In a medium bowl combine nuts and enough water to cover. Let stand, covered, 7 to 24 hours; drain. (Or to quick-soak, cover nuts with boiling water and let stand 10 minutes; drain). Rinse and drain again. Meanwhile, remove 1 tsp. zest and squeeze 3 Tbsp. juice from lemon.
In a food processor or blender combine nuts, lemon zest and juice, and next six ingredients (through cayenne pepper). Cover and process or blend 5 to 6 minutes or until smooth.
If desired, chill hummus. Serve with dippers. Store in the refrigerator up to 3 days.