adding sugar in different form to fresh grapes. grape, partially fermented grape must, young wine (not finished fermented yet) and Wine, The terms alcohol increase, improve, chaptalisation or grape picking up. An amount of 17 to 19 grams of sugar per liter of wine increases the alcohol content by about 1% vol. The process has nothing to do with the sweetening a wine (in which an increase in the residual sugar takes place) or the Spriten (Alcohol addition to already finished wine) to do. The aim is to make the natural sugar by fermenting the extra sugar alcohol content in the wine increase.