Aitor over at [[Old School Bakehouse]] gave me some tips on how they prepare the cold brew. The ratio he uses is **50g per 1L of water**, using the same nylon bag setup I use at home. Since he uses very high quality coffees, he recommended to **always increase the time it brews and keep the ratio**, so that more special coffees can indeed last for more brews. A good default is 16-20h depending on what you want from the cold brew, and longer than 24h shows diminishing returns.