"Mashed potatoes are hefty and substantial, but in a potato rolls recipe, they give the crumb a light, tender, moist texture. That’s because the starches in potatoes dilute the gluten-forming proteins, which weakens the structural network and makes it softer, moister, and more tender. For the lightest potato rolls, we use a combination of ½ pound of mashed russet potatoes and high-protein bread flour. This creates a potato roll dough with a stable structure that supports the greatest amount of potatoes, producing rolls that were not only perfectly risen but also light and airy...."