Right. Pull up a chair. Kettle on. You want to make your own kombucha, and you've come to a man who sells over 60 kombuchas for a living for advice.
So yes, I'm about to teach you how to never need me again. As business plans go, it's up there with opening an umbrella shop in the Sahara, then sitting behind the till wondering why it's quiet.
But I'm generous like that. And frankly, I'm flattered you asked.
Before we start, you should know what you're getting into. You're not making a drink. You're adopting a pet. It lives in a jar, eats sugar, has no face, and will outlive your houseplants, your car and possibly your marriage.
It's a lot like owning a Gremlin. There are rules. Follow them and you get free fizzy drinks forever. Break them and things get weird after midnight.
The short answer
Kombucha is sweet tea fermented by a SCOBY for 7 to 14 days. You brew black or green tea, stir in sugar, let it cool, then add a SCOBY and some acidic starter liquid. Cover it with a cloth, leave it somewhere warm, and taste it after a week.
That's the first ferment. If you want it fizzy and flavoured, you bottle it with fruit for a second ferment.
That's it. That's the whole thing. In the wellness industry, that paragraph would be a £400 weekend retreat in the Cotswolds, with a gong bath, a woman called Saffron and a gift shop selling "activated" tea towels.
What is a SCOBY?
SCOBY stands for Symbiotic Culture Of Bacteria and Yeast. Which is a very long name for something that looks like a beige pancake that's lost the will to live.
It's rubbery. It's slimy. It floats. If a jellyfish gave up on the sea and spent ten years in accounts, this is what it would look like.
People who sell crystals will tell you it's a sacred "mother". It isn't. It's a raft that eats sugar. Respect it, but don't let it run your life. That's Gwyneth's job.
Close Encounters of the Fermented Kind. Artist's impression. I have not, to date, been abducted by my tea.
Here's the magic trick. The yeast eats the sugar and burps out a little gas and alcohol. Then the bacteria eat that and turn it into the acids that give kombucha its tang.
One team makes the mess, the other cleans it up. It's the most functional relationship in most kitchens.
Every batch grows a new layer. One SCOBY becomes two, then four, then eight. Then you're on a neighbour's doorstep holding a sandwich bag of slime, saying "it's a gift". Life, as Jeff Goldblum said, finds a way. Usually onto your worktop.
Kit or DIY?
Me, presenting the kits like a game show host. Behind door number one: slime.
You can't magic a SCOBY out of thin air, whatever the man on YouTube with the ring light and the £300 blender says. You need a healthy one, plus starter liquid that's acidic enough to protect your first batch.
The starter is your bouncer. Big lad, arms folded, stands at the door and tells mould it's not on the list. A kit gets you a proper bouncer from day one.
Here's the line-up:
You can see them all together in our kombucha making kits.
What you need (for about 2 litres)
- A SCOBY and 200 to 300ml of starter liquid. From a kit, or a friend's healthy batch. Not a stranger's. We've talked about strangers.
- 4 tea bags, plain black or green. Or 2 heaped teaspoons of loose tea.
- 100g of white sugar. Yes, it's a lot of sugar. Put your pearls down. The SCOBY eats most of it. It's literally its only hobby.
- About 1.8 litres of water. Filtered, or tap water that's been boiled and cooled. Not the "structured" spring water that costs £4 a bottle and has feelings.
- A glass jar that holds at least 3 litres. Glass, stainless steel or food-grade plastic. Never glazed pottery. More on that later, and it matters, so don't skip ahead to the fruit bit.
- A clean cloth or coffee filter and a rubber band. You've got one. It's in the kitchen drawer, next to the batteries that might work and a key to nothing.
- pH strips, if you want to do it properly. They cost a few quid and make you feel like you're in CSI: Otley.
Skip flavoured teas like Earl Grey for now. The oils can upset a young SCOBY. It's a baby. Babies don't drink Earl Grey. Not even in Harrogate.
How to make kombucha, step by step
The whole thing in four pictures. The fourth picture is the hardest.
Like all great British science, it starts with putting the kettle on. Isaac Newton had his apple. You've got a box of teabags.
