Historically, the style of beer that can be brewed in a region has both benefited from and been limited by local water quality. The water in Ireland, for example, is rich in calcium ions and bicarbonate, balanced by the acidity of roasted barley, which makes for a dry world. The water in the Pilsen region of the Czech Republic is extremely soft and contains almost no mineral salt, giving rise to the Bohemian Style of Pilsen. The water in Bolton Trent is extremely hard and rich in calcium sulfate and bicarbonate, which aggravates the bitter taste of hops and makes the mouth plump and dry, resulting in the British IPA.