How to Make Greek Yogurt at Home: Step-by-Step Method, Timings and Troubleshooting
Homemade strained yogurt is one of the few kitchen projects that is cheaper, better and more interesting than the shop version. You need milk, a spoonful of live yogurt as a starter, a thermometer and a clean cloth. The active work is about twenty minutes; the rest is waiting.
What you need
Ingredients (makes roughly 350–450 g strained yogurt)
1 litre whole milk (3.5% fat). Semi-skimmed works; skimmed gives a chalkier result. Sheep's or goat's milk makes a richer, more traditional yogurt.
2 tablespoons (about 30 g) plain live yogurt with no additives, as starter. Shop-bought strained yogurt listing only milk and cultures is ideal. From the second batch on, use your own.
Equipment
Heavy-based saucepan
Kitchen thermometer (the temperatures matter)
Glass or ceramic bowl with a lid, or a large jar
Clean cotton cloth (muslin, cheesecloth or a thin tea towel) and a sieve
Somewhere warm: a switched-off oven with the light on, an insulated box, or a yogurt maker
Method
Heat the milk to 85 °C. Warm it slowly, stirring so it does not catch. Hold at 82–85 °C for 5–10 minutes. This step is not only about safety; it unfolds the whey proteins so they bind into the gel, which is what gives homemade yogurt a firm set rather than a grainy one. Skipping it is the most common cause of thin yogurt.
Cool to 45 °C. Stand the pan in cold water to speed this up. Above 50 °C the starter bacteria die; below 40 °C they work too slowly. Remove any skin that forms.
Add the starter. Mix the two tablespoons of yogurt with a ladle of the warm milk until smooth, then stir it into the pan. Gentle stirring, not whisking.
Incubate 6–10 hours at 40–45 °C. Pour into the bowl or jar, cover, and keep it warm and still. Do not stir or move it. At 6 hours you get a mild set; at 10 hours a tangier one. Overnight is convenient. The yogurt is ready when it jiggles as one mass and pulls slightly from the side when tilted.
Chill for 2 hours (optional but useful). Cold yogurt strains more cleanly and the whey runs clearer.
Strain. Line the sieve with the cloth, set it over a deep bowl, pour in the yogurt, fold the cloth over and put it in the fridge. For Greek-yogurt thickness, strain 4–6 hours. For labneh-style spreadable yogurt, 12–24 hours. You can also tie the cloth and hang it from a shelf over the bowl, which is how village yogurt was drained.
Scrape, whisk, store. Scrape the yogurt off the cloth, whisk briefly for a smooth texture, and keep it in a covered container in the fridge.
What to expect
Yield. One litre of milk gives around 900 g of set yogurt and, after 4–6 hours of straining, 350–450 g of Greek-style thickness plus 450–550 ml of whey. That ratio, roughly three to one, is the same one commercial dairies live with.
Taste. Milder and creamier than most shop yogurt on day one, sharpening over the week as the cultures keep working.
Keeping. 7–10 days refrigerated at 4 °C or below. Keep 2 tablespoons back as the next starter within the first few days, while the culture is at its most active.
Troubleshooting
Problem | Likely cause | Fix |
Thin, won't set | Milk not heated to 85 °C; starter added too hot or too cold; incubation too cool or too short | Hit the temperatures; incubate longer; check the starter has live cultures |
Grainy or lumpy | Milk scorched; temperature swung during incubation; stirred while setting | Heat gently; keep still; strain and whisk afterwards |
Very sour | Incubated too long or too warm | Shorten to 6 hours; chill promptly |
Slimy or stringy | Starter culture producing exopolysaccharides, often after many generations | Start again with fresh shop yogurt |
Pink, orange or fuzzy spots; off smell | Contamination | Discard. Sterilise equipment with boiling water next time |
Lots of whey pooling in the tub | Normal syneresis | Stir it back in, or pour it off |
Using the whey
The liquid you drain off is acid whey: slightly sour, cloudy, rich in lactose and minerals and low in protein. Do not pour it down the drain in quantity if you can avoid it; use it for:
the liquid in bread, pancake or pizza dough (it tenderises)
soaking oats or grains overnight
a brine or marinade for chicken (the acid works like buttermilk)
watering acid-loving plants, diluted
a sour note in smoothies or lemonade
Commercial dairies face the same question at a scale of millions of litres; see Acid whey: Greek yogurt's byproduct problem.
Variations
Sheep's milk yogurt. Same method; incubation may be slightly shorter because of the higher solids. Expect a thicker, sweeter result with a distinct aroma.
Traditional set yogurt with skin (paradosiako). Pour the inoculated milk into individual clay or glass pots and incubate uncovered under a loose cloth; the skin forms during setting. Do not strain.
Higher protein without straining as long. Start with milk fortified with 2–3 tablespoons of skimmed milk powder per litre. Note that in Greece this would not legally be "yogurt", but at home it is simply a shortcut.
Using a yogurt maker or Instant Pot. Follow the same temperatures; the appliance only replaces the "somewhere warm" step.
Why bother
Beyond cost, the appeal is control: fat level, tang, thickness and ingredients are all yours, and a litre of good milk becomes a food that feeds a household breakfast for days. For what to do with it, see Cooking and baking with Greek yogurt and Greek yogurt with honey and walnuts.
Recipe notes and safety. Quantities are guidelines; adjust to taste. This recipe contains milk; check the ingredients you add for other allergens. Use pasteurised milk unless you are confident in the source and heat raw milk to at least 85 °C as described. Keep yogurt refrigerated at or below 4 °C, discard anything with mould, pink or orange discolouration or an off smell, and do not give honey to infants under 12 months. Nutrition figures, where given, are estimates and not a substitute for a label or professional advice.
Sources
Dairy (MDPI) 2025, 6, 21 — strained yogurt yields and acid whey composition: mdpi-res.com (PDF)
Greek Food and Beverages Code, Article 82 — definitions of strained and traditional yogurt and required cultures: aade.gr (PDF)
EFSA Journal 2010;8(10):1763 — live yogurt cultures and lactose digestion: efsa.europa.eu
Wikipedia, Yogurt (fermentation temperatures and culture biology overview): en.wikipedia.org
Comments