Racking is part of the production process in wine, but maybe isn’t what you think it is.
The word racking itself originated from the Old English term ‘rakken’, which means skins, pips and stalks of the grape.
Once the juicy grapes are ripe for the picking, they are harvested and placed in a large press or barrel. They are either destemmed and crushed (white wines), or just crushed (red wines, though it depends on the grape variety). At this point, the grapes are left to ferment with yeast, along with other additives. The skins and pips are left in red wines, while the white-wine grapes are separated from the skins. The wine at this stage is cloudy and opaque.
The yeast consumes the naturally occurring sugars, creating CO2 and alcohol. Fermentation is almost over when the carbon dioxide bubbles have stopped floating to the top of the tank—this is the first natural clarification because of gravity. The dead yeast cells and general ‘rakken’ drop to the bottom of the vessel or barrel. If this mass isn’t removed, it will naturally begin to decompose, which will give the wine a bitter taste, called ‘yeast bitten’.
Disclaimer: the wine-making process is a lot more seductive and detailed than this explanation allows, but for the sake of a Small Sip, we’re keeping it simple.
As soon as the wine begins to clarify (which can take up to two days), it is carefully drawn off, leaving the sludge deposit behind. This is the process known as racking. Some winemakers choose to leave some of the remnants in the wine, as they add to the ‘natural effect’ and are harmless.
Image by Silver Oak Cellars – Image provided by request from Silver Oak Cellars., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=26393090