El Papi’s chef and owner preserved his dish for six days before serving it. Yes, he calls it aging, as if his birria were porter steaks slowly losing moisture in a temperature- and humidity-controlled room. One afternoon, Zamora-Herrera walked me through his birria-making process: It involved braising brisket for hours, removing the meat, and using braised beef as the base for a carefully prepared dish with over 20 spices, herbs and other ingredients, including ground annatto seeds, ginger and banana leaves lightly fried in brisket. Oh, by the way, Zamora-Herrera likes to get rid of most, if not all, of the fat in the stew. Do not skim in your kitchen.
https://www.washingtonpost.com/food/2021/11/16/birria-in-dc/ | Where to find birria in the DC area: Little Miner Taco, La Tingeria, El Papi Street Tacos, Tacos Don Perez