ANDREA GEARY
https://www.cooksillustrated.com/articles/141-the-fluffiest-dinner-rolls
The tangzhong method calls for briefly cooking a portion of the flour and water to make a paste, which is then combined with the rest of the ingredients. By using hot water, we can actually add more liquid to the dough because flour can absorb twice as much hot water as cold water. The superhydrated dough yields rolls that are not just moist but also fluffy because the water converts to steam, which acts as a leavening agent, creating rise. The extra water also increases gluten development, giving the bread the structure it needs to contain the steam rather than letting it escape.