© Château La Conseillante

Merlot was one of several star performers on the Right Bank in 2015.

In the first of his reports from Bordeaux En Primeur, Adam Lechmere looks at Graves, Médoc and the Right Bank.

Critics and vignerons will argue for many months about whether 2015 is a great vintage or just a very good one, but it is certainly fascinating and unusual.

Brisk acidity, crunchy, ripe fruit and powerful tannins are strands that run through the most successful wines.

"It's a vintage of freshness," Fabien Teitgen, winemaker at Smith Haut-Lafitte, one of the celebrated grand cru classés of the Graves, told Wine-Searcher. "The key factor in 2015 was water," he added. First, the lack of it in June and July, and then the rain that fell in August, hydrating vines that were beginning to become stressed.

Graves and the Right Bank were particularly lucky with their rains. "It came just at veraison," Gabriel Vialard at Haut-Bailly said, "and it released essential nutrients in the soil." It was still an exceptionally dry summer in Saint-Émilion, with the lowest rainfall for 20 years, with temperatures higher than average from April to August.

The rain revived stressed vines, whose grapes were tiny, intense and tannic. Development continued through August and September, which were cooler than normal. Acidity and tannin were retained in the grapes while fruit developed, and vignerons were able to harvest in ideal conditions.

The ability to wait for optimum ripeness has been cited by many winemakers as key to the success of this vintage. Conditions were similar to the summer of 2005, but a decade ago they tended to harvest earlier.

As Guillaume Thienpont of Vieux Château Certan said: "The old school would have picked the Merlot at the end of August when they had technological ripeness, with the right alcohol and the acidity but perhaps not full skin ripeness. But because the weather was so good, we could wait."

The best wines have a classic profile – fine-grained tannins with excellent grip, juicy acidity, and then ripe fruit and an overall freshness. They have great capacity for aging.

Tannins are strong – particularly so in Saint-Émilion and Pomerol. Christian Moueix of négociant J-P Moueix, with properties across the region, told Wine-Searcher the tannin levels are "the highest I have ever seen". Alcohol levels can also be on the high side.

The singular weather conditions helped Merlot and Cabernet, Sauvignon Blanc and Semillon alike. Olivier Bernard at Domaine de Chevalier in Pessac-Léognan said: "The August rain saved the whites far more than the reds. The rain protected the acidity, which normally goes down in August." The best Graves whites are aromatic with well-balanced acidity and real energy, though there are more than a handful that lack backbone – it's by no means a uniformly excellent white vintage.

At Cheval Blanc, the Merlot was of such quality that it all went into the first wine – there will be no Petit Cheval in 2015. "The best blendings we tried were always made up of all the plots, so we decided to put all into the first wine," technical director Pierre-Olivier Clouet said.

"Merlot is a total success," Moueix said. "We were able to plan the harvest most successfully, leaving the grapes to reach full maturity." At Château Angelus, managing director Stéphanie de Boüard told Wine-Searcher she thought 2015 "among the very finest vintages of the château".

Everyone, it seems, is pleased. Alexandre Thienpont, the owner of Pomerol's Vieux Château Certan (and father of Guillaume) was so happy with his Cabernet Franc that he made it nearly 20 percent of the blend – compared with less than 5 percent in previous years.

At Haut-Bailly, Vialard even decided to use Petit Verdot from vines that were planted only three years ago, so intense were the grapes. "They were inky black, deep, full of spice and with wonderful grain to the tannins. They were explosive, mouthwatering."

The first tasting the wines of the Médoc was like going back in time, to the powerful, edgily tannic vintages of a decade and more ago. The finest of the wines – in Margaux, certainly – are fresh, bright and washed with juice, with pronounced tannins that grip from the beginning and don’t lose their hold until the very end of the palate.

Many wines manage to be both structured and dense, but light and airy. In Margaux, from the cru bourgeois Château Angludet to the third growth Château Giscours, the wines have delicacy and finesse, along with an iron grip that is unmatched in the rest of the region.

This side of the river suffered heavier and more prolonged rains than the south and the east (Saint-Estèphe had 118mm compared to the usual 35mm in September), and the Cabernet can show sometimes excessive tannins. The further north you go in the Médoc, the leaner the wines become, and some have ferocious tannic grip.

But more often than not, that is mitigated by the freshness of the acidity and mouthwatering juice. They are wines that will take some years to be ready for drinking and they have huge aging potential. Every commune of the Médoc produced ripe, balanced wines with depth and aging potential.

"The weather was atypical," Liliane Barton of Château Léoville-Barton and Langoa-Barton told Wine-Searcher. "We had an excessively hot June and July, and then storms in August. But we're very happy with the wines – they are probably the best we've made since 2009 and 2010. It's not a great vintage but it's very good."

Across Bordeaux gentle extraction in the vinification was key. The offerings from smaller châteaux can be unbalanced, with the astringency that comes from overextraction.

"The danger was to try to out-perform nature and to extract too much," Christophe Labenne, managing director of the renowned cru bourgeois Château Poujeaux told Wine-Searcher. He agreed the wines of the Médoc "need time" before they are ready to drink.

The quality of the fruit is in no doubt. "The Cabernet is incredibly successful," Claire Villars-Lurton, owner of Château Durfort-Vivens and Château Ferrière said. "It's the complete variety, it's got balance and tannins and it's very charming."

Every year at En Primeur there is debate as to whether the vintage favors Cabernet or Merlot, if it is a Left Bank or Right Bank vintage. This year such arguments are redundant.

"Everything was successful this year," Jean-Louis Triaud of Château Gloria and Château Saint-Pierre said. "That's the privilege of a really good vintage."