Wine draining
Draining separates the liquid phase of the must from its solid phase, the marc, by draining the free-run wine from the bottom of the vat. Carried out in order to vinify red wine, this operation puts an end to maceration, and therefore to the diffusion of tannins and pigments in the future wine.
What is the difference between draining and devatting?
When the winemaker has reached the desired level of extraction of tannins and colouring matters from the must, it is time to end the maceration process. The wine is then run off at the end of the vatting process. It is not always carried out at the same time as the end of alcoholic fermentation. If the amount of sugar is still high or the alcohol content insufficient, it can be finished later.
When the must is drained, its solid parts float to the surface: this is called the cap, or marc cake. To isolate it, the winemaker opens a tap at the bottom of the vat. The liquid part of the must flows by gravity and the liquid leaving the valve is called "free-run wine". This oenological nickname is due to the fact that this wine is made by draining!
To finish emptying the vat, it's time for devatting, which consists of transferring the cake of marc to the press to extract the liquid from which it is soaked. In other words, press wine! Running off and devatting are not to be confused with racking. This clarification method involves decanting the must to purify it of its deposits, the lees.
Free run wine, press wine: what are the differences?
Because free-run wine comes from the liquid phase of the must, it is naturally more fragrant, lighter and less tannic than press wine. Smooth, this young wine is appreciated for its roundness, although it is sometimes acidic.
The press wine, which comes from the pomace, has a high concentration of pigments and tannins, and its intensity depends on the number of glasshouses used to press it. The volume of this full-bodied liquid is 12 to 18% of that of the free-run wine.
These two wines can then be blended together to balance and rectify the organoleptic profile of the free-run wine, if necessary. The quantity of press wine reintroduced before continuing fermentation will therefore vary according to the quality of the cuvee and the product desired by the winemaker.
Is this for red, rosé or white wines?
Draining is by definition a specific stage in red winemaking. It involves separating the solid and liquid phases of the must, and implies that maceration has taken place beforehand. The draining process therefore applies to the same wines as the latter, i.e. :
- red wines, made from red grapes,
- bleeding rosé wines, made from the short, pre-fermentation maceration of a red grape harvest,
- orange wines , white maceration wines produced by vinifying a white grape variety as if it were a red grape variety