Category Archives: Oak

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.

Rioja

The wines of Rioja are a particular favourite of mine. The best wines show what the Tempranillo grape variety can achieve. Some wines are made to drink soon after they are made, and others just last for decades.

Rioja vineyards

Vineyards and mountains of Rioja

Geology
The Rioja region has a beautiful setting in central northern Spain. It is sheltered from the north, south and west by mountain ranges. The river Ebro, which is at the heart of Rioja, drains East into the Mediterranean, rather than the Atlantic which is much closer.

  • Soils near the river are alluvial deposits of sand, gravel and limestone.
  • Elsewhere, soils are a mixture of iron-rich clay, limestone and sandstone.
  • Geological activity over the years has turned this into a complex mix of soils, which can vary over short distances.

Climate
The mountains surrounding the Rioja region protect it from weather extremes. But it is influenced by three weather regimes.

  • Atlantic – mainly cool and wet.
  • Continental – searing hot in the Summer, and very cold in the Winter.
  • Mediterranean – a warmer influence from the East.

During the growing season, the weather is often hot and dry during the day, and much cooler at night. Ideal for growing grapes.

Rioja Wine Regions
There are three designated regions:-

  • Rioja Alta and Alavese to the West. The vineyards are at higher altitude and cooler than those to the East. The climate and soil are particularly suitable for high quality Tempranillo grapes.
  • Rioja Baja to the East. It is warmer and drier than it is to the West, and the conditions suit the Garnacha grape variety.

Wine classification
Rioja was the first wine region in Spain to be awarded DOCa status, the highest level in Spain. Within this there are four classifications based on the amount of barrel and bottle age that a wine has been given. However, this is only part of the story, as there can be a large variation in quality and price between wines within a given category.

  • Joven, or ‘young’ wines. These have no wood ageing, and are not for keeping.
  • Crianza – not released before their third year, with a minimum of 1 year in oak barrels.
  • Reserva – minimum of three years total ageing, of which at least 1 year is in barrel.
  • Gran Reserva – minimum of 2 years in barrel, and 3 years in bottle. Most producers will only make these wines in top years, when prime quality grapes are grown.

There are slightly different rules for white wine, but very few bodegas make wood-aged white Rioja any more.

New styles of wine
Red – some producers are trying to differentiate themselves from the rest by not using the above designations. They make a more powerful style of wine.
White – the old style of oaked white wines is a minority interest, even though the best are excellent. The new style is crisp and dry, and fairly aromatic. Made for the international market.

Conclusion
Rioja makes many really good wines, and apart from a few cult wines represents excellent value for money.

Wine and food matching

Matching wine and food is not an exact science, and everyone’s taste is different. It is a value judgement. But there are some basic guidelines which help to avoid unpleasant clashes.

artichokes

artichokes – a challenge to match with wine

Acidity
The more acidic a wine, the easier it is to match with foods. Think of how a dash of lemon juice enhances some dishes.

  • Acidic wines deal very well with salty foods such as oysters, or oily fish like mackerel.
  • The wine should be more acidic than the food. In fact food can temper a wine which would otherwise be too acidic for most.

Alcohol
Alcohol in wine affects the texture in the mouth, and if it is too high causes a bitterness and burning at the back of the throat.

  • Match the weight of the wine with that of the dish. Most foods are fairly light-weight, so it is easier to match lower alcohol, more elegant wines.
  • Avoid drinking high alcohol wines with chilli or very salty dishes – it just reinforces the burning.

Tannin
Tannins come mainly from the skin and pips in grapes, so are most often found in red wines. They react with the saliva in your mouth to cause a puckering sensation. Tannin levels decrease as a wine ages, so young wines are more tannic than older ones.

  • Tannic wines clash badly with many fish dishes, leaving a metallic taste in the mouth.
  • Tannic wines go very well with fat and protein – grilled steak for example.

Oaked wines
Both red and white wines can be oaked, but it is much more common in reds. Oak treatment is expensive, so it is done with better wines. The resulting wine has more body and tannin than lighter-styled wines.

  • Avoid delicate dishes, as the wine will overwhelm it.
  • Pick dishes with rich sauces, or where the food has been grilled rather than poached.

Sweet wines
Are those with residual sugar. Note that they should also have a balancing acidity, or else they are just cloying and will hardly match any food at all.

