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Coloured Wine

How red is it anyway?

How red is it anyway?

The colour of a wine can tell you much about it, but sometimes all is not what it seems.

Blending wines
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.

Wine colours
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.

Conclusion
There are two ways of looking at the manipulation of wine:-

  1. 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.
  2. 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.

Is there a perfect temperature for storing wine?

temperature and humidity recorder

temperature and humidity recorder

Wine is an organic living thing. The temperature a wine experiences can have a big influence on its quality.

So, is there a perfect temperature?
Time has shown that deep cellars in temperature parts of Europe are perfect for wine storage. A constant temperature of around 12°C (54°F) is ideal. A high humidity prevents the cork from drying out.

Increased temperature leads to increased reaction rates
Wine is a complicated mixture of chemicals, which react with each other. As the temperature rises, all of the reaction rates will increase, but some will increase more rapidly than others.

Increased temperature leads to new reaction products
As the temperature rises, new reactions will occur, which simply wouldn’t happen at 12°C. An example is the breakdown of aromatic chemicals in dry white wines. Unpleasant compounds are also produced.

Wines with low sulphites/sulphur dioxide
Natural wines with low levels of sulphites (sulphur dioxide) are increasingly popular. Sulphur dioxide serves two very useful functions:-

  • to limit oxidation of the wine.
  • prevent bacterial growth.

Both of these become much more of an issue as a wine’s temperature rises, and natural wines are particularly vulnerable.

Unfiltered wines
If the temperature gets too high, it is perfectly possible to restart fermentation . This causes plenty of problems.

What if the temperature is lower than 12°C (54°F)?
As the temperature decreases, the reaction rates slow down. So, a wine may not mature in the normal way, but at least it won’t go off. If a wine gets cold enough it may deposit white tartrate crystals, but these do no harm. The alcohol in wine depresses its freezing point, so it needs to be well below 0°C (32°F) before it even starts to freeze.

Conclusion
If you live in a climate where the temperature is above 25°C (77°F), and you don’t have dedicated wine storage, then please keep ALL your wine in a domestic fridge. You will have to remember to take the red out in good time before drinking it, but at least the wine will be in good condition.