The colour of a wine can tell you much about it, but sometimes all is not what it seems.
Decades ago it was quite normal for a Burgundy producer to add a good slug of wine from a warmer part of the world to make up for any deficiency in their product. In theory this shouldn’t happen any more, and better vineyard practices and winemaking skills have improved the wines. There are rumours of this sort of practice still happening in some regions; and in some parts of the world the geographic boundaries are so large that blending is normal practice.
What gives a wine its colour?
The colour comes mainly from the grape skins. A classic example of this is the Pinot Noir grape variety. It normally makes red wine, but the pulp in the centre of the grape is white, so, if you gently press the grapes, and ferment the juice you get a white wine, as in Blanc de Noir Champagnes.
I’ll exclude fortified wines.
- White – wine made by pressing grapes, and fermenting the juice without skin contact.
- Orange – wine made from white grapes, but where the skin is in contact with the juice during fermentation. This was very unusual, but is becoming more popular.
- Rosé – wine made from red grapes, where the grape skins are left in contact with the juice for a short period to impart some colour.
- Red – where the grape skins are left in contact with the juice throughout fermentation. The colour can vary from a pale garnet to an inky impenetrable purple.
Which other factors influence the colour?
- Acidity. Usually expressed as the pH. The acidity decreases as a wine ages.
- Sulphites. These are added as an anti-oxidation and to kill off bacteria, but they also change the colour of a wine.
- Ageing. The chemical reactions in a wine cause white wines to become darker in colour as they age, and red wines to become paler. They all tend towards brown in the end.
- Oak barrels. Some air reaches the wine whilst it is an oak barrel, and this can affect the colour, as can some chemicals leached from the oak.
Wine additives which influence colour
- In addition, or instead of, blending wine from outside the region, some winemakers will add food colouring. The most honest of these are at least grape-derived, an example being ‘Mega Purple’. They are concentrates where a little goes a long way, and some change the taste as well as the colour.
- It is also possible to remove colour by using activated charcoal.
There are two ways of looking at the manipulation of wine:-
- The wine reflects the area that it comes from, often referred to as terroir, and also the winemaker’s skill. The addition of wine from outside the area, or wine concentrate, masks the individuality of the wine and so detracts from it.
- The winemaker aims to produce a consistent product every year, and that additives which achieve that are entirely justified. Cynics might suggest that they simply make up for poor winemaking. It should be said that the blending techniques used in Champagne to achieve a standard non-vintage wine are an honest way to achieve a consistent product.