Olive trees at the Castello del Trebbio in Tuscany; olive oils (Frantoio single varietal, the Castello del Trebbio blend, and the Castello del Trebbio blend gone rancid) laid out for tasting in the castle courtyard. Instead, olive oil growers Anna Casedei of the Castello del Trebbio in Tuscany, and Kathryn Tomajan and Robin Sloan of Fat Gold in Sunol, California, lead us through harvesting, milling, and, most importantly, tasting, in order to equip us to buy, use, and love olive oil nearly as much as they do. In addition to growing olives and making oil, she serves on the Florence Chamber of Commerce as an official extra virgin olive oil taster.