Apples generally ripen in the fall, but the Sonoma gravenstein arrives in early August. This sweet-tart apple first came to Northern California with Russian trappers. It often looks glazed with red on a background of chartreuse. While Gravensteins make ideal pies, sauce and snacks, they’re losing ground to other varieties. Slow Food USA now includes them on their Ark of Taste, a list of endangered foods. Do your part by eating these beauties slipped into grilled sharp-cheese sandwiches or bathed in brown sugar and cinnamon for tarts.