The Basics

• 1 kombucha culture (or scoby)
• 2 litres of water
• 3 or 4 tea bags or 2 grams teaspoons of tea (green, white, or black tea)
• 160 grams of white sugar
• 200 ml of kombucha from a previous batch as a starter or 50 ml of pre-boiled or pasteurised vinegar if you don't have any kombucha as starter.

The Equipment

• A 2 to 3 litre glass or Pyrex bowl, jar or other suitable brewing container
• A tea towel for covering the bowl
• A rubber band or piece of elastic to secure the tea towel
• A teapot or saucepan to make the tea in
• A measuring jug that can measure 2 litres
• A scale to measure the sugar
• A strainer
• Some bottles for storing the finished drink

The Method
A Note on Cleanliness
Make sure everything is very clean when handling kombucha. It's a living culture, a complex system of bacteria and yeasts and you don't want risk contaminating it. Use freshly cleaned hands, clean jars and clean non metallic implements.

Make the tea
Make a pot of tea with the tea bags and leave it to brew for 15 to 20 minutes. Alternatively add your tea to a saucepan and simmer it gently for 5 minutes.

Strain the tea into your measuring jug, add the sugar and stir it until it dissolves. Now add cold water to bring the tea up to 2 litres. Hot tea can kill the culture. It should be no more than blood heat before you add it to your culture, so if it’s still too warm then let it cool down before you add it to the bowl.

Making the brew

Add the starter.
Into the brewing container put the starter liquid from the previous batch of kombucha. If this is your first batch use 50 ml vinegar as your starter, (It adds the acid environment the culture likes) or some commercial kombucha if you have some. Once you’ve made your first batch you’ll have your own kombucha to use as a starter on the next batch.

Pour the cool tea into the bowl.
Make sure your tea is cool before you add it to the kombucha culture! Hot tea can kill the culture. It should be no more than blood heat before you add it to your starter.

Add the kombucha scoby.
Pick up your scoby and slide it into the bowl. It will probably float but sometimes they sink. It will make no difference if it floats or sinks so don’t worry about it. If the scoby has a 'dirty' side where it's darker in colour and has beard like brown bits sticking to it then put that side facing down into the tea. The brown bits are yeasts.

Cover it and leave it to ferment

Put your tea towel over the bowl and secure it with a rubber band or a piece of elastic. This keeps contamination out of your culture. Fruit flies especially like the smell of kombucha and can appear like magic out of thin air to lay their eggs in the scoby. So it’s important to cover it properly.

Put the bowl in a warm dark place (23°-30°C or 70°-86°F) like an airing cupboard or in a kitchen cupboard or near a radiator. 
And that’s it!

Checking The Brew

The fermentation will take 5-14 days depending on the temperature. If you check your brew after 2 or 3 days you’ll notice a film forming on the surface. It’s not scum at all; it’s the first thin membrane of your new kombucha scoby.

Start tasting the brew after 4 or 5 days. Gently move the scoby aside and dip a spoon in to the liquid. When the kombucha is ready it should be neither too sweet nor too sour. This is rather a personal taste and will depend on how much sugar you want left in the brew. Some like it sweet but others prefer it sour. It’s up to you, so test it daily until its the way you like it.

In this close up the new scoby is lifted off the surface of the kombucha so you can see how thin and transparent it is compared to the starter scoby at the bottom of the photo. The yellow sediment floating in the brew are yeasts and quite natural.

Bottling
When the kombucha is ready, with clean hands gently lift the mother culture and it’s offspring out onto a clean plate.

Strain the kombucha into your measuring jug leaving behind about 200ml in the bowl as a starter for the next batch.

Now fill your clean bottles with the kombucha, label them and store them in a cupboard or the fridge. You can use any kinds of bottles but some batches will be a lot fizzier than others and it's a good idea to use pop bottles, like the Grolsh bottles, that have rubber gaskets on them. This kind of bottle will let out any excess pressure and prevent explosions!

After bottling your kombucha make up a second batch of tea for the culture and set your second brew to ferment.

Kombucha is ready to drink immediately, but storing the bottled kombucha for a month or two will give you will give you an even better drink. This kind of bottle conditioning can improve the flavour as any home wine brewer will know. The sugar continues to ferment a little, giving you lighter, drier taste and producing more fizz.

The kombucha will often grow little scobys on the top of the liquid in the bottles. This is perfectly normal and nothing to worry about but look out for them when you take your first mouthful!

You are now ready to drink your first home made kombucha!
Cheers!

The Next Batch
Now you can make a second batch of sweet tea and when it’s cool add it to the bowl and the waiting starter. Then add your scoby and put the tea towel back over the bowl and put the bowl away to ferment.

For your first 2 or 3 batches it’s a good idea to use both the mother and the baby together until the new scoby thickens up. When they are new they can be paper thin. With each brewing a new layer will form on top and your scoby will get thicker. Then, when it's somewhere between a quarter and a half an inch thick, you can gently separate the mother and baby and use the mother to start off a second brew.

Each scoby will grow with each brew, gradually getting thicker. You can leave them like this and occasionally peel of a layer from the bottom and discard it. Or you can separate them and either pass new scobys on to friends or store them as spares in another jar of sweet tea which you can keep in the fridge to slow down fermentation. It’s useful to have spares in case your active culture becomes contaminated and you need to discard the kombucha and the scoby and start again.

Notes and Variations

Containers
The kombucha culture needs oxygen for the fermentation. A Pyrex bowl gives a large surface area and is an excellent brewing container. But you can use taller jars to brew the kombucha, it will simply take longer to brew because there's a smaller surface area exposed to oxygen. So 5-10 days in a bowl becomes more like 10-20 days in a jar.

Several brewing suppliers now carry kombucha fermenting jars They are wide mouthed jars, usually sat in a wicker container that helps to keep the light out. A 3 litre pickle or sweet jar will do very well too.