How to Make It
Dissolve yeast in 1/4 cup warm water in a small bowl; let stand 5 minutes.
Weigh or lightly spoon flours, potato starch, and cornstarch into dry measuring cups; level with a knife. Place flours, potato starch, cornstarch, brown sugar, and next 3 ingredients (through salt) in a large bowl; beat with a mixer at medium speed until blended. Add yeast mixture, sauerkraut, sauerkraut liquid, buttery spread, and eggs; beat at low speed until blended.
Spoon batter into a 9 x 5-inch loaf pan coated with cooking spray. Cover with plastic wrap, and let rise in a warm place (85°), free from drafts, 1 hour or until dough reaches top of pan.
Preheat oven to 400°.
Bake at 400° for 38 minutes or until loaf sounds hollow when tapped. Remove from pan; cool on a wire rack.