Proof the yeast in the lukewarm water with the sugar.
After you get a yeast sponge add the buttermilk (room temperature), salt, eggs and the three different kinds of flour and caraway seeds.
Take the dough out onto a lightly floured work surface, kneading until smooth.
Place the dough in a large buttered bowl, cover with a towel and let stand in a warm place to rise until doubled in bulk.
This will take from 1~/2 to 2 hours.
Take the dough out and punch it down a couple of times.
Knead and shape the dough into a loaf and place in a buttered loaf pan (9~ by 5~). Let stand in a warm place, covered with a towel, to rise for about 1 hour or until doubled in size. Preheat the oven to 400 degrees. Brush the bread with a little melted butter and bake in the oven for about 30 minutes or until light brown and the bread sounds hollow when tapped with your finger.