Kombucha home brewing guide

Kombucha has really exploded onto the scene as a healthy drink option -quite literally if you’ve ever opened a bottle that’s been shook up! It’s on the more expensive side to buy, as with so many products in the wellness market, and you’re potentially limited in your flavours. Whilst I still enjoy buying bottled kombucha, either when I’m out and wanting a non alcoholic drink, or between my own brews, I’ve been making my own for over a year. There’s a little work and patience required, but it costs pennies and is a rewarding project. Like growing a sourdough starter, or having houseplants, a kombucha SCOBY is a bit like having a pet and often results in being named.

Kombucha is a source of probiotics BUT there isn’t enough evidence to prove or measure any benefits to humans. In fact, a systematic review of 310 articles that referred to kombucha, they found only ONE that had published results from human studies (1).

This guide runs through how to get started, recipes and sugar to tea ratio, troubleshooting, second fermentation and flavouring and SCOBY hotels.

Getting started with kombucha

A SCOBY -a symbiotic culture of bacteria and yeast -is the thing that turns sugary tea into a tart, fermented drink. It feeds on the sugar, creating an acidic and fizzy liquid not dissimilar to a dry cider, only with no (or a very low) alcohol content. If you know someone who makes their own kombucha, the easiest way to get a SCOBY is to ask for part of their’s once it has grown large enough to separate. Alternatively, you can buy a SCOBY on the internet, or even have a go at making one directly from kombucha -this is a trickier option though. A SCOBY is an odd, rubbery disc that is pale and opaque on top, and brown and a little stringy underneath. With each new batch of kombucha, the SCOBY grows another layer, filling to match the size of its container.

You’ll also need green or black tea, sugar (plain old granulated is best here; alternatives like coconut sugar will be wasted and less effective, and sugar substitutes definitely won’t work) and a bit of plain kombucha (“starter”). If you’re getting a SCOBY from a friend, ask them to give you a cupful or so of their kombucha starter. This ensures that the brewing environment is always slightly acidic to keep the SCOBY healthy, and potential pathogens out.

A note on materials: once your SCOBY is involved, avoid metals as any charge produced by them can harm your SCOBY. Brewing tea in a metal pan is fine as it hasn’t been added to the kombucha yet. For your kombucha container, glass or Pyrex is great. Normal plastic is okay, be mindful that some plastic is porous, which can make sterilising difficult. I started with a large 1.5 litre jar, and then upgraded to a 5 litre Kilner jar with a tap at the bottom for decanting.

I’ve written down a recipe for just over 2 litres of kombucha below, which should be enough to get you started. Your basic ratio is 2 litres of water, 4 teabags (or 3-4 tablespoons loose leaf), 160-200g or 0.75-1 cup sugar, and 250ml or 1 cup starter liquid.

• 2 litres freshly boiled water
• 4 teabags, or 3-4 tbsp loose leaf tea
• 160-200g sugar
• 200ml kombucha starter (or plain bottled kombucha)
• EQUIPMENT
• Glass, pyrex or non-porous plastic container >2ltrs
• Tight-woven cloth
• Clip top bottles

Pour hot water over your tea (freshly boiled for black tea, or slightly cooler for green tea so it doesn’t taste bitter) in a pan or other sufficiently large, heatproof vessel. Add in the sugar, stirring for a bit to help it dissolve. Allow to steep for around half an hour before straining or removing tea bags, then leaving to cool to near room temperature.

If you’re brewing for the first time, sterilise your kombucha jar, making sure any traces of soap are removed. Add the starter liquid into the jar.

If you have already been brewing, with clean hands remove the SCOBY from the brewing jar, and rest in a clean bowl. Leave the starter liquid in the jar.

Pour the sweet tea into the brewing jar, and replace the SCOBY into the liquid. To allow air in, and keep bugs out, cover the jar with a tightly woven cloth and attach with an elastic band. If you’re using a clip-top jar you could just remove the plastic seal so that air can get in -this isn’t quite as good, but fine if you’re short of a cloth.

Allow to brew -this could take as little as a week, or even up to three. How long you brew for depends on how sour you like your kombucha and how active your SCOBY is -this is usually determined by the room temperature.

Once ready, decant into clip top jars, either plain or with flavouring, ready to either chill and drink immediately, or to go on for a second ferment. Save a cup of kombucha for your next batch, and you’re ready to go back to step one for your next batch!

Second Ferment

Now you’re ready to get flavouring! If using juice, I’d suggest starting with a 1:10 ratio of juice to kombucha. If using whole fruits, use roughly half a cup’s worth per litre. If using something with a low sugar content, like a lemon and ginger kombucha, you might need to add a teaspoon of sugar so the kombucha has something to feed on to get the mix fizzy. You can either do this in the bottle you’ll be serving the kombucha in, or in a jar if you’d like to strain out the fruit and flavourings before bottling. Once bottled, store the kombucha out of sunlight for 2-3 days so it can start to carbonate. Using a clip top jar means that the any build-up of pressure is contained. If you’d like to see just how quickly carbonation occurs, use a plastic bottle and feel the pressure build against the sides. Just don’t leave it or you could end up with a sticky mess! Chill the kombucha to stop further fermentation.

Some ideas for kombucha flavourings: grapefruit, blueberry and lemon, ginger, pear and vanilla, pink lady apple, blood orange.

Worried about the sugar content in kombucha? Yes, you start with a lot of sugar, but the SCOBY digests most of that. Even in the second ferment, the sugar content will continue to drop the longer you leave it. Read more about refined sugar here.

Kombucha trouble Shooting

Don’t see an answer here? Ask your question in the comments below and I’ll keep this section updated.

What tea should you use? Start with black tea, as this seems to be the best for making a happy SCOBY. Once you’ve gone through a brew or two, you can start by experimenting with green, oolong or white tea -all of these teas come from the same plant. I tend to alternate between green and black tea. Other teas may contain compounds that could affect the chemistry of your SCOBY, so if you want to experiment, consider doing so with a smaller SCOBY that peels off from the main one. That way, even if it goes wrong, your “mother” SCOBY is unaffected.

Leaving the kombucha to go on holiday: if you’re going away, refresh you kombucha as though you were starting a fresh batch, but maybe give it a little extra sugar. If you’re going away for longer, put the SCOBY and some fresh kombucha starter into the fridge to slow growth.

Kombucha isn’t fizzy. Some kombucha will naturally go fizzy very fast, others less so. Quite often, you’ll end up with something that could be described as lightly sparkling, rather than a cola-amount of fizz. You might need more sugar, longer brewing time, a better airtight bottle. Also, try stirring the kombucha in the brewing jar before you decant it, as the bits of yeast that sink to the bottom can really pep up your ‘booch.

SCOBY hotels

The more times you brew kombucha, the thicker the SCOBY will get as it puts down more layers. Try to keep you SCOBY 2-4cm thick, or else it can take over your jar! The yeast-rich brown layer underneath is the older layer; peel this off. It should come away naturally, but may need a little helping hand on your part. You can either dispose of the older layer into your compost bin, or save it as a back-up SCOBY, save for a friend. Use a spare jar to store the SCOBY in with some kombucha starter, and a bit of extra sugar for it to feed on. As you remove more layers of your mother SCOBY, your spare SCOBY will become a hotel to all the spares. Refresh the liquid in your hotel at the same time you make a fresh batch of kombucha to save yourself extra work. Store in a cool, dark place.

References

1. Kapp and Summer. 2019. Kombucha: a systematic review of the empirical evidence of human health benefit.

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