on July 22, 2016July 22, 2016Uncategorized Rare Egg Cream at Purity Diner streetbeat Leave a Comment on Rare Egg Cream at Purity Diner Purity Diner 289 7th Ave. (718) 840-0881 Purity Diner opened in 1929, and relocated to its current location 16 years ago. They offer a huge menu, that includes the hard-to-find Brooklyn soda fountain staple – Egg Cream.