Until the early 1990s, the St. Francis estate's 70 acres of Merlot vineyards were sufficient to meet its needs for this variety. As St. Francis' reputation for producing benchmark Merlot grew, however, a search began for vineyards yielding fruit compatible in quality and personality to that of the estate vines. Fruit for St. Francis Sonoma County Merlot is now sourced from the McCoy and Nunns Canyon vineyards on the western slope of the Mayacamas Mountains and from the Hunter Ranch at the foot of Sonoma Mountain, as well as from the fully-controlled Wild Oak vineyard and the St. Francis estate.

Production draws on approximately 200 acres of vineyards of two microclimatic profiles. The mountain vineyards lie on well-drained volcanic and red clay slopes at an elevation sufficient to provide abundant exposure to sunlight yet sited such that temperatures are sharply cooled at night by prevailing winds. The gravel, rock and loam soils of the Wild Oak and estate vineyards are nearly identical, and are situated in a cooler microclimate moderated by breezes from the Pacific Ocean and the San Francisco Bay and characterized by morning and evening fogs. These cool night temperatures are critical to the development of complex fruit of superior quality. The vines are drip irrigated, and depending on site, yield three to five tons of grapes per acre. Canopies are thinned in the estate vineyard to increase exposure to sun, concentrating color and flavor. Depending on maturity, harvest occurs between mid-September and the end of October.

The fruit is hand-harvested, brought to the winery and crushed into temperature-controlled stainless steel tanks. When the tanks are two-thirds to three-quarters full, the must is inoculated with selected yeasts and yeast nutrient. Fermentation takes place at temperatures of up to 85° to 90°F over a period of eight to 15 days, and once fermentation is underway, the juice is pumped over the cap of skins three times daily for a half hour each to extract maximum color. Toward the end of the alcoholic fermentation, a culture is introduced to initiate the malolactic fermentation; the wine is pressed from the skins into fresh stainless steel, where malolactic fermentation is completed over four to six weeks.

The lots are racked into French and American oak barrels of up three years' age, of which 25 to 30 percent are new, and remain separate during the 19 to 20-month aging period. Depending on the vintage, origin of oak is in proportions of 20 to 40 percent French oak, which lends refined, toasty, vanilla notes; and 60 to 80 percent American oak, which contributes tannic structure and cedar and tobacco notes. The barrels are topped roughly once every three months. At the end of the term in oak the blend is assembled, and unless it has not clarified sufficiently in barrel, the wine is bottled without filtration and held for eight months prior to release.

St. Francis' interpretation of this varietal is a full and intense expression of the grape in a distinctive Sonoma style. The perfumed aromas of plummy black fruit and spicy herb and vanilla nuances are confirmed in the ripe, lush flavors. On the palate, the fruit is rich and full with hints of chocolate, set in a structure of generous, round tannins which are carried into the persistent, mouthfilling finish.