How do tannins affect the flavour of wine?

Some types of red wine make your mouth feel ‘dry’ when you drink them. New research into why this happens finds out why tannins affect the flavour of different wine types.

The character and quantity of red wine tannins are often affected by different factors. These include how thick the grape skin is, the climate of the growing season and how the wine is cellar stored.

 

Different wine types affected by tannins

Researchers have published their findings in the latest issue of the Journal of Agricultural and Food Chemistry regarding the effect of tannins. They show that the tannins in Cabernet Sauvignon, for example, are more numerous, contain more pigment and are physically larger than the tannins in Pinot Noir.

They experimented by extracting tannins from a Pinot Noir and a Cabernet Sauvignon and discovered that tannins from Cabernet form more protein in saliva. This backs up previous research that shows wine can cause a dry mouth sensation when proteins in tannins and saliva interact.

 

What are wine tannins?

Tannin is a polyphenol that appears naturally in plants, wood, leaves, seeds, bark and, of course, fruit skins. In wine, tannins add astringency, bitterness and complexity of flavours.

Wine tannins are usually present in red wines however it is possible for tannins to be present in white wines if they are oak aged. Tannin is dry and tasted in the front part of the mouth as well as the middle of the tongue. An easy example to try of pure tannin is in unsweetened black tea.

Tannins in wine come from either the grapes or the wood of the barrels it’s aged or stored in. Grape tannins are in the stems, skins and seeds of the grape, and as red wines have more contact with the skin there is more time for tannins to dissolve in the liquid. On the other hand, wood tannins dissolve in wine if they are in contact with the liquid.

Examples of red wines that are high in tannins include Petite Sirah, Monastrell, Nebbiolo and Cabernet Sauvignon. Lower tannin wines include Zinfandel, Grenache and Pinot Noir, which is why the researchers used Cabernet Sauvignon and Pinot Noir to discover more about tannins.

 

Different factors affect wine taste

The researchers also found that tannins don’t make these changes happen on their own. Other factors within wine affect the tannins and how they affect the flavour and taste of the wine.

In the article, the team of researchers say: “When the opposite type of tannin was put into Cabernet or Pinot wines, the sensory panellists could not detect differences in dryness. For example, when Cabernet tannins were added to a Pinot wine, the drink appeared to have the same dryness as the original Pinot.”

They also point out that aromas from the wines would also have influenced the test panellists’ perception of the flavour of the wine.

 

Which trends will dominate the wine industry in 2019?

Wine may be considered a luxury for many people, but the way the wine industry reacts to challenges often shapes the way consumers make their choices.

There are lots of reasons why people buy wine. For example, it’s the most gifted product at Christmas. But according to a 2018 study on the habits of wine consumes, 79% of wine buyers just like the taste, indicating they are not swayed by origin or ingredients. The survey also showed that 80% of people say that the cost is the main factor to consider when choosing wine.

Wine industry reacting to consumer tastes

Getting value for money will remain top of the list for the average consumer in 2019. As many countries are going through a period of political and economic changes, this inevitably affects the way people choose to spend their money. Often, this means more people spending less.

In the US, the relative strength of the dollar means certain German wines are more affordable. German Rieslings are likely to be popular, as buying trends pick up after a slow few years. Other great value options for UK and US buyers include rosé from French regions outside of Provence. For example, rosé from Loire, the Rhone Valley, Bordeaux and Gascony will be popular next year.

Environmental impact on wine-making

This year has been phenomenal for UK wine makers, with the biggest and best grape harvests likely to lead to a bumper vintage. And while this is a positive side-effect of rising temperatures, it also shows how much the wine industry must adapt to the new normal. Weather patterns are far more unpredictable, and this will continue. Winemakers are taking note of the changes in climate and their effects on the industry all over the world.

In California, winemaker Laura Diaz Munoz says that increases in temperature and the corresponding stress on water supply are among the environmental concerns for 2019: “Cooler regions are not cooler regions anymore.” She suggests that the industry will adapt by planting in new regions and changing varieties of grapes to match the climate changes.

