(Wine-Searcher) - In his third report from Bordeaux, Adam Lechmere finds that uneven tannin levels caused headaches for producers.

Across Bordeaux, the long, hot, dry months of June and July produced grapes with thick skins that could be exceedingly high in tannin. Some winemakers say the tannin index – the IPT or indice polyphenols totaux – is the highest they have seen for many years.

At Château Palmer in Margaux it was "huge in 2015 – 80ipt," managing director Thomas Duroux told Wine-Searcher. The average would be around 65ipt, he said.

"You should never forget that this is a tannic vintage. June and July without rain built up a quantity of tannins in the wine," Pierre-Olivier Clouet of Cheval Blanc said. He added that the cool late August and September softened the tannins: "Spring and early summer was about quantity of tannins, late summer was the quality of the tannins."

"Tannin management was key this year – it was vital during the extractive process," said Christian Seely, who runs Château Pichon Baron among other properties. "There was lots of potential tannin so it was important to have subtle extraction."