Add all of the ingredients to a bowl and mix well to combine. Check the seasoning and adjust with salt and white pepper as needed. Transfer to an airtight jar and refrigerate until ready to use.
Chef's Tips
Finely slice the chives rather than chopping them roughly — chives bruise and turn slimy if cut too coarsely or with a dull knife, which can make the ranch look muddy instead of fresh and flecked.Let the sauce sit in the fridge for at least 30 minutes before serving, if you have time — ranch is one of those sauces that genuinely improves once the buttermilk and herbs have had a chance to meld.Thin with a little extra buttermilk if using it as a dressing rather than a dip — the consistency as written is closer to dip thickness, and a dressing usually wants to be pourable.
Storage & Reheating
Refrigerate for up to 4 days in an airtight jar or container. Freezing isn't recommended, since the raw-egg mayo base and sour cream will split once thawed. No reheating required — this one's served cold.