Yogurt Recipe

Sanitize equipment

Wash a heavy-bottomed saucepan, a wooden spoon or heatproof spatula, a whisk, a glass or ceramic bowl (or jars), and a thermometer in hot soapy water. Rinse well to remove soap. This reduces contamination and helps the yogurt set properly.

Heat the milk

Pour 1 liter whole milk into the saucepan and set over medium heat. Stir occasionally to prevent a skin from forming and to avoid scorching. Heat until the milk reaches 82°C (180°F) or until it just begins to steam and small bubbles form around the edge, about 8–12 minutes depending on stovetop.

Cool the milk

Remove the pan from heat and let the milk cool to 43–46°C (110–115°F). Stir occasionally to help it cool evenly; this takes about 20–30 minutes. Use a clean thermometer to check temperature. If you don't have a thermometer, the milk should feel warm but not hot to the inside of your wrist.

Prepare the starter

Place 2 tablespoons of plain active yogurt in a small bowl. Add 2–3 tablespoons of the warm milk and whisk until smooth. This tempers the starter so it incorporates evenly into the larger batch.

Inoculate the milk

Pour the tempered starter back into the cooled milk and whisk gently until fully combined. Ensure the milk temperature is still around 43–46°C (110–115°F) when you add the starter; if it's much cooler the cultures may not activate reliably.

Incubate

Transfer the inoculated milk into a clean glass or ceramic container or divide into jars. Maintain a steady warm environment of about 40–45°C (105–113°F) for 4–8 hours depending on desired thickness and tang. Options for incubation: - Oven method: preheat oven to the lowest setting for 2 minutes, turn it off, place the covered container inside with the oven light on. - Yogurt maker: follow manufacturer instructions. - Insulated cooler: wrap jars in towels and place in an insulated cooler with a warm water bottle. Check after 4 hours; the yogurt should look set and slightly jiggly. Longer incubation (6–8+ hours) yields tangier, thicker yogurt.

Cool and set

Once set to your liking, move the yogurt to the refrigerator and chill at least 2–4 hours to fully firm up. Refrigeration also slows culture activity and mellows the flavor.

If you want sweetened or flavored yogurt, stir in up to 2 teaspoons of sugar or honey, 1 teaspoon vanilla extract, and a pinch of salt to the chilled yogurt to taste. For fruit or jam, fold in 1/2 cup fresh fruit or 1/2 cup jam per liter of yogurt or serve on the side.

For thicker Greek-style yogurt, strain the chilled yogurt through a cheesecloth-lined fine-mesh sieve over a bowl in the refrigerator for 2–4 hours until it reaches desired thickness. Reserve whey for smoothies or baking.

Store finished yogurt in airtight containers in the refrigerator for up to 1–2 weeks. Use a clean spoon each time to extend shelf life.