Yesterday, I heard a friend sing a song about the Dragon Boat Festival. What does this mean?

It is a traditional process, which should be the brewing process of maotai-flavor liquor. Every year during the Dragon Boat Festival, distiller's yeast is made from wheat. The quality of koji is directly related to the quality and taste of wine. Because the temperature of Dragon Boat Festival is higher, it is more conducive to the growth of brewing microorganisms, so it is the best time to make koji with soy sauce. The general steps are as follows: firstly, wheat is crushed, mixed with water and "mother yeast" and put in a wooden box. The worker stood in the box, kept stepping on it with his feet, made it into a "curved block", wrapped it with straw, then "stored it" and turned it over. In short, it's complicated. For example, Langjiu, Lanhualang and Maotai all went through this koji-making process, and the maotai-flavor wine brewed was of better quality and taste.