The Weinhof Krachler vineyard in Austria has seven hectares of land devoted to viticulture. It produces a range of wines, including red, white, rose and sparkling wines.
The process of wine making at the vineyard begins with producing wine must.
The grapes are first harvested, weighed, and processed to squeeze out the juice. This ‘wine must’ is essentially grape juice that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes between 7 and 23 percent of the total weight of the must.
At this stage, the must has a particular sugar content that the wine maker needs to know to control the fermentation process more precisely. This is important because the quality of the wine is dictated by its sweetness and potential alcoholic content. The solution provided by ABB helps to ensure the right balance of sweetness and acidity in the finished product.
Markus Krachler, owner of the Weinhof Krachler vineyard, says: “The sweetness of the juice is important to know as it gives information on how much alcohol will be in the final wine after fermentation. Not all the sugar is fermented during the winemaking, as some is left to give the wine a proper sweetness.”
The acidity is also measured, and together with the measurement of sweetness, this allows the quality of the finished wine to be determined. Depending on the type of wine and grape, different rest sweetness is required in combination with the acidity. For example, some wines, such as dessert wines, contain more sugar while having less acidity.
Grape sweetness has traditionally been measured by taking a sample and assessing it using a refractometer. This measures the refractive index of a liquid, which changes according to moisture content.
However, using a sampling method that allowed only intermittent measurements provided limited information. Krachler wanted a more comprehensive measurement system that produced more data and so chose the ABB CoriolisMaster FCB450 and the RVG200 data recorder.
“Introducing continuous on-line measurement provides a constant indication of sweetness. By using the CoriolisMaster, we get not only the sweetness but also the weight of the produced juice and the volume as well.”