Category Archives: Taste

Sugar in Wine

Sugar plays a vital role in the wine in your glass, even if you can’t taste it directly.

ripe grapes

Ripe grapes

What is sugar?
Sugar is the name given to a wide range of carbohydrates, but only the simpler ones are sweet.

  • Glucose – one of the main products of photosynthesis in a plant, making up about 50% of sugars in ripe grapes. It is one of the three simplest types of sugar, known as monosaccharides. This is absorbed straight into the bloodstream during digestion.
  • Fructose – another monosaccharide, making up the other 50% of sugars in ripe grapes. It too is absorbed straight into the bloodstream during digestion.
  • Sucrose – the type of sugar you put in your tea, is typically produced from sugar cane or sugar beet, and very little is found in ripe wine grapes. Sucrose is in fact a combination of glucose and fructose.

Production of sugar in wine grapes
There is very little sugar in a grape until véraison, when the grape starts to change colour and ripen. Acidity decreases, and sugar contents rise, see the graph in a previous post. The trick is to get the correct balance between the two. Sugar concentrations in ripe grapes can easily achieve 20%.

Adding sugar manually

  • Before fermentation – sugar in grapes is converted to alcohol during fermentation, but if the grapes aren’t ripe enough, sugar may be added to artificially increase the alcohol content. A process known as chaptalisation. If this is done carelessly, there isn’t enough fruit in the wine to balance the relatively high alcohol. This practice is banned in many wine regions.
  • Adding two lots of sugar – Champagne manufacture involves adding sugar and yeast to produce bubbles in the bottle, and then sugar at the end to take the edge off the acidity.

Fermentation
Yeasts turn the simpler sugars into alcohol plus carbon dioxide, but many other reactions also happen, and some of the complex sugars remain.

Effect of residual sugar in wine

  • Tasting thresholdfor most people this is around 1% sugar content, but those who are particularly sensitive can detect 0.2%. A dry wine which is fully fermented out will have a sugar content of < 1.5 gm/litre, which is not detectable.
  • Balancing other tastessweetness balances acid and bitter tastes, making them less harsh.
  • Provides food for microbesresidual sugar in wine encourages bacterial growth unless it is properly protected. Sulphur dioxide is important here, see previous post.

Conclusion
In most wines, sugar just has a fleeting presence for a short while before the grapes are picked. It is created by photosynthesis, and consumed by fermentation.

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.

Wines to drink with blue cheese

 

unpasteurised blue cheese

unpasteurised blue cheese

Blue cheeses provide the biggest challenge when matching with wine. They can be sweet, salty and spicy. These attributes clash with the tannins in red wines, producing a metallic taste. The solution is sweet wine.

Methods for making sweet wines
Quality sweet wines are made by dehydrating grapes, which concentrates the sugar. If this is high enough, then some remains after fermentation. Examples of how these are made:-

  • A fungus called botrytis cinerea, also known as ‘noble rot’, can infect individual grapes under the right conditions. The infected grapes look revolting, but taste delicious.
  • ‘Ice wine’ where grapes are left on the vine until the weather gets cold enough to freeze them. If they are pressed in this state, the juice is very concentrated.
  • Grapes are allowed to dry on the vine, or after picking, to become raisin-like.

Examples of these types of wine are:-

  • Sauternes/Barsac from the Bordeaux region. Also look for Loupiac and Monbazillac, less expensive and from the same grape varieties and region.
  • Sweet Chenin Blanc wines from the LoireCoteaux de Layon, and Quarts de Chaume. Vouvray is made in many styles, and the sweet versions are labelled Moelleux or Liquoreux.
  • Sweet Alsace wines, particularly Selection de Grains Noble.
  • Tokaji from Hungary. The more Puttonyos declared on the label, the sweeter the wine.
  • Sweet Muscats, made in many countries.

Adding alcohol to stop the fermentation:-

Grape spirit can be added to partially fermented grape juice. This stops the fermentation and retains much of the grape sugar. This method is used to produce sweet red wines. Examples are:-

  • Port.
  • Banyuls or Maury from Southern France.

Cheese links

Conclusion

Cheese and wine – a match made in heaven.

