Napa Valley wine producers are hoping to replicate the famed Bordeaux style with their 2011 wines.

Chris Phelps, winemaker at Swanson Vineyards, told Decanter that the grapes from the 2011 harvest, which has just got underway, are "very Bordeaux-like".

The main features of the grapes are good balance, high acidity, alcohol content that is lower than normal, and the potential for ageing.

However, the harvest has been beset by problems with rain, which brings the usual hazards of rot, mildew and dilution.

Mr Phelps insists that the rainfall, which measured 3.8cm between October 3rd and the 6th, "shouldn't be a major setback", causing "delay rather than disaster".

However, others are worried about whether the grapes can be picked before the rain decimates yields.

Shafer Vineyards winemaker Elias Fernandez says that the crop is at the mercy of the rain, while Bob Biale of Robert Biale Vineyards has reported "frantic" picking of early ripening grapes.

Much like Bordeaux, the growing season in California has been a break from the norm this year. Many days were uncharacteristically cool with no significant heat spikes, meaning that the grapes developed more slowly.

Producers therefore decided to leave them on the vine for longer, but this left them exposed to the October rains.

Overall, growers are very pleased with the quality, but some have seen a significant reduction in yield.

As Terry Hall of Napa Valley Vintners told Decanter: "It's exceptional fruit so far, and everyone wishes there was a lot more of it."

The current standing of Californian Napa Valley wines owes a great deal to the efforts of one man - influential wine critic Robert Parker - whose reviews in The Wine Advocate elevated a number of estates to new heights.

In February, Parker announced he would be handing over responsibility for rating Californian wines to Antonio Galloni, who has promised a shake-up of the reviewing system.