What is the process of clarification? Clarification process
Pressed grape juice is always a bit cloudy. It will contain some solids and soil, which will give the wine a bad taste and should be removed. To do this, we can inject the grape pulp into a centrifuge unit, which is fast and effective, but some winemakers accuse this method of making the wine tasteless and barren. People mainly use this method to make large quantities of wine or grape meal.
Another method is cryostabilization: storing the grape pulp at a low temperature (near 0°C) and waiting for impurities to precipitate. This method has many advantages: the pulp is protected from the fermentation process and the impurities settle naturally to the bottom of the wine tank.
Sulfur addition for freshness
Regardless of the method used to clarify the grape pulp, it is necessary to go through the process of adding sulfur. In other words, one should add sulfur dioxide (SO2) to the slurry to prevent oxidation and microbial derivation. The amount depends on the hygienic and health conditions of the must and the ambient temperature. Excessive use of SO2 will completely overwhelm all the aromas of the wine. Its dosage is strictly regulated every year.
In France, many consumer associations and winegrowers advocate the labeling of wines with substances other than natural grape grains. However, by law, only the use of sulfur dioxide in wine must be indicated on the wine label. Excessive doses can cause headaches and side effects for some consumers.
Different Pressing Devices
There are various grape seed crushing devices with capacities ranging from several hundred kilograms to several tons. Modern presses are fully automatic and the most common type is the horizontal press. Among them, pneumatic pressing is the softest method, which contains air bladders. The volume of the air bladder is increased to squeeze the grape seeds. However, some winemakers still prefer the traditional vertical conventional press: the moderate pressure is concentrated over a wide surface area and the wine is clearer after pressing, which is not difficult to clarify.
Alcoholic fermentation
The must is then poured into wine tanks, where it undergoes a slow fermentation process lasting two to four weeks. The fermentation process can be initiated by adding artificial yeast or by introducing yeast by adding additional slurry to the other wine tanks where the fermentation is taking place. Temperature is an important factor in determining the degree of fermentation and the style of wine.
The lower the temperature, the longer the fermentation time, the better the extraction of substances from the grape seeds, and the higher the quality of the final wine. The higher the temperature, the shorter the duration of the fermentation process, the lower the quality of the wine, the less flavorful it is, and the less jammy the ripe grapes are.
