🍷 Racking

Racking is moving wine from one vessel to another so that the solid deposits stay at the bottom. It takes the wine off its yeast lees after fermentation and later off the deposit left by clarification or chilling. Without it the wine would lie for a long time on dead yeast and sediment.

The OIV names four aims of racking: to separate wine from its lees and from the remains of fining agents; to separate it from microorganisms at the end of alcoholic or malolactic fermentation; to allow other operations — treatment, blending or transport; and to complete tartrate stabilisation by chilling, removing the tartrate crystals.

Racking can be done in different ways. Without contact with air — to prevent oxidation; the receiving vessel is then filled beforehand with carbon dioxide, nitrogen or argon. With aeration — to remove hydrogen sulphide, reduce carbon dioxide or give the wine controlled oxidation. Wine is moved with pumps, connected vessels or by hand, at room temperature or after chilling so as not to lose carbon dioxide.

In the EU an inert atmosphere may be created only to handle wine shielded from the air, and argon, nitrogen and carbon dioxide are among the authorised gases. Racking often prepares wine for filtration or centrifugation, that is, for physical clarification.

Why it matters to you. Racking without air keeps the wine's fruity freshness, while racking with aeration helps get rid of a rotten-egg smell — hydrogen sulphide. How carefully it is done decides whether oxidised notes appear in the wine.