Making your own yoghurt feels like a bit of magic the first time: a litre of milk and a spoonful of live yoghurt, and by morning you have a whole tub of thick, tangy yoghurt. Once you've done it once, you can keep it going indefinitely.
It all comes down to two temperatures, one to thicken the milk and one the bacteria live at, and a warm, still place to set. The recipe is below, with more on how it works underneath it.
How to Make Yoghurt at Home: A UK Guide
Makes About 1 litre; needs 8 to 12 hours to set
Makes
About 1 litre; needs 8 to 12 hours to set
Ingredients
Method
- 1
Warm the milk gently to 82 to 85°C, stirring so it doesn't catch, and hold it there for about a minute. This is what makes the yoghurt thick.
- 2
Cool it to 43°C. A bowl of iced water speeds this up, and a thermometer is essential here, because too hot kills the culture and too cool stalls it.
- 3
Whisk the live yoghurt into a little of the warm milk, then stir that back through the rest.
- 4
Pour into a warmed flask, clean jars or a bowl.
- 5
Keep it at around 43°C, undisturbed, for 8 to 12 hours. An oven with the light on, a warmed flask, or a bowl wrapped in a towel in a warm spot all work. Don't stir or move it while it sets.
- 6
Once set, chill it for at least 4 hours before eating, as it firms up further as it cools.
- 7
For Greek-style yoghurt, strain it through a muslin-lined sieve in the fridge for 2 to 3 hours.
Cook’s notes
- Hands-on time is about 20 minutes; the rest is the milk setting on its own for 8 to 12 hours.
- Whole milk sets thickest. Semi-skimmed works but is looser, and skimmed thinner still.
- Save 2 tablespoons of this batch to start your next one, a free culture you can keep going. Refresh it with new live yoghurt every few batches if the set weakens.
- Avoid UHT or long-life milk if you can, as it sets poorly.
- Use a thermometer and scrupulously clean equipment: yoghurt is a live culture, so stray microbes from dirty jars or spoons cause off-flavours. The hot step also pasteurises the milk.
- It keeps 1 to 2 weeks refrigerated in a sealed container.
What you’ll need
- Kitchen thermometer, the two temperatures are the whole game
- Heavy pan
- A warmed flask, clean jars or a bowl, to incubate
- Muslin, optional, for Greek-style
Troubleshooting
It came out thin and runny.
Heat the milk hotter next time and hold it steady at 43°C. To rescue this batch, strain it through muslin to thicken it.
It's grainy or split.
You used too much starter, or the temperature swung during incubation. Use no more than 2 tablespoons per litre and keep the warmth steady.
It never set.
The milk was too hot when you added the culture and killed it. Check with a thermometer and re-culture at 43°C.
It's too sour.
It incubated too long or too warm. Shorten the time to 4 to 6 hours and keep to the cooler end of the range.
It smells off or unpleasant.
Discard it. An off smell means contamination, not fermentation, so start again with clean equipment.
More about making yoghurt
It's built on two temperatures. The hot step, around 82 to 85°C, restructures the milk proteins so the finished yoghurt is thick and holds together. The cool-down to about 43°C is the temperature the bacteria actually live and work at.
Get the second temperature wrong and nothing happens. Add the culture above about 46°C and you cook the bacteria; below about 38°C they go dormant and the milk stays liquid. A thermometer takes the guesswork out.
Yoghurt is alive. Two bacteria feed on the milk sugar and turn it into lactic acid, and that acid is what thickens the milk and gives it the tang.
Warmth and stillness do the work. Once cultured, it just needs to sit undisturbed in gentle, steady heat for several hours. At that stage you're an insulator, not a cook.
It's a perpetual culture. Every batch contains living starter for the next, so a single pot of shop yoghurt can seed an endless chain, refreshed occasionally to keep it lively.
Frequently asked questions
Written by
UK Homesteading Team
Editorial team
The UK Homesteading editorial team, offering UK-specific, evidence-led guidance on growing, keeping, preserving and the law.
