Sauvignon Blanc is another white grape which is grown in France (Bordeaux and the Loire Valley) and throughout the New World. It can make a very aromatic white wine, and is usually dry. In cooler climates, the wine often takes on what wine people call an herbaceous quality. There are lots of words used to describe this herbaceous quality, such as grassy, vegetal, green pepper, asparagus, or even cat's pee. Yes, cat's pee! As an owner of a cat with a problem, I can tell you that it doesn't actually smell that foul. It smells more like a subtle hint of ammonia. It also often has some elements of fruit, like citrus or passion fruit. In warmer climates, the vegetal qualities often fail to develop, and a simpler peach or grapefruit flavored wine develops.
Sauvignon Blanc is usually aged in stainless steel, but does age in oak in some areas. Most notable among these areas is Pouilly-Fumé. This area is not be confused with Pouilly-Fuissé, which is a Chardonnay area. Confused yet? This is one of those things you just have to memorize. I find it helpful to remember that if you see Fumé, you know it's Sauvignon Blanc. Fumé means smoked in French, which refers to the oak used in the aging process. Oak, as I'll get into further detail later, can often add a smoky element to the taste of wine because the barrels are toasted during the cooperage process. When Sauvignon Blanc is aged in oak in Napa, it's called Napa Fumé Blanc, which is an attempt to copy the French style and labeling term.
Sauvignon Blanc wines are mostly made to be drunk young, when they are fruity and fresh. In the Loire Valley and in Bordeaux, however, the wines can age up to 15 years in the bottle. During this aging process, the vegetal notes develop and the fruit notes fade, which many people find very desirable. This happens in the Sancerre area of the Loir Valley, and as a result are very popular and therefore quiet expensive.