The Best Homemade Ranch Dressing Recipe! 1 c. sour cream 1/2 c. buttermilk (add 1-1/2 tsp. vinegar to milk to equal 1/2 c. if you can't find real buttermilk) 1 TB. lemon juice 1 large garlic clove, minced 1 TB. dried parsley, or 3 TB. chopped fresh 1/2 tsp. onion powder 3/4 tsp. sea salt (or to taste) 1/2 tsp. black pepper 1/8-1/4 tsp. dried dill (to taste) or 1 tsp. fresh.