It was established as California's 153rd appellation on August 30, 2024, by the Alcohol and Tobacco Tax and Trade Bureau (TTB), Treasury after reviewing the petition submitted by Rebecca Wood, managing member of Premium Vintners, LLC on behalf of Fallbrook Winery and other local vineyard owners and winemakers proposing the viticultural area named "San Luis Rey."
The hilltop mission overlooks the valley of the San Luis Rey River watershed that geologically defines the area that shares the name.
The low elevations and a terrain of gently rolling hills that are open to marine air almost eliminate the spring frosts that can affect vine growth at the beginning of the growing season.
The petition also notes that afternoon breezes help to prevent fungal diseases resulting from the morning's low cloud cover.
The petition notes that the AVA has lower average annual mean and maximum temperatures and fewer GDDs than the regions to the north and south.
[3] Winds in the San Luis Rey AVA are generally mild, most of the time less than 10 miles per hour (16 km/h); in the Fallbrook area less than 15 mph (24 km/h).
[7] During summer afternoons the area typically experiences persistent westerly winds from the coast which prevent the temperatures to rise as high as in nearby AVAs.
In fall and winter the area occasionally experiences strong, gusty flows of air from north or east, usually dry and warm.
The petition states that soils with low levels of organic carbon decrease grapevine vigor, leading to smaller canopies, clusters and berries.
Sandy loams also have low cation exchange capacity, which reduces the ability of vines to absorb nutrients from the soil and prevents overly vigorous growth.
[4] Euan Parker, the winemaker for Fallbrook Winery, one of the region's oldest brands, says the flavor of Cabernet Sauvignon bears more similarity to wines coming from Sonoma than Napa.
The Merlots tend to be the bolder and more powerful wines, and the Cabernet Francs “are more in the line of Saint-Nicolas de Bourgueil in terms of taste.”[8]