In a small bowl, soften yeast in water for 10 minutes. Stir well. In a 2 litre bowl, combine flour and sugar. Mix thoroughly or the flour will lump when the milk is added. Slowly stir in warm milk and softened yeast mixture. Cover loosely and let stand at room temperature until bubbly. Refrigerate. Consider this day 1 of the 10 day cycle.
Day2 through 4: Stir with a spoon (any kind) Day 5 To feed, blend flour and sugar in a small bowl; slowly mix in milk with a spoon,whisk or hand mixer. Stir mixture into starter. Return to refrigerator. Day 6 through 9: Stir Day 10 ( which becomes Day -20ºC or the next series) Feed again.
Note: Consider the 10-day cycle a guide; it does not have to be followed exactly. If you need more starter, feed it more often. The starter is a yeast culture and will grow when fed. To hasten growth, leave starter at room temp for several hours.
After feeding the starter.
Choose from among the following.
Return starter to refrigerator.
Remove what you need for baking and leave it at room temperature until very bubbly. Return remainder to refrigerector and continue to follow the 10-day cycle. If you are getting to much, cut the "food" in half on one feeding. Don't let starter drop below 1 cup, because rejuvenating it to usable amounts takes several days.
Measure out 1 cup lots to give to friends or put in the freezer.
Frozen starter takes at least 3 hours at room temperature to thaw and come to life.