This Cold Brew Coffee Maker is the first of its kind. What is Cold Brew? Cold Brew is coffee prepared by soaking ground beans in cold water for several hours. Coffee brewed this way has a very delicate flavor, with low bitterness and can be stored for several days. The top is made of 100% Bpa-free, Tritan, the filter is made of 18/8 superfine stainless steel mesh to brew the purest, smoothest coffee. The bottom is an insulated bottle which ensures your coffee stays cold or hot for hours.