To blanch asparagus, heat 4 quarts water (add 1 tablespoon salt, if desired) in 6-quart Dutch oven to boiling. Add asparagus; cook 3 to 4 minutes or until asparagus is crisp-tender. Remove asparagus, and immediately immerse in bowl of ice cold water. Let stand 5 minutes. Drain well; pat dry with paper towels.