  • The sweet wine should be sweeter than the pudding you are eating.
  • Semi-sweet wines go well with spicy hot food.

Conclusion
There is no point drinking a wine which you don’t like, just because someone on TV has declared it a perfect match with the food you are eating. In the end, you should drink what you enjoy, but perhaps use the above guidelines to avoid the worst clashes. If a wine really does clash, you can always finish it off after you’ve finished the food.

What is meant by a corked bottle of wine?

selection of natural corks

Bleached and unbleached natural corks

A ‘corked’ wine has a mouldy taste and smell. This is caused by chemicals leached from the cork, and is nothing to do with bits of cork floating in the wine.

Where does natural cork come from?

Natural cork is made from the bark of the Quercus suber oak tree, and Portugal is by far the largest producer. The bark is stripped from the tree, and this particular species is able to regrow its bark. Individual corks are then punched out from the bark. Various treatments are carried out along the way.

Origin of cork taint

The main culprit is a chemical called TCA, 2,4,6-trichloroanisole to be precise, although other similar compounds are also responsible. There are several possible sources of these compounds, and they involve fungi, microbes and chlorine treatments, either of the cork oaks, or the punched corks themselves.

How bad is the problem?

There was a time when the percentage of ‘corked’ bottles was estimated at between 2 and 6%. I would say that the incidence has decreased, but the problem has not been eradicated.

What are the cork producers doing about it?

There are two general approaches:-

  • Change the sterilising treatment – in the past hypochlorite bleaches were used to kill off microbes in the cork. Now they use peroxides, or microwave treatments to remove unwanted life in the corks.
  • Use of high tech analytical equipment, such as mass spectrometers and gas chromatographs. These can detect extremely low levels of contamination.

What are winemakers doing about it?

Apart from changing away from natural cork, the best a winemaker can do is to buy top quality corks. Samples from a batch can be tested by immersing them in wine, to see if there is any contamination.

Threshold levels of taste and smell

The threshold level is the minimum concentration at which a person can detect a smell or taste. TCA can be detected at incredibly low levels of a few parts per trillion (yes, a million-millionth). There are two interesting observations:-

  • Some people are far more sensitive to cork taint than others – they have a much lower threshold level. So that one person thinks a wine is just fine, and another that it is undrinkable.
  • The threshold level increases rapidly as the alcohol content increases. Which is why cork taint is very rare with bottles of spirit.

Can cork taint be completely removed by changing to screwcaps or plastic corks?

The answer is no, but the incidence will be much lower. TCA can contaminate other wooden objects in a winery, particularly oak barrels. So some contamination is always possible.

Why use Wood in Wine Production?

wine barrels

Wine barrels in a Burgundy cellar

Fermenting and maturing a well-made wine in oak barrels softens the wine, and makes it more complex.

Four things happen when a wine sits in an oak barrel:-

  • Chemicals are leached out of the wood, which provides the distinctive vanilla taste, amongst others.
  • Small amounts of air pass through the barrels, which influences the way the wine matures.
  • Some wine is absorbed into the barrel, and some alcohol evaporates. So the wine in the barrel needs to be topped up.
  • The wine is gently clarified.

Types of oak and their treatment
Several different types of oak are used, and each gives a different taste. The oak is split into strips, known as ‘staves’, and allowed to dry outside. This seasoning removes the harsher tannins in the wood. The barrels can be further treated by burning the inside, a process known as toasting, which also reduces the flavour and tannins which are imparted to the wine. This video by Jordan Winery tells you all you need to know.

New barrels vs old
Old barrels, which have been used before, will impart less taste than new barrels, as most of the chemicals have already been leached out.

Large barrels vs small
Large barrels impart less taste than small ones, because the flavour is diluted over a larger volume. Also, the air that penetrates the barrels is spread more thinly in large barrels, which leads to slower ageing.

Oak chips
Some winemakers put oak chips into their wine while it is maturing, to give it ‘oak character’. This is obviously cheaper than using oak barrels, and is used on cheaper wine, sometimes with unfortunate results.

Where it can go wrong
The use of oak in winemaking is a complicated business, and a great deal of skill is required in dealing with it. Several factors are listed above, but there are more besides. Most importantly, the wine needs to be tasted during its evolution. Not all wines improve with exposure to oak, and it is easily overdone.