Pour the milk into a large saucepan.
8 cups 2% or whole milk
Heat the milk over medium heat until it reaches 185°F. Use a kitchen thermometer to check the temperature.
Stir the milk occasionally to prevent a skin from forming and to ensure even heating.Remove the saucepan from the heat.
Allow the milk to cool down to 110°F. Tip: To speed up the cooling process, you can place the saucepan in an ice bath.
Once the milk has cooled to 110°F, take about 1 cup of the milk and mix it with the yogurt in a small bowl until smooth.
½ cup plain yogurt with live active cultures
Pour this mixture back into the saucepan and stir gently to combine.
Pour the milk mixture into a container or bowl. Cover it with a lid or a clean kitchen towel.
Place the container in a warm environment where it can maintain a temperature of about 110°F. You can use an oven with the light on, a yogurt maker, or a warm spot in your kitchen.
Let the mixture incubate for 6-12 hours, depending on how tangy you like your yogurt. The longer it incubates, the tangier it will be. After the incubation period, the mixture should have thickened into yogurt.
To make Greek yogurt, strain the yogurt to remove excess whey. Place a cheesecloth or a clean kitchen towel over a fine mesh strainer, and set it over a bowl.
Pour the yogurt into the strainer and let it drain for at least 2 hours, or until it reaches your desired thickness.
Store it in the refrigerator and consume within 1-2 weeks.