Combine yeast, ¼ cup milk, and 1 ½ tablespoons flour in a small bowl to make a yeast sponge. Cover and let stand 30 to 60 minutes, until mixture begins to bubble.
Combine yeast sponge, butter, and eggs. Blend in 1 cup milk and salt.
Stir in enough remaining flour to make a soft bread dough.
Lightly knead on floured board 5 minutes.
Cover and let rise in bowl about 1 hour.
Shape into 4 oval loaves.
Lightly flour tops; cover and let rise 1 hour.
Drop into large pot of boiling water; dumplings should not touch each other while cooking.
Cover immediately and cook 8 to 10 minutes. Do not uncover while cooking.
Remove with slotted spoon; drain and slice with thread.