DISSOLVE yeast in warm water (less than 100° F); DISSOLVE salt in warm milk.

In a large mixing bowl, ADD liquids; ADD flour, a cup or so at a time, while STIRRING with a wooden spoon (or use an electric mixer with a dough hook), until a sticky dough is formed (some flour will remain unused).

On a floured board, TURN out dough; KNEAD dough while ADDING remaining flour until all flour is used and dough is somewhat smooth.

Continue KNEADING dough while ADDING the butter, a tablespoon at a time; KNEAD until smooth (dough will be slightly sticky).

PUT the dough in a large bowl; COVER with plastic wrap (or a kitchen towel); let RISE until tripled in size, about 2 to 3 hours.

PUNCH dough down; KNEAD for several minutes; let RISE again until doubled in size, about 1 hour.

BUTTER inside (including lid) of a pullman (pain de mie) pan.

TRANSFER the dough to a lightly oiled bread board; DEFLATE dough gently; allow to REST for 10 minutes.

SHAPE the dough into a flat-topped log to fit the pan; PLACE in pan; COVER with lightly greased plastic wrap; let RISE until dough fills about 2/3 of pan, about 30 to 45 minutes.

Carefully PLACE cover on pan; let REST for 10 minutes; meanwhile, PREHEAT oven to 350° F.

BAKE bread for 30 minutes; REMOVE lid; BAKE for additional 10-15 minutes (internal temp should be 190° F).

REMOVE from oven; REST for 10 minutes; TURN out of pan; COVER loaf loosely with a kitchen towel to keep crust soft as it cools.