da qu
From The Oxford Companion to Spirits & Cocktails
(“big qu”) is a type of solid-state fermentation starter made from wheat or barley (sometimes supplemented by peas) used in the production of the Chinese spirit baijiu. See also baijiu, qu.
This definition is from The Oxford Companion to Spirits & Cocktails, edited by David Wondrich (Editor-in-Chief) and Noah Rothbaum (Associate Editor).