Until recently it was believed that up to the mid-19th century, Barolo was a sweet wine. This was attributed to the fact that the nebbiolo grape ripens late in October meant that temperatures would be steadily dropping by harvest. By November and December, temperatures in the Piedmont region would be cold enough to halt fermentation, leaving a significant amount of residual sugar left in the wine. Another popular credence was that in the mid-19th century, Camillo Benso, conte di Cavour, the mayor of Grinzane Cavour invited the French enologist Louis Oudart to the Barolo region to improve the winemaking techniques of the local producers. Using techniques focusing on improving the hygiene of the cellar, Oudart was able to ferment the nebbiolo must completely dry, making the first modern Barolo. This new, "dry" red wine soon became a favorite among the nobility of Turin and the ruling House of Savoy, giving rise to the popular description of Barolo as "the wine of kings, the king of wines".