Drinking wine on an aeroplane – a disappointing experience

Wines are usually disappointing if you drink them on a plane. The circumstances are unusual, with conditions affecting both the wine and the drinker.

wines to drink on an aircraft

wines to drink on an aircraft

What is unusual about aeroplanes:-

  • Aircraft are pressurised at the equivalent of around 8,000 ft altitude, which is about three-quarters of that at sea-level.
  • Air-conditioning reduces the humidity to around 10%, much lower than most people are used to.
  • There is a lot of vibration.

Affect on the wine:-

  • Low pressure reduces solubility of gases such as oxygen and carbon dioxide, and this reduces the wine’s freshness.
  • Red and white wines are usually served too warm, which has a significant influence on the taste and smell.
  • Wine is rarely served in a decent glass, and this has a negative influence.
  • Wines can be severely shaken up, which doesn’t help.

Affect on you:-

  • The low humidity has a direct influence on your nasal passages, and hence your sense of smell and taste.
  • You also salivate less in conditions of low humidity. Saliva moderates astringent tannins in wine, so a wine appears more astringent than normal in an aircraft.
  • Flying is stressful and tiring, and all this affects your senses.

Conclusion

The conditions tend to suppress the fruit and sweetness of a wine, and enhance any harsh acidity and tannin. So, wines need to be carefully selected to compensate for this.

Sulphur Dioxide – the Magic Molecule

Sulphur Dioxide molecule

Sulphur Dioxide molecule

Sulphite additions to food and wine have become a big issue. However, the sulphites, and the sulphur dioxide that they produce have real benefits.

Why is the term sulphite used?
Sulphur dioxide is sometimes injected as a gas, but solid sulphite granules are usually added instead. The acid in wine rapidly splits this up to produce sulphur dioxide which actually does the work.

Sulphur dioxide occurs naturally in wine
This may seem unlikely, but fermentation of grapes produces sulphur dioxide without any help from humans. The amount depends on the the yeasts that are used, but it is a ‘natural’ product.

Why are sulphites added to wine?
There are two main benefits:-

  • Antioxidantif wine is exposed to air, the alcohol is quickly oxidised to acetic acid (vinegar). So, nature’s natural tendency needs to be moderated, if we are to drink the wine before it goes off. Sulphur dioxide attacks the chemicals which would otherwise produce vinegar. This is less of an issue for red wines which have their own antioxidants.
  • Antimicrobial – wine contains yeasts and bacteria. The magic molecule prevents these from multiplying and spoiling the wine.

Which wines have the most sulphur dioxide?
SO2 binds with many compounds in wine, including sugar. Only the unbound sulphur dioxide is able to fend off oxygen and microbes. So, sweet wines need plenty to protect them.

The importance of quality grapes
Rotten grapes make rotten wine, and need more sulphur dioxide to keep the bugs under control. Grapes with plenty of acidity also need fewer additions.

What are the adverse effects?

  • Sensoryan excess of sulphur dioxide produces a smell of burnt matches, but an awful lot needs to be added to have this effect. This fault is rare.
  • Healthis a difficult issue because there is little proof of adverse effects. It may induce asthmatic attacks in some people. It is worth noting that normal food metabolism in the body generates much more sulphites than you would absorb from wine consumption.

Conclusion
In my opinion, the addition of sulphites at the right time and in the right quantity is beneficial, if not essential, for almost all wine.

The serving temperature of a wine is important

A wine’s serving temperature is probably the most important factor in your enjoyment. It won’t make a great wine out of an average one, but it will make the most of what you’ve got.

Red wine serving temperature

Red wine serving temperature

Serving reds at room temperature
The adage used to be – serve a red wine at room temperature. That was fine in the days before central heating, but now ‘room temperature’ is usually over 20ºC (68ºF) , which is just too high. Any red wine is just bland if it is too warm.

White wine serving temperature

White wine serving temperature

Serving dry whites straight from the fridge
A domestic fridge can get a bottle down to 5ºC (41ºF), if you leave it in there for long enough. At that temperature the wine will just numb the taste buds, and you won’t smell much either.

Serving sweet white wines
These should be served well-chilled, 8°C to 10°C, 46°F to 50°F, is a good guide. Lighter sweet wines can be served at even lower temperatures. Lower temperatures make sweet wines less cloying.

Serving sparkling wine
Freshness is important in a sparkling wine, so its temperature should be lower than a dry white. Serving straight from the fridge at a little over 5ºC (41ºF) is ideal.

