Supermarkets are arranging wine tasting sessions around "good" and "bad" days as dictated by the lunar calendar. So does the Moon really change the taste of wine? A German great-grandmother called Maria Thun is wielding huge influence on the British wine industry. A calendar she first published in the 1950s categorises days as "fruit", "flower", "leaf" or "root", according to the Moon and stars. Wine is best on fruit days, followed by flower, leaf and root days. The worst day is marked as "unfavourable" in the calendar. (See factbox below for forthcoming "good" and "bad" days).