In a large stew pot heat milk to 185 degrees. While heating stir in cream, sugar and powdered milk. Whisk to dissolve ingredients thoroughly. Stir constantly and check temperature with a good instant reading thermometer.

When mixture reaches 185 degrees, remove from heat. To speed cooling, immerse pot in a sink filled with cold water. Make sure to avoid letting sink water get in the mixture. Stir constantly until mixture cools to exactly 115 degrees.

At this point, add entire jar of yogurt. Any hotter than 115 degrees will kill the yogurt cultures and ruin this batch of yogurt.

Gently whisk until yogurt is thoroughly blended. Add vanilla and blend.

Transfer mixture to Instant Pot and choose “Yogurt” program setting. Set timer for 8 hours and press start.

After 8 hours and no more, stir yogurt about 45 seconds and fill sterilized jars. Seal and refrigerate immediately. Let chill for at least 4 hours before tasting.