Gray Simpson from Corks Out in Heswall writes for One Foot in the Grapes explaining what to expect from Sauvignon Blanc grapes
Many Californian Sauvignon Blancs are labelled Fume Blanc. This is not just a homage to Pouilly Fume, but also reflects the fact that they will have either been barrel fermented or barrel aged, thus lending a toasty, smoky edge to the wine.
When this is done well, it can create a well rounded, very balanced, creamy Sauvignon Blanc, with a definite smoky style and with the acidity naturally being tempered by the oak barrels (compared to the rapier-like acidity of those Sauvignons fermented and aged in stainless steel tanks).
Besides the smoky, toasty characters, aromas of gooseberry and grapefruit are common, with a definite background of freshly cut grass. The acidity is evident, but not in your face.
The best of the Sauvignon Blancs come from vineyards to the west of California, where cooling Pacific breezes temper the natural heat. Those vineyards planted higher on the hillsides will get the best of these breezes and the wines will be vibrant and fruity, not dull and flabby with minimal acidity as can happen with grapes harvested from lower-lying valley floor vineyards.
Because of the nature of Californian wines, prices aren’t cheap, so expect to pay around £15 per bottle minimum for any decent Sauvignon Blanc.