Very light, soft and silvery shining metal or, with 2.4%, the sixth most common element (Na) in the earth's crust. Because sodium is the main component of soda (sodium carbonate), it is usually called sodium in foreign languages (as it used to be in German). It occurs in numerous minerals. A considerable amount of sodium is also dissolved in the oceans. The most important sodium compound is table salt (sodium chloride = NaCl). In plants, however, sodium plays a subordinate role. It is only needed by so-called C4 (e.g. millet, maize, sugar cane) and CAM plants (e.g. pineapple, cacti); but not by C3 plants (such as the vine). Sodium nitrate (sodium salt of nitric acid = oxygen acid of nitrogen) with the popular name Chile saltpetre is used as a fertiliser and as a preservative. Sodium is present in wine in small traces; see also under total extract.
In the past, you needed a wealth of encyclopaedias and specialist literature to keep up to date in your vinophile professional life. Today, Wine lexicon from wein.plus is one of my best helpers and can rightly be called the "bible of wine knowledge".
Prof. Dr. Walter Kutscher
Lehrgangsleiter Sommelierausbildung WIFI-Wien