Clarification and filtration of wine
Winemaking is a long process. It takes a variety of techniques to produce fine wine from grape picking and bottling. Clarification is a very important step in the process of winemaking. Many wineries will clarify the wine to a certain extent before bottling.
What is clarification? Why clarify? What are the common clarification methods? The following will reveal for you.
1、 Definition of clarification
Clarification is a process to purify and stabilize the wine by removing sediment from wine through precipitation, gelatinization, and filtration. Most wines need to be clarified before bottling in order to remove the substances causing wine turbidity and improve the stability of wine.
Some winemakers think that this process will damage the characteristics of wine, so some wineries only carry out minimal clarification or even no clarification before bottling. Unfiltered or unfiltered wines are sometimes labeled as unfixed or unfiltered, which is less clear than clarified wines.
2、 Main clarification methods
The principle of the precipitation method is to let the suspended particles in wine settle to the bottom of the wine under the action of gravity. After the suspended particles settle to the bottom, the wine can be gently transferred to another container, leaving only the sediment. However, due to the weak gravity effect of suspended particles, this method generally takes a long time.
Filtration is the process of removing particles by a physical method when liquor passes through the filter. This method is easy to remove wine mud quickly, usually before bottling to ensure the clarity of the wine.
There are two main methods of filtration
Depth Filtration —— The filter used for deep filtration usually has a thick membrane, which can remove the coarse wine mud. It is suitable for turbid wine.
Surface Filtration —— The wedge wire filter used for surface filtration is similar to a very fine sieve. The size of its pores can be selected by oneself. The larger pores can filter out solid particles, and the smaller pores can remove yeast and bacteria in liquor. However, this kind of filter is expensive and easy to block. It is usually used for wine that has been deeply filtered.
Gluing is to add substances with adsorption capacity to the wine, condense the substances causing wine turbidity into particles or agglomerates, and finally remove them through filtration. Winemakers generally use the method of gelatinization to clarify the wine and choose the appropriate clarifier according to the characteristics and state of the wine.
3、 Factors affecting wine clarification
When clarifying wine or grape juice, the temperature is one of the most important factors. Most clarifiers have obvious effect only when the temperature exceeds 15 ° C, and the best temperature is 20 ° C.
The time of precipitation will also affect the effect of clarification. If the purpose of clarification is to improve the clarity of the wine, then time is a crucial factor in the whole process. If the clarification is finished too early, there will be residual suspended particles in the wine, which will make the wine still look turbid.