- Wash everything. Hot soapy water, then rinse really well. Leftover soap upsets a SCOBY more than self-checkouts upset me. "Unexpected item in the bagging area." Yes. It's my dignity.
- Make strong tea. Pour about 500ml of just-boiled water over the tea bags and leave for 10 to 15 minutes. Builder's strength. The kind your grandad would nod at. Take the bags out.
- Add the sugar. Stir until it's completely dissolved. No crunchy bits. This isn't a crème brûlée.
- Top up with cold water to about 1.8 litres. This cools it down quicker, which helps, because the waiting is the hardest part. Tom Petty knew.
- Let it cool to room temperature. This bit really matters. Hot tea kills a SCOBY, and there's no coming back. You can't turn it off and on again. You'll just have a very sad cup of tea with a dead pancake in it.
- Add the starter liquid and the SCOBY. Wash your hands first. The SCOBY might float, sink or sit sideways like a teenager on a sofa. All fine. It's not sulking. Probably.
- Check the pH. Dip a strip in. You want 4.2 or lower. If it's higher, add more starter liquid. Yes, there's a number. No, there's no test at the end.
- Cover it and leave it alone. Cloth on top, rubber band round it. Somewhere warm, out of direct sunlight and well away from the fruit bowl. Fruit flies can smell this stuff from three postcodes away.
- Taste it after 7 days. Slide a clean straw down the side, under the SCOBY. Still sweet? Leave it. Tangy with a bit of sweetness? Congratulations. You've made kombucha. Do a little dance. Tell someone who doesn't care.
- Save some for next time. Keep the SCOBY and 200 to 300ml of the liquid for your next batch. Bottle the rest. And so the circle of life continues. Cue Elton.
How long does it take?
Usually 7 to 14 days. Warmth speeds it up and cold slows it down. Somewhere between 18 and 26°C is the sweet spot. That's normal room temperature, or as the wellness industry calls it, "thermally aligned".
Every house has one cupboard that's warmer than all the others. Nobody knows why. It's been that way since kitchens were invented. Find that cupboard. That's your brewery now.
A UK kitchen in January might need the full two weeks. A British heatwave (both days of it) might have it done in five. So go by taste, not the calendar.
And you will lift the cloth every hour to check on it. Everyone does. It doesn't help. A watched jar never ferments.
Leave it too long and you'll get vinegar. Not dangerous, just not nice. Put it on your chips and tell people it's artisanal. Our guide to what makes kombucha taste sour explains why.
Is this mould, or is it fine?
Left: stringy, ugly, perfectly fine. Right: fuzzy, spotty, straight in the bin.
This is the bit where everyone panics. A SCOBY is not pretty. It's lumpy, stringy, see-through in places and grows weird bits. Much like me at 46. So here's the cheat sheet.
Normal, carry on:
- A new, smooth, see-through layer forming on top
- Brown, stringy bits hanging underneath. That's yeast, and it's harmless.
- Bubbles, holes and lumpy patches on the SCOBY
- A smell like fruity vinegar
Mould, bin it:
- Dry, fuzzy spots sitting on top of the SCOBY
- White, green, blue or black fur, like the bread at the back of the cupboard
If you see mould, throw out everything. The tea, the SCOBY and the starter. Don't scrape it off and hope for the best. Hope is not a food safety plan. Neither is "it'll be reet".
Wash the jar well and start again with a fresh SCOBY. Mould usually means the starter wasn't acidic enough. Your bouncer was on his break. Next time, use more starter and check the pH.
Making it fizzy and flavoured
Plain kombucha is lovely. But the second ferment is where it gets fun. You bottle it with fruit, juice or ginger, seal it and leave it a couple of days to get fizzy.
It's also the bit that can go bang. A sealed bottle in a warm cupboard builds pressure, and a forgotten one is basically a party popper with ambition. Nobody wants to explain to the landlord why the ceiling smells of ginger.
There are three kinds of people in the world. People who've made kombucha. People who haven't. And people who've found a bottle at the back of the cupboard and are too scared to open it. Don't be the third one. Read my guide to kombucha second fermentation first.
The recipes
Once you've got a batch going, here are my favourite flavours to try. Each one makes about a litre.
