was over the moon when a friend gave me my first scoby (a symbiotic colony of bacteria and yeast), because it meant I could finally make kombucha at home. Kombucha is, essentially, a fermented iced tea that can be flavoured with just about anything, making it a great way to use up fruit and vegetable scraps. It originated in China and is now increasingly popular in western culture. A healthy scoby will double in size each time you make kombucha, so it is easy to share with friends and fellow fermenters. Also, any excess scoby can be cut into cubes and boiled up with sugar to make a candy called nata. Kombucha flavoured with scraps Making your own kombucha saves waste – and money – and provides you with a powerful tonic to replace sugary drinks. You will need to get hold of a scoby, which sits on top of the tea as it ferments: ask around friends or order one online. You will also need a five-litre jar or crock and clean, sterilised bottles with lids. Makes 4 litres 260g unrefined sugar, plus 2 tsp per litre extra for the secondary fermentation 4 tbsp black, green or white tea 500ml mature kombucha (or 2 tbsp raw apple cider vinegar) 1 scoby (or kombucha mother) Dissolve the sugar in a litre of boiling water, mix in the tea and leave to brew for 20 minutes. Pour three litres of cold water into a five-litre fermentation jar and strain in the tea. Add the kombucha (or cider vinegar), rest the scoby on top and cover. Store away from direct sunlight for a week, then taste: when ready, the kombucha should be lively and effervescent, with a balanced, gentle sweet-and-sourness. When it is to your taste, bottle all but 500ml and the scoby, which can be used to make your next batch. Once the kombucha is bottled, add two teaspoons of sugar to each litre bottle, then seal and leave at room temperature to continue fermenting. To prevent the kombucha from becoming too carbonated, which can cause the bottles to explode, open each bottle once a day to let excess gas escape. Taste daily to check the fizz. Once ready (after two to six days), consume or store in the fridge. During this secondary fermentation, you can flavour the kombucha by adding fruit and veg scraps and spices: some flavour combinations I particularly like are spent citrus rinds and root ginger peel; apple scraps with cinnamon; orange peel and dandelion flowers; and fennel tops with mint.