How to make kefir

What the grains are, and how kefir differs from yoghurt

Kefir grains are not a grain in any botanical sense. They are soft, cauliflower-like clusters of a polysaccharide matrix housing a stable community of lactic acid bacteria and yeasts. They grow, they can be divided, and they are passed on rather than bought each time.

That yeast component is the main difference from yoghurt. Yoghurt is bacteria alone and is simply sour; kefir is bacteria and yeast together, so it is sour, slightly fizzy, faintly yeasty and contains a trace of alcohol.

It is also thinner. Kefir pours where yoghurt spoons, and it is drunk rather than eaten.

The daily cycle

Five minutes a day. Handling and safety questions are for the Food Standards Agency.

1. Put the grains in a clean jar and cover with milk. A tablespoon of grains to a few hundred millilitres of milk is a common starting ratio.
2. Cover the jar with a cloth or a loose lid so gas can escape.
3. Leave it at room temperature for around twelve to twenty-four hours. Warmer is faster.
4. It is ready when it has thickened, smells pleasantly sour and yeasty, and small pockets of whey are beginning to separate at the edges.
5. Strain it through a plastic or stainless steel sieve — the grains stay behind. Avoid prolonged contact with reactive metals.
6. Put the grains straight into fresh milk and start again.
7. Refrigerate the finished kefir, which stops it souring further and lets it settle.

What to do with it, and what to do when things go wrong

• Drink it plain, or blended with fruit and a little honey.
• In place of buttermilk in scones, soda bread or pancakes.
• In a marinade, where the acidity tenderises gently.
• Strained through muslin into a soft kefir cheese, much like labneh.
• Over-fermented and separated into curds and whey means it went too long. Shake it, use it in baking, and strain it sooner next time.
• Grains not growing usually means the milk is too cold, or the ratio of grains to milk is too high.
• Taking a break — put the grains in fresh milk in the fridge, where they slow almost to a stop for a week or two.
• Water kefir is a different culture entirely, fermenting sugar water rather than milk, and it is dairy-free.

Notes

Getting grains

From somebody who already has them, or dried from a supplier. They multiply, so most people who make kefir have spares.

Milk

Full-fat cow's milk is the standard. Goat and sheep milk work. Plant milks do not sustain the grains long-term.

Metal

Brief contact with stainless steel is fine. Avoid aluminium and prolonged contact with reactive metals.

Speed

Twelve hours in a warm kitchen, twenty-four in a cold one. Taste rather than clock-watch.

Alcohol

Kefir contains a trace of alcohol from the yeast — typically a fraction of a per cent, and more the longer it ferments.

Common questions