A simple device called Coravin makes it possible for sommeliers to pour rare wines by the glass because the cork is only punctured, not removed. After the desired amount of wine is extracted, a capsule of argon gas fills the bottle chamber, ensuring no oxygen gets in. Coravin culture in DC began in 2013 with top-tier restaurants like Minibar by José Andrés and Rasika by Ashok Bajaj. But, just as concepts such as tasting menus have trickled down to middle-tier restaurants, so too has Coravin.