Little-known to most tourists and residents alike, there are caves full of aging cheese underneath the Crown Heights neighborhood in Brooklyn.

Crown Finish Caves is a cheese-aging facility operating in the underground vaults of the former Nassau Brewing Company, once used for aging lager beer in open barrels. Young or “green” cheeses arrive from mainly local artisan farmers, but some from as far away as Italy, and ripen in the caves.

The centuries-old process is called affinage, and it includes washing, brushing, and turning the cheese as it matures. The cheese is between 1-14 days old when it arrives, and it can take from just a few weeks to as long as a year to bring out its flavor and texture. Each cheese requires different circumstances to age ideally. The temperature in the “cheese caves,” located 30 feet below the surface, stays around 50 degrees Fahrenheit all year, regardless of the season or weather.

The aboveground part of the building, which is nearly 170 years old, has been converted to offices and workspaces, and the current owners considered honoring the building and Brooklyn’s lager heritage by aging beer or wine in the caves. Instead, they decided to convert the caves into a New York State-licensed dairy plant. The main tunnel has the capacity to hold 22,000 pounds of cheese. The beer legacy is honored, though, when they sometimes use locally brewed beers in part of their affinage process. Different beers have different effects on the cheeses.

For food safety reasons, Crown Finish Caves does not offer tours of its facilities. It does, however, host events in the non-renovated caves, where there is no cheese being aged and therefore no risk of contamination. Cheese aged in the caves can be purchased from shops all over New York City, including at various Whole Foods Market locations, and around the country, as far west as Colorado. A complete list of places to buy the cheese is available on the Crown Finish Caves website.