Why is red wine red, and how do white, rosé and orange wine differ?

Red wine is red because the grape skins stay in the vat. Red wine is made from red or black grapes, and the fermentation takes place together with the skins, which give the wine its colour, flavour and tannins through a process called maceration. For nearly all red wines the colour comes from the skins, so contact between the juice and the skins is essential.

White wine is the opposite recipe. It is made by pressing crushed grapes and fermenting only the juice, and the skins are removed. That is why red grapes can make white wine: if they are pressed quickly, and the juice is kept away from the skins, the wine stays pale. Blanc de noirs sparkling wine is exactly that, a white wine from Pinot noir, a red grape.

Rosé sits in between. It is usually made from red grapes whose juice stays on the dark skins just long enough to pick up a pink colour, and less commonly by blending red and white wine. White and rosé wines take little of the tannins that the skins contain.

Then there is orange wine, which flips the idea around. It is skin-contact white wine: white grapes made with maceration, in the manner of rosé or red wine. The skins carry pigment, phenols and tannins that are normally unwanted in white wine, and here they are kept on purpose.

So one dial, time on the skins, explains much of the rainbow in the glass. Short gives white, a little more gives pink, and a long contact gives red, or amber when the grapes were white.