In a personal blender, pour in the buttermilk and measure and add in the mayonnaise, sour cream and ranch dressing mix.
Secure the lid and blend until thoroughly combined.
Pour into a jar with a tight fitting lid and refrigerate for at least 30 minutes. Overnight is best as it gives a chance for the flavors to develop.
After the flavors have developed, taste and add ¼ teaspoon salt if you feel it needs it.
