Grapes ahead of the Bordeaux 2015 harvest at Chateau Larroque  Credit: Jonathan Ducourt / Twitter

Chateau Haut-Brion said it was likely to begin its Bordeaux 2015 harvest for Sauvignon Blanc and Sauvignon Gris at the end of next week, but a final decision was yet to be taken.

A summer heatwave is expected to cause a relatively early wine harvest across many northern hemisphere regions in 2015, from Piedmont and Rioja to Napa Valley in California and British Columbia in Canada.

Bordeaux’s wine bureau (CIVB) said the first red grapes should be harvested in mid-September. Around 6,500 seasonal pickers will begin arriving in the area over the next few weeks.

Grapes in many Bordeaux vineyards have finished their veraison – the colour change process – and maturity was well advanced for Sauvignon Blanc, Colombard, Merlot and Cabernet Franc, according to the regional Chamber of Agriculture.

Later ripening Semillon and Cabernet Sauvignon were mid-way through colour change.

Jonathan Ducourt, whose family owns 16 properties across six appellations, said vineyards were 15 days ahead of 2014. Potential alcohol for Sauvignons was at 10.8%, with acidity likely down on last year and picking to begin on 1 September. The first Merlots in Castillon should be picked around 15 September.

Bordeaux saw 61 hours of sunshine more than the 30-year average in June, and 30 hours more than average in July, a month that also only saw 18mm of rainfall compared to 80mm in 2014 – although this varied widely by appellation.

Nicolas Audebert, of Chateau Canon in St Emilion and Rauzan Segla in Margaux, said, ‘Sanitary conditions are very good, and [with recent rainfall] we have more water than we did four weeks ago, so the grapes are a better size.’

José Sanfins, of Chateau Cantenac Brown in Margaux, told Decanter.com, ‘Winemakers are always worried about something. But this year it is hard to find things to complain about.’

Edited by Chris Mercer