The first Western modifications of coffee brewing date from around 1700, when French cooks isolated the solid beans within the liquid by enclosing the grounds in a cloth bag, and thus produced a clearer, less gritty brew. Around 1750, the French came up with the most important advance before espresso: the drip pot, in which hot water was poured onto a bed of grounds and allowed to pass through into a separate chamber. This invention did three things: it kept the temperature of the extracting water below the boil, it limited the contact time between water and ground coffee to a matter of a few minutes, and it produced a sedimentless brew that would keep for a while without getting stronger. The limits on brewing temperature and time meant a less complete extraction of the coffee. This reduced the bitterness and astringency, and allowed the other elements of coffee flavor more prominence, the tartness and aroma that were more appealing to European tastes.