The quality of the water is fundamental for the obtaining of a good coffee. The calcárea water gives a hard and bitter coffee. Therefore, it agrees to use mineral water with low content of calcium (certain waters of spring), or running water purified by a descalcificador. Another solution consists of filtering the water in a container with removable filters. This process presents/displays the advantage to filter the scents and the impurities, at the same time that the water decalcifies. The professionals use generally an automatic descalcificador completed by a filter that eliminates the scent chlorine or ozone, particularly frequent during the warm stations, of the water “ of the faucet ”. A great always effective principle: the water does not have to really boil. A water on the verge of boiling is due to use, between 92° and 95° C.