1-Cook the beets first using your preferred method (roasting is recommended for optimal flavor and color preservation). Allow the beets to cool completely, peel them, and slice them.

2-In a medium pot, combine the apple cider vinegar, water, granulated sugar, coarse salt, and dry ground mustard.

3-Bring the vinegar mixture to a boil, stirring until the sugar dissolves completely. Let it simmer for a few minutes, then remove the pot from the heat and allow the brine to cool slightly.

4-Place the sliced beets and whole black peppercorns into a clean glass jar with a tight-fitting lid.

5-Pour the cooled brine over the beets in the jar, ensuring all beet slices are fully submerged by the liquid.

6-Loosely fasten the jar lid and let the jar sit at room temperature until it reaches room temperature.

7-Tighten the lid securely and transfer the jar to the refrigerator. The pickled beets can be eaten immediately, but their flavor will improve significantly after a couple of days.

8-Always keep the pickled beets refrigerated and consume them within 6 weeks. This recipe is for refrigerator pickling only and is not shelf-stable.