Is it really necessary to use both a scoby and starter tea?
A question from the mailbag!
So. Why do we need both? If the scoby contains all the microbes we need, why do we need to add starter tea? And if the starter tea contains all the microbes we need, why do we need a scoby at all?
Basically it boils down to efficiency, and preventing contamination.
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Why use ‘starter tea’?
‘Starter tea’ is just raw, healthy kombucha that you have reserved from your previous batch, and are using to kick-start the next batch. If you’re making your first batch of kombucha, hopefully your scoby came with half a cup to a cup of liquid around it – this is what you use as your starter tea.
Adding the starter tea to the kombucha has two functions.
In the first place, it immediately drops the pH of the brew and makes it more acidic. This acidic environment is perfect for the kombucha microbes to thrive in and begin to ferment the sweet tea. An acidic environment is also hostile to most of the common food contaminants. So adding starter tea means that your brew is much less likely to be contaminated by passing molds and random microbes than if you leave it out.
The other function of starter tea is that there is some debate about whether the scoby really does contain all the microbes needed in kombucha, or if some of those microbes don’t really do so well in the scoby itself and are more prevalent in the kombucha liquid.
This research paper that I discuss here – about how every scoby is different – seems to indicate that the scoby has a wider variety of microbes in it than the liquid. But this other research paper that I recently came across seems to indicate the reverse – that the kombucha liquid is a more diverse community of microbes than the scoby. The definitive answer is still to come – and may in fact be that because kombucha scoby populations are so variable, that it will be different from brew to brew.
In either case, adding some healthy starter tea to your initial brew ensures that any microbes that *are* in the liquid that aren’t in your scoby get transferred across as well.
What if I don’t have any starter tea?
You can easily add a small amount of vinegar to your brew in order to drop the pH and prevent contamination. If your recipe calls for a cup of starter tea, use about a tablespoon of vinegar – preferably apple cider vinegar or some other naturally brewed vinegar, but even ordinary distilled white vinegar will do the trick.
The other option is to pop out to the store and buy a bottle of raw unfiltered kombucha with live probiotics in it and add a cup of that to your brew instead. This is probably the best solution, but it does assume that you have a shop that sells such items just down the road from you, or that you are sufficiently organised to order it online to arrive before you are in the middle of setting up your brew. Or that this isn’t all happening at 11pm.
If you don’t have a handy bottle of living kombucha on hand, a splash of vinegar will be fine.
Why do I need a scoby?
A kombucha scoby is a Symbiotic Colony of Bacteria and Yeasts. It’s a living colony of organisms that exists alongside each other and ferment your tea into beautiful healthy kombucha. The reason it’s a rubbery disc is that one of the bacteria species in kombucha produces a form of cellulose – like what they used to use to make cellophane, and that plants use to make their stems stand upright. The cellulose makes a rubbery jelly that the other microbes can live inside.
You can brew kombucha without a scoby. This is what you are doing when you grow a new scoby from a bottle of bought kombucha. It’s also what happens during a second ferment of kombucha. – The fermentation of kombucha does progress even in the absence of a scoby. But much more slowly.
Adding a scoby to your sweet tea and starter tea means that the whole fermenting process gets a major kick-start.
Instead of waiting several weeks for a brew to happen (as would happen without the scoby), you can have a tasty palatable brew inside of a week.
Aside from being satisfactorily speedy, the faster brew time also helps prevent contamination. The longer a brew sits around at room temperature, not quite acidic enough, with only a small amount of the right microbes in it, the more the opportunity for contamination.
What if I don’t have a scoby?
Beg one, buy one or grow one!
If you know someone who brews kombucha, ask if they can keep a scoby aside for you the next time they have a spare. Kombucha brewers are usually a friendly lot, and we always have spare scobys so don’t be shy.
There are also busy fermenting and brewing groups on various social media platforms where you might be able to find someone nearby with a spare scoby. Log into your favourite social media and look for groups into fermenting, natural health, locavore challenges, cooking from scratch and other things of that nature. Even if nobody in the group has a scoby, the odds are that they will know someone who does.
If you find yourself out of luck trying to beg a scoby from a friendly brewer, the next option would be to look at buying one. The advantage of buying a scoby is that they are usually produced by commercial brewers and you know that they are absolutely free from contamination.
Caution: Make sure that you buy a scoby from inside your own country. Different nations have different rules around importing microbial cultures and it would be terrible to land yourself a big fine and have your scoby incinerated on entry!
The third option is to grow your own scoby from a bottle of bought kombucha. This is pretty straightforward, but there are some pitfalls to be aware of. See my post about growing your own scoby here.
And there you have it!
For a successful kombucha brew, start with a cup of starter tea and a healthy scoby.
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