The making of red wine differs fundamentally from the production of white wine. The difference lies not only in the choice of variety in the vineyard but also begins with foliage management and in the qualitative grape reduction in the summer. As there is no risk of sunburn in red wine grapes, a greater defoliation of the grape zone is ensured.
One way of increasing the quality, is halving the grapes in the summer, in particular the grape variety Zweigelt. As a result, the remaining berries are better supplied with sunlight and the grape cluster stretches. This prevents botrytis and makes it possible to wait for the harvest even in rainy weather conditions.
The grapes are harvested by hand and put into grape boxes of about 400 kilograms. Higher outdoor temperatures during harvesting are not a problem as, contrary to white wine, higher tannin contents do not impair the quality of the wine.
The boxes are emptied into the destemmer by forklift. This machine allows the separation of the berries from the stem. This excludes the green tannins of the stalk from further processing. Depending on the variety and type of wine, the berries are then crushed or remain as whole berries. The mash is now pumped gently and put into the fermentation tank.
In recent years, closed fermentation has become increasingly prevalent in Austria and Germany. The mash is fermented in steel tanks or oak barrels with open top. At the beginning, the water in the double bottom can be heated by means of heating rods, thus the fermentation can be started more quickly. On the outside of the tank cooling surfaces are arranged to control the desired fermentation temperature.
The more fermentation happens, the more sugar is converted into alcohol and CO2. Due to the rising CO2 the mash takes on the texture of a cake and begins to move to the top where it floats. As it would dry out there, the mash is mixed either mechanically or pneumatically with the juice or pumped by remontage of the juice from above the mash. This results in a more homogeneous fermentation and good leaching of all berries.
After the fermentation has ended, the juice is drained directly through a sieve and then usually comes into a barrel for malolactic fermentation. The remaining berries are then filled into a box, and tilted onto the press where they are pressed. The remaining pomace subsequently processed into compost.