False colour scanning electron micrograph of wine yeast cells Saccharomyces cerevisiae (var. ellipsoideus), (tiny balls) on crystals of potassium hydrogen tartrate precipitated out from red wine & growing on the inner surface of the cork. The flavour of a wine depends on the variety of grape used, the soil, the weather etc. & the type of yeast found growing in association with the fruit. The yeast ferments the wine to a good alcohol level. In some winemaking processes the grapes are sterilized & the yeast added, but in the better quality wines the original or wild yeast (i. e. naturally occurring on the fruit) is used. Magnification: X940 (6x7cm). Original is bw print b250/279.