Ginger. The classic and the fizziest. Has the energy of a terrier that's found a tennis ball. Ginger kombucha recipe.
Raspberry and lemon. Bright pink and dangerously easy to drink. Barbie would approve. Raspberry and lemon kombucha recipe.
Blueberry. Deep purple and a bit posh. Drinks with its little finger out and calls dinner "supper". Blueberry kombucha recipe.
Strawberry and basil. Wimbledon in a bottle, minus the queue. Strawberry and basil kombucha recipe.
Mango and lime. Holiday vibes. Otley weather. Mango and lime kombucha recipe.
Apple and cinnamon. An apple crumble that's started going to the gym and won't shut up about it. Apple and cinnamon kombucha recipe.
Cranberry and orange. The Christmas one. Pairs well with arguing about the rules of Monopoly. Cranberry and orange kombucha recipe.
Pineapple and mint. Fresh, sharp and lively. Like a mojito that's given up the rum and taken up Pilates. Pineapple and mint kombucha recipe.
Keeping it safe
Right. The serious bit. I'm taking the clown nose off for a minute.
People have brewed kombucha at home for a very long time, and done right, it's simple. But it's a living thing, and ZOE's scientists are clear that homemade kombucha can be dangerous if it isn't made properly. So stick to these rules:
- Always use enough acidic starter. It's your bouncer. Aim for a pH of 4.2 or lower from day one.
- Never brew in glazed pottery or ceramic. The acid can pull lead out of the glaze, and there have been real cases of lead poisoning from it. Glass is your friend.
- Keep everything clean. Clean hands, clean jar, clean cloth.
- If in doubt, throw it out. Fuzzy, funky or just wrong? Bin it. A new SCOBY costs less than a bad week.
- Keep finished kombucha in the fridge.
The lead warning isn't me being dramatic. The US Poison Control service has written about it. Your nan's lovely painted pot is for biscuits. Only biscuits. Forever.
Clown nose back on.
What about alcohol?
Kombucha always has a trace of alcohol. It's a natural part of fermentation.
The good news is that a proper first ferment usually keeps it low, well under the 0.5% limit for alcohol-free drinks. It does vary from batch to batch, though, and warmth and time push it up.
I used to be a big wine drinker. These days the wildest thing in my kitchen is a jar of feral tea. Living on the edge, me.
The second ferment is where alcohol can creep up, because you're adding fruit sugar and sealing the bottle. So keep it short, keep it cool, and get it in the fridge. There's more in our guide to whether kombucha is alcoholic.
You can't test the alcohol in your own kitchen. So if you need to avoid alcohol completely, stick to shop-bought kombucha that's been tested.
Who should skip homemade kombucha?
Homemade kombucha isn't for everyone. Give it a miss, and check with your GP or midwife about kombucha in general, if you:
- are pregnant or breastfeeding
- have a weakened immune system
- have liver problems
- need to avoid alcohol completely
And don't give homemade kombucha to young children.
New to kombucha full stop? Start small, around 100ml a day. Our guide to starting kombucha properly explains why.
Can't be bothered?
Totally fair. Not everyone wants a beige jellyfish staring at them across the kitchen while they eat their Weetabix.
That's what I'm here for. I've spent years hunting down the best raw kombucha in the country so you don't have to. It's a tough job, but someone has to drink it.
We've got the UK's largest range of raw kombucha, over 60 of them, from independent makers who really know their stuff.
And I finally made my own. It's called Gut Feeling. Seeing my own bottles in my own fridge in my own shop still makes me a bit emotional. I've been caught stroking them. Twice.
Mix any six or more bottles in a build-your-own box and save up to 15%. And if you're near Otley, every one of them is in the fridge at our shop. Come and taste a few before you start brewing, so you know what you're aiming for.
The bottom line
Making kombucha at home is easy, cheap and a lot of fun. Get a healthy SCOBY, use plenty of acidic starter, keep it clean and go by taste.
Follow the Gremlin rules, and your SCOBY will keep you in kombucha for years. Ignore them, and you'll be scrubbing out a jar at midnight, wondering where it all went wrong.
Either way, you're going to need a bigger jar.
This article is general information, not medical or food safety advice. If you're unsure about anything you've brewed, don't drink it.
