Preheat oven to 350ºF/175ºC. Dissolve 1 teaspoon of sugar in water, sprinkle yeast over top and let stand for 10 minutes. Combine bloomed yeast with milk and 5 cups flour. Beat well until smooth. Cover and let rise in warm place until light and bubbly (~5 minutes). Add eggs, sugar, 1/2 cup butter, and salt. Mix thoroughly. Stir in enough flour to make a dough that is neither too soft or too stiff. Let rise for 60 minutes. Turn on to a floured surface and knead for 5-10 minutes, mixing the raisins into the dough. Place back in bowl and let rise for 1 hour, until doubled in bulk. Divide and shape into loaves. Place in greased loaf pans, let rise for 1 hour until doubles in bulk. Bake 30-45 minutes until golden brown. Serve.