This measure in the vineyard primarily serves to increase the quality of healthy grapes and as a side effect also to reduce the yield, It is particularly recommended for a dense and compact grape structure, which is the cause of bunch rot (Acid rot). With dense berries grapes the inside is poorly ventilated, so after rainfall (Rain, dew) drying is too slow and the moisture provides ideal conditions for putrefaction. In addition, the high pressure in the middle part causes the berries to be squeezed and thus the prerequisite for the penetration of bacteria and mushrooms, Rotting berries lead to flavors wine errors, Grape varieties with compact opposite lockerbeerigem Berry growth is particularly at risk, including those Pinotsorten. Sauvignon Blanc. Elbling and Riesling, Various measures for loosening grapes have therefore been developed. These include the Defoliation the grape zone, as well as the grapes division and the grape break.
Grape breaking does not take place like with the classic yield reduction thin out (Green harvest) to promote grape compactness, but does just the opposite. And it has the advantage of less effort compared to the similarly effective grape division. The measure to be carried out manually takes place between closing of grapes and veraison (Maturity onset). Only the compact grapes are treated. The grape is fixed in the upper and lower area with one hand each and the two halves twisted against each other. Above the compression zone there is a clearly audible breakage of the stem structure; there is a predetermined breaking point, so to speak. The upper, looser grape part remains on the stick, the lower, more compact part is separated. As a result, berries move down from the upper half, which further reduces the berry contacts. Certain grape varieties such as B. Riesling are particularly suitable with regard to grape structure (pictures above).