Water kefir
Milk kefir
Kombucha
Ginger beer
Kefir duo
Kefir and kombucha
Starter kit
RennetKombucha vinegar is kombucha that has stood in the open jar for so long that all the sweetness has gone. Brew a batch with the basic recipe (1 SCOBY, about 250 ml of starter liquid, 80 g of sugar and 3 tea bags to 1 litre of water) and simply let it carry on past day 10, covered with a cloth, until it smells and tastes sharply sour. That takes a few weeks. Strain it, pour it into a clean bottle and use it in dressings, quick pickles and to deglaze a pan.
How does kombucha become vinegar?
By letting the acetic acid bacteria in your SCOBY carry on with their work. They turn the alcohol the yeasts make into acid, and that continues until there is almost nothing left to convert.
In the first 7 to 10 days you taste that process as freshness: the kombucha is still lightly sweet, with a clean sharpness. Leave it, and the balance keeps shifting. After two or three weeks the sweetness has gone and the jar smells like cider vinegar. That is the moment the drinkers lose interest and the cooks start paying attention. Why a jar turns sour, and how to avoid it with your everyday batches, is in Kombucha too sour?
What you need
- A jar of kombucha that has gone too sour, or a new batch made with the basic recipe from How to make kombucha.
- A SCOBY. A spare layer from your stack is ideal, so your main SCOBY keeps working on kombucha for drinking. More on that in Too many SCOBYs?
- A glass jar, a clean cloth and an elastic band.
- Clean glass bottles with a cork or cap for the finished vinegar.
The method, step by step
1. Set up or choose a jar
Use a jar that is already too sour, or start a new litre with 80 g of sugar, 3 tea bags, a SCOBY and about 250 ml of starter liquid.
2. Let it carry on
Cover with a cloth and an elastic band, never a lid: the bacteria need air. Put the jar somewhere quiet at 20 to 25°C, out of the sun.
3. Taste once a week
Use a clean straw. When there is no sweetness left at all and the smell catches your nose, your vinegar is ready. Count on a few weeks.
4. Strain and bottle
Lift out the SCOBY, strain the vinegar through a fine sieve or a coffee filter and pour it into clean bottles. Keep them somewhere cool and dark.
How to flavour it
Once strained, you can flavour the vinegar the way you would make any herb vinegar.
| Flavour | What to add | Good with |
|---|---|---|
| Herb vinegar | A few sprigs of tarragon, thyme or rosemary | Dressings, chicken, roast vegetables |
| Raspberry vinegar | A handful of raspberries or blackberries | Beetroot and walnut salad |
| Apple vinegar | The peels and cores of a few apples | Red cabbage, pork, stews |
| Garlic and chilli | A clove of garlic and a dried chilli | Stir-fries, marinades |
Leave the flavourings in the bottle for a week, then strain them out. Taste along the way: herbs can take over quickly.
What to do with it in the kitchen
- Vinaigrette: one part kombucha vinegar to three parts oil, a teaspoon of mustard, a little honey, salt and pepper. The full recipe is the kombucha vinaigrette.
- Quick pickles: thin rings of red onion or slices of cucumber, an hour in kombucha vinegar with a pinch of sugar and salt. Lovely in a sandwich or beside a plate of cold ham.
- Deglazing: a splash in the pan after frying meat or mushrooms, for a fresh, sharp sauce.
- Red cabbage: instead of ordinary vinegar, for a slightly fruitier note. It earns its place on the table at Christmas.
- Chips: a shake over a bag of chips, if you fancy a gentler, fruitier version of the usual.
- Marinade: with oil, garlic and herbs, for chicken or vegetables.
Kombucha vinegar is mild and its strength varies from jar to jar. For preserves that have to keep for a long time outside the fridge, such as jars of pickled onions for the cupboard, use ordinary shop vinegar with the acidity printed on the label. For anything you will eat within a few days, your own vinegar is perfect.
How long does kombucha vinegar keep?
A long time. Vinegar is acidic enough to keep for months in a closed bottle somewhere cool and dark. A new thin skin or some sediment may form; that is normal and can be strained out. If you see fuzzy, coloured spots, throw it out, just as you would with kombucha. What is normal and what is not is in Kombucha: mould or normal?
Getting started
With a live kombucha SCOBY and its starter liquid for £16, you make kombucha to drink, and with the extra layers that grow by themselves, your own vinegar. Standard tracked delivery in the UK is £4.90 and free from £35, and all prices include VAT. Brewing, bottling and care are all on the kombucha page.