Slow Cooker Yogurt

Prepare the Jars: Place four 10-ounce jars in your slow cooker. Fill the slow cooker with water until it reaches about 1/3 inch from the jar rims. Remove the jars and set them aside. (Prep time: 5 minutes)

Preheat the Slow Cooker: Cover the slow cooker and preheat it on High for approximately 20 minutes. This ensures a consistent starting temperature. (Time: 20 minutes)

Prepare the Milk Mixture: In a saucepan, combine the milk and powdered milk. Whisk thoroughly to dissolve any lumps. Heat the mixture over medium heat, stirring frequently, until it reaches a steaming point and a thermometer registers 179°F (82°C). (Time: 10 minutes)

Cool the Milk Mixture: Remove the saucepan from the heat and place its bottom into a bowl filled with ice water. Continue stirring the milk mixture until the temperature cools down to 114°F (46°C). This rapid cooling is crucial for maintaining the yogurt's texture. (Time: 15-20 minutes)

Incorporate the Yogurt Culture: Measure out about 1 cup of the cooled milk mixture and pour it into a separate bowl. Add the plain yogurt (with active cultures) and stir until completely blended. Return this yogurt mixture to the remaining milk in the saucepan and stir gently to combine. (Time: 5 minutes)

Fill the Jars: Carefully pour the milk-yogurt mixture into the four glass jars, filling them to within about 1/2 inch of the rims. (Time: 5 minutes)

Incubate in the Slow Cooker: Ensure the water temperature in the slow cooker is no higher than 114°F (46°C). If cooler, cover and allow to warm up. If too hot, uncover and turn off the slow cooker to let it cool slightly. Gently place the filled jars into the warm water, ensuring the water level is aligned with the yogurt level in the jars. Cover the slow cooker with a folded dish towel and then secure the lid on top. (Time: 5 minutes)

Incubation Period: Turn the slow cooker off. Let the yogurt set for 6 hours, maintaining the water temperature as close to 114°F (46°C) as possible. Check the temperature after 2 hours; if it has dropped below 114°F (46°C), turn the slow cooker to Warm for 10 minutes, then turn it off again. Repeat this temperature check at the 4-hour mark. Avoid stirring or disturbing the yogurt during this time. (Time: 6 hours)

Check for Readiness: After 6 hours, gently press the top of the yogurt or tilt the jars to check if it has set. It is ready when the yogurt is firm and a thin layer of yellowish liquid (whey) has formed on top. (Time: 2 minutes)

Chill and Store: Remove the jars from the water and dry them thoroughly. Seal them with clean lids and refrigerate. The yogurt will keep for up to 2 weeks.