Roussanne's origins lie in the central Rhone region of southern France in the Isere Valleys. When it originated is not known. It's more recent history is well documented however. In the mid 20th century, many of the plantings in France became infected with fanleaf virus and were subsequently replaced with the less interesting but more resilient and consistent producer, Marsanne. It was originally believed to have arrived in California in the 1980s but all was not as it seemed. A rather long and drawn out saga ensued and the result is that the original source of California Roussanne turned out not to be Roussanne at all but rather Viognier. Although the entire saga is somewhat amusing if viewed from the periphery, its clear that even in today's world of modern genetic testing and carefully propagated cuttings, one mistake in sourcing a Varietal type can have far reaching and long lasting effect. Feel free to click on the following link for the complete story as told by renowned wine expert Jancis Robinson. http://www.jancisrobinson.com/articles/jr405
Roussanne is generally regarded as one of the less economical French Varietals to produce because it is extremely finicky about growing conditions. It isn't a big producer, is susceptible to a number of rots and mildews. To top it off, it ripens late making rot even a bigger problem in regions where mid to late fall rains are prevalent. Roussanne needs a dry, sunny climate and is one of the earliest to bud making it a good Varietal for California's mild and generally predictable spring weather. It is moderate in canopy growth so excessive thinning is not usually required. Its grapes are generally considered light russet in color (light brown with orange) leading some to believe that this is where the Roussanne name came from but there is no real evidence to support this conclusions.
Despite all the reasons why Roussanne should followed the dinosaurs down the path to extinction, it does have several redeeming qualities. Unlike many of the other white Rhone Varietals, it has more acidity making it an outstanding blending grape to counter balance the lower acidity or Marsanne or Viognier and if handled with care, can make an interesting Varietal by itself.
If a Roussanne is well made and retains some acidity, it will age very well for a white wine. Most California Roussannes can be cellared for 5 years and a number of French offerings continue to improve even 10 years after harvest.