01 - Pour whole milk into a saucepan and heat over medium heat, stirring occasionally to prevent scorching, until temperature reaches 180°F.
02 - Remove saucepan from heat and allow milk to cool down to 110°F, checking temperature periodically.
03 - In a small bowl, whisk together 2 tablespoons of the cooled milk with the plain yogurt starter until completely smooth.
04 - Pour the starter mixture back into the cooled milk and stir gently but thoroughly to distribute evenly.
05 - Transfer mixture to a clean container, cover securely, and wrap in a towel or place in a yogurt maker. Let culture undisturbed in a warm location for 6 to 8 hours until set.
06 - Line a strainer with cheesecloth and place over a bowl. Pour the set yogurt into the strainer and refrigerate for 1 to 2 hours until thickened to desired consistency.
07 - Transfer thickened yogurt to a clean airtight container. Refrigerate until ready to serve.