Chefs and beverage directors agree, and that's why more and more drink lists across the United States are starting to include a Basque cider or two. Leading the charge is Txikito, the acclaimed Basque restaurant in Chelsea from chefs and owners Alex Raij and Eder Montero. On a recent Sunday evening in early spring, Raij and Montero transformed Txikito into a pop-up sagardotegi, the cider houses unique to the Spanish Basque country. Since the 11th century when Basque cider makers first began fermenting apples into potent beverages, sagardotegiak have sat at the core of Basque culture. Every year from January to May, Basque cider houses fling open their doors, inviting guests to savor the first ciders of the season, to eat, sing, and make music together as a unified, thirst-quenched community. Central to this merriment is the txotx (pronounced "choke"), the centuries-old Basque cider house ritual of tapping a new barrel of cider. Once the tap is released, sending cider streaming out of the barrel like a fountain, drinkers rush to thrust their cups under the tap before any cider can hit the ground. The ritual feels sacred.