The Petaluma Evans and Sharefarmers Vineyards are shoot and crop thinned by hand to one bunch per shoot. Batches of hand harvested Cabernet and Merlot, in almost equal proportions, are crushed and chilled. After a short maceration, the fermentation is started by the addition of a special Petaluma native yeast culture. The fermentation is conducted with a submerged cap of skins fermenting at a high temperature. The cap is bathed daily in the cold juice for twenty one days prior to draining and pressing, then immediately gravitated to barriques for malolactic in new French Alliers and Never oak barriques. Petaluma is then racked to clarity over twenty months of maturation, and bottled without filtration.