Grate cheese. Grate the cheddar using the large holes of a box grater.
Mix base. In a large bowl, add the grated cheese, pimentos, onion, garlic powder, cayenne, black pepper, salt, and Worcestershire sauce or pickle juice, if using.
Beat to combine. Using a hand mixer on low speed, beat in 1/2 cup mayonnaise until just combined. Add more mayonnaise, 1 tablespoon at a time, beating briefly between additions, until the mixture is creamy and spreadable.
Control the texture. Mix just until combined—you want it creamy but still slightly textured, not completely whipped smooth.
Chill. Cover and refrigerate for at least 1 hour before serving.
Serve. Serve with crackers, celery sticks, crostini, sandwiches, or as part of your favorite Southern appetizers.