Sugars in wine as chaptalization solely in order to boost the alcohol content – chaptalization does not increase the "sweetness" of a wine. Glucose, along with fructose, is one of the primary sugars found in wine grapes. In wine, glucose tastes less sweet than fructose. It is a six-carbon sugar molecule derived from the breakdown of sucrose. At the beginning of the ripening stage there is usually more glucose than fructose present in the grape (as much as five times more) but the rapid development of fructose shifts the ratio to where at harvest there are generally equal amounts. Grapes that are over
Wine Grapes and original work that is much more extensive in coverage, and also incorporates recent findings from ampelographic research, including DNA profiling of grape varieties. "Wine Grapes" include a catalog listing of 1,368 grape varieties from across the globe including 377 Italian, 204 French and 77 Portuguese wine grape varieties. Coverage includes a listing of synonyms as well as the genetic relationship between varieties derived from DNA analysis. According to Jancis Robinson and José Vouillamoz, "Wine Grapes" includes details about almost 300 previously unpublished relationship between different grape varieties including the extensive family tree of the Pinot grape that includes a