In a medium-sized bowl, whisk together the buttermilk, sour cream and lemon juice until smooth.
Add the garlic, salt, pepper, paprika, dill, chives, and parsley, whisking until evenly combined.
Dressing can be used immediately or stored in an airtight container in the refrigerator. Leftover dressing will keep in the refrigerator for up to 4 days.
Do not use buttermilk powder or buttermilk substitute made from milk and lemon juice. Use real buttermilk!
Many buttermilk ranch dressing recipes use mayonnaise, or a combination of mayonnaise and sour cream. I prefer using all sour cream. If you want to add in some mayo, I recommend swapping out 1/4 of the sour cream (so 1/2 cup sour cream + 1/4 cup mayonnaise total).