I’m quite fond of carbonated water, and last summer I bought a water carbonator so I wouldn’t have to carry all the water home from the shop. The working principle of the carbonater is very simple – a bottle filled with cold tap water is subjected to a pressure of carbon dioxide for a couple of seconds, allowing some of it to dissolved in the water. The result is an instant sparkling water. But even with the carbonation there is something missing. The big difference between my homemade instant carbonated water and bottled mineral water is the mineral content. True, tap water may also contain a number of minerals, but this varies and there are huge regional differences. In Norway most water is very soft (i.e. low in calcium and magnesium) and has a very low mineral content. But tap water rarely has a desirable mix of minerals compared with the really good tasting mineral waters.