Since “black grapes” are often reddish & “white grapes” quite yellowish/greenish, is red wine really red and white wine really white?
Masterclass at the Aviva Stadium, Dublin, February 2017
The first thing that struck me at my first wine tastings was the range of adjectives & nouns people could use to describe how red a red wine was or wasn’t (ruby, garnet, purple, tawny, mahogany…), and that’s not even getting into the rim variation along the glass! So, what is it that gives wine its colour and why is everybody paying so much attention to it (or money for it?)?
What Makes Red Wine Red?
In our Grape Tasting tutorial, we found out that pigments (colouring agents) that make red wine red are located in the skins of the grapes. You only have to peel off some black grapes to show that the pulp is colourless. In these skins, some small compounds make up the colour of our red wines, two of them being responsible for the final hue:
Anthocyanins: They are polyphenols, the “good stuff” you also find in olive oils and that makes you cough when it is very fresh and of good quality. We know that polyphenols bring good things to our bodies (in the case of wine, if enjoyed responsibly, of course…), their main effect being a good antioxidant. Their colour is dark red/blue to purple.
Purple deposit on a natural cork (5 year old Bordeaux)
What the Colour is Telling You
If you are a seasoned wine drinker, you might have had the opportunity to crack a couple of older bottles of red wine at some stage. The first thing you notice when you pour it into the decanter or straight into the glasses is its quite light concentration (more translucent than opaque, right?..).
Red wines tend to get paler and paler as they age, while white wines tend to go darker and darker. Theoretically, somewhere down the line, a white that’s old enough will show a similar colour to a red that’s as old…but that’s not the point: the colour is usually a good indication of age. How come?
Anthocyanins (the purple stuff) have a tendency to bind with other compounds in the wine, making them heavier as they do so. At some stage, being too heavy to stay in suspension, they eventually precipitate to the bottom of the glass, forming the dark purple sediments you might have found at the bottom of an older bottle of wine.
However, tannins (the orange stuff) don’t precipitate, and that’s why a very old red wine will in fact display an orangey/tawny colour. The best example of that being old Nebbiolo (Barolo, Barbaresco…) or even old Brunello di Montalcino (made of Brunello grapes, a clone of Sangiovese).
Knowing that, you can guess the following things from looking at the colour of a red wine:
Light Orangey/Brownish Rim Variation: The wine is showing an early sign of ageing, it is probably 2 to 4 years old, depending on the width of the rim. The browner the rim, the more of an indication of a potential “oak ageing”.
Tawny/Orangey Core: These are your very old wines, usually from 10+ years, most of the anthocyanins have dropped. For these, I would definitely recommend a decanter, as a fine layer of sediments is to be expected.
When it comes to white wines, it is slightly harder to find generic terms since the influence of the climate, oak ageing and soil types in the vineyard will also greatly influence the colour of the wine. Thanks for reading!
Certified Sommelier (CMS)