Owner of Garden Creek Ranch Vineyards & Winery in California, Karin Warnelius-Miller agrees. She says: “In California, we are now living in a different reality than years past. Fires, smoke taint and drought – these are our dominant concerns for 2019 and into the future.”

Health and well-being

As well as the effect on wine-making from climate change and a drive towards value by consumers, 2019 will likely see a continuation of people balancing alcohol intake. Wine is being enjoyed more as part of a meal than as a standalone drink, and there is a corresponding interest in lower alcohol options. Journalist and expert on trends in the wine industry, Deborah Parker Wong says: “The wine industry’s commitment to education is exemplary and the emphasis on consuming wine with food is ever present.”

These are just some of the industry and consumer trends that will affect how people choose their wine as we move into 2019.

Why the Rhineland is a must-visit for wine lovers

Whether used to buying wine online or tasting different vintages at events, wine lovers will love exploring the Rhine.

The Rhineland-Palatinate region of Germany produces more than two-thirds of the country’s wines. It covers six of the 13 wine regions in Germany and covers a massive 159,000 acres of vineyards. All of which make it the ideal choice for wine aficionados.

Beautiful Middle Rhine

For the most visually stunning option, choose the Middle Rhine. This runs through a valley liberally lined with castles among Unesco listed countryside. Most of the wines from here are white, with varieties including Rieslings made from the Silvaners grape. This is known as the ‘queen of grapes’ thanks to its delicacy. Among popular reds from the region are the deep red Portugiesers and the drier Dornfelders.

Most cruises down the Rhine sail between Amsterdam and Basel, with loads of stops on the way. A popular highlight is the town of Rüdesheim, which makes its own wine. It’s home to one of the best-known streets in Germany, the Drosselgasse, which is crammed with taverns serving up local specialities.

When you’ve tasted enough of the wines, you can take in a panoramic view of the region’s vineyards via a cable car trip up the Niederwald Monument.

Wagner vineyard

The largest vineyard in the Middle Rhine is the family-run Wagner. You can try wines from the vineyard at the Weinhaus Wagner, which is in Koblenz. This beautiful city sits at the confluence of the Moselle and Rhine rivers.

Further down the Moselle river, you will find Bernkastel-Kues. This has an interactive Wine Museum, which offers virtual flights over the vineyards to interested visitors. You can also taste wine in its old cellars. The Cologne Wine Museum is also worth a visit. It’s difficult to miss, as it has its own vineyard on the roof. It’s packed with more than 40 different varieties of grape and inside, the museum follows the history of wine from the Romans all the way up until the present day.

Wine festivals and events

There are loads of wine festivals along the Rhine, particularly between spring and autumn. The peak season for wine-orientated events is August and September. A highlight is the Bernkastle-Kues festival during the final weekend of August. It’s famous for crowning a wine queen and hosting a spectacular vintners’ parade.

The main festival is called Rhine in Flames, which marks the beginning of the harvest season. Held over five weekends between May and September, it boasts massive firework displays lighting up the river at different locations. Various historic buildings and castles are lit up at night, making for stunning views along the river.

Most organised cruises include regional wines served with dinner, and you can always buy your own and bring back on board along the way. Many cruise providers cater for wine lovers with cruises including talks by experts, guided tastings and loads of visits to cellars and vineyards.

How to spot a corked wine

If you’ve ever tasted a glass of wine that seemed a little ‘off’, but you weren’t sure why, then it could have been corked. Everyone has heard of corked wine, but many people don’t know exactly what it means, or know how to recognise it.

Around 5% of all wine around the world is thought to be corked, which can mean an unpleasant drinking experience for you, and perhaps a ruined meal or two. The first thing to do is sniff the bottle before you taste. If it smells normal, then give it a taste. You’re looking for fresh, strong flavours that are untainted by oxygen or yeast. If it is corked, then you should take it back or inform the waiter and expect it to be replaced. Here’s how to spot whether your wine is corked.

