Dissolve yeast in 1/2 cup warm water (110°-115°). In a separate bowl, combine 1 cup boiling water and shortening. Add remaining (room-temperature) water, eggs, salt, sugar and yeast mixture., Stir in 1 cup of flour at a time, mixing well after each addition, until a soft dough forms. Turn dough onto a floured surface; knead until smooth and elastic, 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and refrigerate overnight., Turn onto a lightly floured surface; divide dough into nine portions. Divide and shape each portion into 12 balls. Place 3 balls in each cup of 3 greased muffin tins. Cover with kitchen towels; let rise in a warm place until doubled, about 1 hour., Preheat oven to 375°. Brush rolls with half of melted butter; bake until golden brown, 15-20 minutes. Remove from oven; brush with remaining butter.