adding sugar in different form to fresh grapes. grape, partially fermented grape must, young wine (not finished fermented) 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 of a wine (in which an increase of the residual sugar takes place) or the Spriten To do (alcohol addition to the already finished wine). The goal is to make the natural by fermentation of the additional sugar alcohol content in the wine increase.