Clover Sonoma milks the pop-up trend in Hayes Valley

Milk is treated more like a fine wine than a simple source of nourishment at this Hayes Valley storefront. Clover Sonoma, the North Bay dairy, has jumped on a trend of companies using pop-ups — temporary stores that offer flash sales or distinctive experiences — to generate some extra attention. For the next month, the Clover Sonoma Milk tasting room will employ contracted milk sommeliers — or “somoo’liers,” as the company prefers — who walk customers through the nuances of different kinds of milk, from low-fat to whole. On a recent Wednesday, the store proved something of a tourist attraction, with visitors from Los Angeles and Washington.