California's beautiful and remarkably fertile Sonoma Valley has grown over the decades to become one of the United States' most respected and profitable wine regions, with wineries within the region benefiting from the superb Californian sunshine, low rainfall and wonderfully rich soils. Because of this vital combination of excellent conditions, the region is able to grow a wide range of grape varietals for use in the production of an impressive array of wines, with many different red and white wine grapes flourishing each year and producing excellent and characterful results. The soils have been enriched by volcanic activity, and the presence of geothermal springs, which make this region a unique one, and very much the beating heart of California's ever growing wine industry. The precise origins of what became known as the Zinfandel grape variety are uncertain, although it has clear genetic equivalents in both Puglia and Croatia. However, when it was brought to the New World in the mid 19th century, it became known as the Zinfandel, and has been consistently popular and widely grown ever since. These very dark and very round grapes have a remarkably high sugar content, resulting in relatively high levels of alcohol in the wines they are made into, with bottles often displaying as much as fifteen percent. What makes the Zinfandel such an interesting grape, though, is the fact that the flavors produced by this varietal vary considerably depending on the climate they are grown in. In cooler valley regions, the Zinfandel grapes result in wines which hold strong flavors of tart and sweet fruits; raspberry, redcurrant and sweet cherry, held in a very smooth and silky liquid. Conversely, warmer regions result in more complex and spicy notes, including anise, pepper and hedgerow berries.