The cold-brew process is known for creating smooth, low-acid coffee. In cold-brewing, you replace heat with time. Rainmaker technology evenly distributes cold water for optimal flavor extraction. Choose our favorite coffee (medium to coarse grind works best). Just add cold water. Borosilicate glass carafe. Ultra-fine mesh filter is stainless steel, reusable and easy to clean. Stopper with silicone seal keeps coffee fresh in the refrigerator and doubles as a measuring device. BPA-free container.