This is what's left behind - lees. People who like the sweet rice wine may not like this. But some do. And some restaurants using this as condiment to give thick reddish color gravy. Some made noodle soap (mee-sua soup).
*daily dose of this in your diet could lower your bad cholesterol/LDL as it contain naturally occurring Statin found in the Red Yeast Rice that gives that reddish color...