In most wineries, credit for the flavour of the wine goes to the fellow who makes it. But at Fetzer's, a prime winery in northern California's misty Mendocino County, they also like to heap praise on Keith Roberts: he is the fellow who makes the barrels. Master coopers are among the forgotten artists of the wine industry. Coopers' skills go back many centuries, and the precise way in which they make barrels would easily be recognisable in Bordeaux 500 years ago. Fetzer puts out a range of stunning wines labelled, for very good reason, 'barrel select'. This is because winemaker Dennis Martin has not only carefully selected the grapes that make the wine, but has also chosen the handmade barrels in which those wines will ferment and mature. The company claims to be the only one in North America to run its own cooperage in the winery. Mr Roberts picks heartwood from French and American oaks, then ages the wood. The staves are bent into shape after being softened by fire; it is this heating and burning - the toasting - that helps shape the character of the wine. The burnt oak and the natural flavour of the wood allows the winemaker to add depth to the wine. In many wines, the oak can be as important as the grape vine. The '95 Fetzer cabernet sauvignon barrel select is a very good example. Imported by Caldbecks and on sale for $175 at Park'n Shop, it is a wine of great elegance and enormous flavour. You get hints of currants on the nose and the taste is ripe with chocolate, vanilla and, of course, oak. This wine is too big to be drunk alone - you need a companion to discuss the wine with and you need some good food to accompany the drink. I opted for a nicely-grilled sirloin steak with garlic and onions. In 1985, the growing Fetzer wine company bought a local market garden company called Valley Oaks. The farm was famed for its organic gardening techniques, and these were partially adopted by the winery. The winemakers were keen to see if 'earth-friendly' farming could co-exist with modern winemaking, where you not only have to make excellent wines, but also turn a profit. Basically, the viticulturists have to feed a healthy soil with compost, instead of artificial fertilisers, and to use cover crops such as clover between the rows of grapes. Instead of pesticides and herbicides sprayed on the vines to combat insect pests, the organic farmer introduces lady bugs and insect-eating wasps. Today, all 140 hectares of Fetzer vineyards are certified organic. Unlike many Californian wineries, some of which are hyper-pretentious or vastly expensive, it is a pleasure to visit Fetzer. They have a relaxed country air. They also have a delicatessen where you can buy bread, cheese and salad and take that and a bottle of wine outside to commune with nature. Sitting under a giant redwood sipping your wine, you can get that distinctive taste of oak created with such effect for the barrel select range of wines.