Modeled after ancient Chinese water-lock jars, Sarah Kersten’s fermentation jars have gained repute for both their form and function. “I aspire to create pieces that are sculpturally beautiful, effortlessly functional, and of heirloom quality,” she writes on her website. Kersten’s designs respond to real needs, whether from her kitchen or other people’s kitchens. In her Berkeley, California studio, each stoneware jar is high-fired for durability and lined with an easy-care, food-safe glaze. They come with a set of weights to keep vegetables submerged, and are available in white or gunmetal gray with either a matte or gloss finish. To keep up with demand, Kersten’s jars are now slipcast from molds of handmade pieces.