This is a longer version of an article also published in the Financial Times.
Over the last few years I have become increasingly aware of a new phenomenon in a worrying proportion of red wines. These wines leave my palate feeling as though it has been energetically scoured by sandpaper, steel wool or a scrubbing brush. Typically they smell rather winning and opulent. They enter the mouth all big, ripe and flattering. But by the time I have swallowed or, much more likely, elegantly expectorated them (I just couldn't write the word 'spat'), the inside of my mouth feels pinched, raw and dry, as though it will never again know the soothing effect of saliva.
Since we all have different physical capabilities and sensitivities, as well as different likes and dislikes, I assumed that this reaction to them was intensely personal. But recently James Forbes, who was a buyer for Oddbins wine stores and now represents Argentine wine in the UK, wrote to me out of the blue describing exactly the phenomenon mentioned above and asking whether I had any idea what explained it. I should add that although he finds it on a number of Argentine wines, he also encountered it when buying wines from North America, South Africa, Portugal and southern France for Oddbins. I find these wines with a drying finish tend to be more expensive, more ambitious wines from both Spain and Argentina, a few from Chile and South Africa, lots of Australian reds and a certain proportion of smart red bordeaux – from both sides of the Gironde. I shall publish a list of examples from my recent New Wave Spanish tasting here on Monday.
What has changed in winemaking in the time I have noticed this phenomenon is that grapes are picked later. As grapes ripen, sugar levels rise, acid levels fall and the phenolic compounds in the grape skins – tannins, pigments and flavour compounds – evolve. The fashion for later picking, or extra 'hang time', is less because winemakers actively seek higher levels of fermentable sugar, and therefore more alcohol in the resulting wines, and more that they have come to view the astringency associated with tannins as undesirable.
Tannins act as a preservative in red wines and taste not unlike cold tea, drying the inside of the mouth. Traditionally young red wines were always high in both tannins and acid. Wine drinkers accepted this and kept wine until it tasted gentler and softer once the tannins had formed softer-tasting compounds or had been precipitated in the form of sediment in the bottle. Today wine drinkers are much more impatient however and want to enjoy wines almost as soon as they are released, so increasingly wine producers have been picking the grapes when the tannins have softened as much as possible – even at the expense of much lower acidity. In most wine regions, if the acid in the grapes is too low, they are allowed to add extra tartaric acid, the acidity most commonly found in grapes. And in many regions, if alcohol is too high, they are allowed to add water or use technology such as the so-called spinning cone to remove alcohol. But keeping grapes on the vine is by far the easiest known way to tame tough, chewy tannins.
I actually rather like tannin if it's well balanced by fruit, but this sensation is something different. I wondered whether these uncomfortably dry finishes might have something to do with oak. The rawness of the sensation on the inside of my mouth made me think of under-seasoned, 'green' oak. All ambitious red wines are aged in oak barrels nowadays, but the oak used for the barrels should ideally be 'seasoned', kept in the open air for many months while the oak's harshest tannins are leached out (leaving dark stains underneath the increasingly grey planks of wood).
I accordingly asked barrel broker Mel Knox, who represents prime French coopers Taransaud and François Frères in the US, what he thought might be causing the sandpaper effect. For him, the problem is people not spending enough on their wood. "If you have green oak and high alcohol the tannins in the mouth are covered up, but it all comes out in the finish. I think this happens when cheap winemakers try to imitate Helen Turley [California winemaker famous for super-potent wines]. When you age high alcohol wines in well seasoned wood, the results are good. But if you stint on quality oak, the result is that the alcohol sucks the harshness out of the barrel. My hypothesis is that when winemakers age high alcohol wine in heavily toasted, poorly seasoned barrels, certain compounds are extracted from the barrel that should have been left alone!" He also wonders whether American oak or oak chips or inserts are to blame.
Paul Draper, who has won worldwide acclaim for the consistent, and not overripe, quality of the almost 40 vintages he has made at Ridge Vineyards south of San Francisco, also reckons careless oak selection is the culprit. A prominent advocate of American oak, he says he would never buy from a single cooper but uses six or more, always testing and blind tasting to check that the quality of the oak suits Ridge fruit.
For a view from the other side of the Atlantic, and the other side of the barrel business, I asked Paul Pontallier, who not only directs Château Margaux and the making of its elegant wines, but has also been one of Bordeaux University's most respected authorities on oak. For good measure, he also makes wine in Chile, South Africa and elsewhere. He identified the problem of tannin maturity. "Grapes in most New World wine regions – and often in Spain as well - ripen very differently from how they do in Bordeaux; they accumulate a lot of sugar quickly and lose acidity before tannins get a chance to ripen well. This is actually why people – for good reason – harvest late, and make wines over 14.5 or 15% alcohol. The problem is that high alcohol reinforces the dryness of tannins, so that the remedy can prove worse than the problem. And low acidity obliges them to add tartaric acid, which also reinforces the dryness of the tannins."
Pontallier then identifies the common habit of over-extraction, leaving the young wine in contact with the skins for an extended time in an effort to extract tannins from them, as exacerbating the problem. "When you have potentially bad tannins, you should be rather careful about not extracting them! And that is not to mention the fact that oak, for totally unknown reasons, can sometimes not integrate well with the tannins, especially the dry ones…"
And finally, a southern hemisphere view. The most admired winemaker in South Africa, André van Rensburg of Vergelegen, was in London last week so I asked him whether he had also come across sandpaper reds. He smiled knowingly. "When you find these wines, you can be sure the winemaker is trying to look for no grape tannin, just oak tannin. You can bet your last pound the wine was all matured in very tight grain, new French oak and because there are no grape tannins involved in the maturation process you have wood tannin only, and that leads to this sensation. I cannot believe that these wines are going to mature beyond five to eight years because they were made from grapes that went beyond physiological ripeness. With grapes, after greenness comes ripeness, then overripeness, and then dead fruit. I think a lot of those wines are made from borderline dead fruit."
If so, it would seem that there is no shortage of sandpaper beyond the grave.