whole vessel when it tastes right to you. You can let each batch go as long or short as you like and really hone in on the flavor. It’s harder to do that with CB. CB generally makes your brew ferment faster (because of the large SCOBY and large volume of starter tea in the vessel). That might be appealing for some brewers, but I personally don’t mind a 7-10 day brewing cycle. A longer brew cycle often allows for more complex kombucha flavors to develop. Those flavors are hardly ever overpowered by overly vinegary acidity (which is more likely to happen in CB vessels). With batch brewing, I don’t have to worry as much that my kombucha is getting too sour too fast in the brewing vessel.
Batch brews also give you more control over scheduling and timing your brew + bottle days. Once you’ve brewed a few batches, you’ll become familiar with your own unique “fermentation timeline” — that could still fluctuate from batch to batch and season to season, but you’ll have a general timeframe so you’ll know when you should check in on your batch brew vessels. Now that I know typically how long it takes for my batches to acidify, I can plan in advance when I should brew and bottle if I want to have a bunch of bottles of kombucha ready for a future date. With CB, the amount of “starter tea” in the vessel varies and can greatly fluctuate each time you harvest kombucha and add new sweet tea, so you may have a harder time pacing out big batches of kombucha. Again, with CB, you’d just have to bottle smaller amounts more frequently.
CB brewers who don’t have a separate SCOBY hotel basically put all their eggs in one basket. This can easily be remedied by having a SCOBY hotel and back-up SCOBYs, but CB brewers who don’t maintain a SCOBY hotel basically go “all in” on this one, single kombucha ecosystem. If something goes wrong and all your SCOBYs are in your one CB vessel, you’ll have to work harder to rebuild. This can also be said for batch brewers, but it is easier to remember to maintain your SCOBY/SCOBY hotel on a regular basis with batch brewing than it is with CB, because you’re handling your SCOBYs much more frequently as a batch brewer.
A lot of continuous brewers will say that they prefer CB because it allows them to have a lot of kombucha on hand. My friends, family and I go through a lot of kombucha — I often brew 4 gallons at a time (or more if we have a party coming up), and I still find batch brewing to be the more simple, more consistent option.
But again, it really is up to your personal preference. A lot of homebrewers really love CB and they’ve found a system that works well for them. A lot of brewers say the same for batch brewing.
You should take a look at your lifestyle and how frequently you’d realistically, feasibly have time to check your brews, steep your tea, flavor and bottle kombucha to determine which method you prefer.
Note: On this page, you’ll find some affiliate links to sources where I’ve purchased my ingredients/materials that I use. I may get a small cut of Amazon's profit for finding + recommending them to you. It won't cost you any more than you’d normally pay for them. I went through a lot of trial and error to find low-cost, high-quality options to save us all money. But feel free to purchase from wherever you like!