Hand picked bunches of Chardonnay and Pinot Noir are crushed into a selection of predominantly seasoned French oak barriques for vinification by Petaluma's own strains of yeast. Upon completion, batches are inoculated to a bacteria isolate for malolactic, adding complexity to the wine while softening the high natural acid. Components are then assembled and treated to a secondary fermentation in bottle. The finished Croser is aged on yeast lees for a minimum of three years before disgorgement, liqueur dosage and reseal.