A look at a wine analysis machine and some other technical info
Day 13: September 14, 2023
Vineyard: Cantine Amastuola, Massafra, Puglia
Teo takes us through a quick overview of a wine analysis machine and the parameters that are obtained for analysis.
We tasted more samples from tanks, mainly Sauvignon Blanc. Since this winery only produces organic wines, stabilizing the wine has to be achieved in natural ways, that is, without additives. Hence, the stabilization is achieved by freezing the wine to -40 Celsius. The freezing reduces the acidity of the wine, so it is important to maintain a high level of acidity in the fermentation tank.
Checkout the photos below where yeast is added to the tanks from buckets.
The effects of Adding Sulphur
You add Sulphur to primarily stop the fermentation process, both alcoholic and malolactic. It essentially kills the yeast (alcoholic fermentation) as well as the bacteria (malolactic fermentation). Sulfur Dioxide (SO2) is what is used for this purpose. However, when SO2 is introduced into the tank, the SO2 interacts with the oxygen in the tank to produce Sulfur Trioxide (SO3). Since the oxygen in the tank is consumed during this transformation, it can have a detrimental effect on the vinification of the wine in the tank. The process of controlling how much Sulphur is added is a very important aspect of wine making when the wine is being stabilized.
An Explanation of Alcoholic and Malolactic Fermentation
After the alcoholic fermentation is complete, the malolactic fermentation begins. The latter is a much slower process. Typically if there is gap between when the alcoholic fermentation ends and when the malolactic fermentation begins, the bacteria could create acetic acid. This is generally not good for the wine, since it gives the wine a bad smell. This is where Sulfur comes into play, to kill the bacteria. In the organic wine making process, you want to minimize the gap between the two types of fermentations, ideally starting both types at the same time. As you add yeast for the alcoholic fermentation, you also add bacteria in very controlled quantities. The bacteria will initiate the malolactic fermentation simultaneously. However, you have to be very careful. If there is too much bacteria, then the bacteria consumes the sugar in the must and produces acetic acid, giving the wine an undesirable smell. The winemaker orchestrates this balancing act.
