Perfect Plain Low-Fat Yogurt

Directions

1. 1
   Heat milk to scalding point (170F; 77C) in saucepan over low heat, stirring frequently.
2. 2
   Whisk in skim milk powder, if using.
3. 3
   Remove from heat, and let cool 30 minutes to 1 hour, or until milk temperature reaches 110 to 120F (44 to 49C) on instant-read thermometer, stirring once or twice.
4. 4
   Whisk together yogurt and 1/2 cup cooled milk in bowl.
5. 5
   Whisk this mixture into remaining cooled milk.
6. 6
   Pour into clean container(s), secure lid(s), and place in yogurt maker.
7. 7
   Set timer for 8 to 10 hours.
8. 8
   (The longer yogurt ferments, the firmer its texture and tangier its flavor.)
9. 9
   Check 1 container after 8 hours; if yogurt has reached desired tartness and texture, remove cups from yogurt maker, and refrigerate.
10. 10
    If not, replace test cup, and continue to ferment 1 to 2 hours more.
11. 11
    Chill completely before serving.