Step 1

In a large bowl, whisk the sour cream, the vinegar, the sugar, and the pepper together until blended.

Step 2

Add the cucumbers and the onions to the sour cream mixture and toss to coat.

Step 3

Refrigerate the cucumber mixture, covered, for at least 4 hours and up to overnight.

Step 4

Serve the cucumbers with a slotted spoon.