Per Edible Manhattan:
As is fairly common for craft ciders, Metal House is made in the méthode champenoise tradition that builds flavor through multiple fermentations and aging directly on the lees (aka yeast cells and sediment that settle out of solution during fermentation). It’s precise work that, beginning with the fruit, is an extension of their personal philosophies.
It’s not just Gramercy Tavern that has given Metal House’s ciders a coveted spot on the beverage menu: Restaurants around the city, including hot spots like Frenchette in TriBeCa, Egg in Williamsburg, Murray’s Cheese Bar in the West Village and the aforementioned newly opened St. Julivert in Cobble Hill carry their lightly sparkling wares.