The affect of ambient temperature
Once a wine has been poured, its temperature will quickly move to that of its surroundings.

  • If it’s a warm day, then start the wine at a lower temperature.
  • If the weather is cold, then serve the wine at the correct temperature – you can always warm it up in your hands.

The 20 minute rule
This is as simple a rule as you are likely to get. 20 minutes before a meal:-

  • put the red wine into the fridge.
  • take the white wine out.

Alcohol levels in wine – high or low?

Alcohol levels in wine have increased significantly over the past 20 years. That is not to everyone’s taste, but are low and zero alcohol wines worth considering?

Why have alcohol levels increased?
There are several proposed reasons, including:-

  • Climate change – more heat and sunshine produces riper grapes with more sugar, and hence more alcohol.
  • Better practice in the vineyard, producing better quality grapes, with higher sugar levels.
  • The influence of certain wine critics, which encourages big wines with high alcohol levels.

What influence does alcohol have on your palate?
Alcohol stimulates nerve endings in the mouth, to provide a sensation of body and texture. It spreads flavours around the mouth, which persist even after the wine has been swallowed – known as the ‘aftertaste’. If the alcohol is too high, and is not balanced by the fruit, then the aftertaste may be bitter. If the alcohol is too low, then the wine is thin and unappealing.

Bottle of lower alcohol wine

A quality wine with 9% alcohol

Lower alcohol wines
The most successful lower alcohol wines (less than 10%) are those made in Germany. The fermentation is stopped short, and the wine may be sweetened by adding unfermented grape juice. This combination of lower alcohol, sugar and good acidity works very well indeed.

How low and zero alcohol wines are made
A wine has to be made by fermentation of grapes; this produces mainly alcohol, but also a host of other chemicals which contribute to a wine’s taste and smell. So the alcohol needs to be stripped out, but this is likely to remove other compounds as well.

Why drink very low or zero alcohol ‘wine’?
For the reasons stated, these ‘wines’ are a mere shadow of their former selves. So why not drink unfermented fruit juice instead?

Suggestions if you are worried about alcohol consumption:-

  • Look for wines from cooler regions of the world, which will have lower alcohol levels.
  • Drink less.
  • Add water to high alcohol wines. I know this may be sacrilege, but it is better than commercially stripping out the alcohol. Please don’t add fizzy drinks unless you hate the wine, as this completely disguises what you are drinking.

Why does a wine need acidity?

A wine which doesn’t have enough acidity is flabby and boring.

What is acid?
It is one of the five primary tastes – sweet, sour (acid), bitter, salt and umami (savoury). An example of an acid is citric acid in lemons. These tastes are detected by tastebuds, which are located mainly on the tongue, but also in other parts of the mouth.

acid and sugar in grape berries

How acid and sugar levels vary as a grape grows

How acid levels change as a grape berry grows
The diagram above shows that acid levels increase as a grape berry grows, but only to a point. Véraison is the moment when a grape berry changes, and starts to ripen; it softens, changes colour, sugar levels rise, and acid levels fall. Unripe grapes are hard and acidic, with little sugar. Over-ripe grapes are sweet and bland.

Which acids are present in wine?
Tartaric is the main acid, and its level stays fairly steady during ripening. Malic acid is the other significant acid, and this decreases after véraison.

Examples of two contrasting types of wine:-

  • Champagne – the grapes are picked with high acidity, and quite low sugar levels. In most wine regions the grapes would be considered under-ripe. At the end of production, sugar is usually added to take the edge off the acidity.
  • High alcohol Cabernet Sauvignon – these come from hot climates, where the grapes are picked very ripe, with high sugar levels and relatively low acidity. This sugar produces a wine with plenty of alcohol, and acid may be added to make the wine more palatable.

How can you tell how much acid is in a wine?
Unfortunately, very few wine labels provide this information, but the winemaker’s website often does. Acidity is usually stated as pH. I won’t bore you with a chemist’s definition, but pH is a scale in which water is neutral at level 7. The lower the number, the more acidic a liquid is, and wine is usually 3 to 3.5.

A balancing act
Acidity is particularly important in sweet wines, to ensure they are not bland. Sugar masks the acidity, so it may not be obvious, but all good sweet wines have it.