Dissolve yeast in warm water - 105° to 115° F in a measuring cup or small bowl; set aside (it will become foamy). Sift together flour and baking soda in a large bowl; set aside.
Combine buttermilk - 90° to 105° F, sugar, oil and salt in a medium bowl. Add dissolved yeast mixture; stir to blend. Add flour mixture; mix well. Let stand for 10 minutes.
Grease a 12-cup muffin tin; divide dough into 36 small portions, forming into balls; place three balls in each muffin cup. Brush with melted butter. Let stand for 30 minutes. Bake at 425° F for 10 to 12 minutes.
Servings: 12 rolls