  1. Sniff it

If your wine is corked, you’ll notice an odour straight away. It will smell musty, or reminiscent of wet dog, wet newspaper or damp towels. Your first inhalation is the most reliable indicator, as later sniffs can get used to the smell. Trust your first sniff! Wine becomes corked when exposed to a compound called ‘2,4,6-Trichloroanisole’, more commonly called TCA. This is found in the cork itself.

  1. Taste it

If your wine has only been slightly exposed to a small amount of TCA, the sniff test may not be enough to tell you for sure whether it’s corked. Give it a taste and see whether it seems dull and less fruity than it should be. Some people pick up an astringency from corked wine. A wine that has only been slightly corked can lack taste and smell.

  1. Test it before serving

If you’re eating out, then make sure you’re allowed to taste the wine before it’s served to everyone else. This gives you the chance to send it back if it is corked and order a replacement.

  1. Don’t confuse other problems with being corked

Just because your wine seems a little off, it doesn’t necessarily follow that it’s corked. Other factors could have affected the taste. For example, if the wine is exposed to oxygen it can taste lifeless and a bit vinegary. Maderised wine means it has been overheated and has a flavour tinged with almonds. It’s also possible that the wine was re-fermented, which causes a fizzy sensation and flavour.

Scientists create ‘supergrapes’ to combat fungal attack on vineyards

Growing vines that are impervious to rot or any parasites is surely the dream for wine makers. And now, scientists in France have made that dream a reality by creating four supergrape varieties that they say need almost zero pesticides.

However, traditional vineyard owners say that the supergrapes could lead to lesser quality ‘Frankenstein’ wine in the future. This is because they mix grape genes from different regions and grow the creation in labs, therefore diluting the purity.

Visually identical

The white and red grapes currently growing at the National Institute of Agronomical Research in Colmar, France, look just the same as any other you’d see in the region. But they’re very different.

They’re grown the lab as part of an ongoing programme named “Resdur”, which aims to create grapes that are “durably resistant” to any kind of fungi, including the two that can destroy whole crops: powdery and downy mildew

Over the last few months, scientists at Inra have been given permission by the state to grow four different supergrapes. Named Araban, Floreal, Vidoc and Voltis, wines made from then will be bottled next year and in 2020.

Decades-long research

Growing grapes that are resistant to rot isn’t a new idea. First attempts to do so started in the 1970s when scientists singled out a resistant gene. Since then, Inra has identified three more by crossing European, Asian and American grapes.

The man in charge of Inra is called Didier Merdinoglu. He says that the grapes will allow winemakers to reduce pesticide use by up to a whopping 90%: “We are talking about dropping from an average of 15 treatments per year to one or two, above all to kill off other diseases and parasites.”

Environmental breakthrough

As 20% of all pesticide use in France is concentrated onto vineyards, even though wine grapes consist of just 3% of the country’s crops, researchers say that these new grapes could be an environmental breakthrough. It will also make growing grapes cheaper for the owner.

France is under increasing pressure to reduce pesticide use fast, after a number of cancer cases among vintners. However, some winemakers remain resistant to the idea of a supergrapes.

They say that grapes grown in the lab could decimate centuries of careful growing traditions that have melded European crops with the local soil, producing subtly different varieties of wine. They say that replacing cultivated grapes with cheaper, much more robust but artificially cultivated ones will mean wine lacks the quality and flavour of the existing regional varieties.

Not GM

These grapes aren’t genetically modified, but purists worry that crossing over different varieties from around the world will lead to “artificial and unnatural ‘Frankenstein wine’”. One said: “This is like crossing a monkey with a man: it may be technically possible, but it goes against nature.”

While that may well be hyperbole from a traditionalist, France must lower pesticide use somehow and it’s likely that this will be the fastest way to hit their targets.