Gather equipment: saucepan, thermometer, whisk/spoon, clean jar(s) with lid, ladle, towels or heating pad (optional), cooling rack or bowl
Gather ingredients: milk (whole/2% works best), plain yogurt with live active cultures (or yogurt starter), optional powdered milk (for thicker yogurt)
Sanitize jars and utensils
Heat milk to 180–185°F (82–85°C)
Hold at 180–185°F for 5–10 minutes
Cool milk to 110–115°F (43–46°C)
Stir in yogurt starter: use 2–4 tablespoons yogurt per quart (1 liter) of milk
Mix until fully combined
Pour into jars
Incubate at 110–115°F (43–46°C) for 6–12 hours until set and tangy
Check after 6 hours; longer incubation yields tangier yogurt
Stop incubation by refrigerating at least 4 hours
For thicker yogurt: use more starter, incubate longer, or strain through cheesecloth after chilling
Reserve 2–4 tablespoons of finished yogurt for the next batch (best within 3–5 generations)
Store refrigerated yogurt up to 1–2 weeks