Boil the Beets: Place beets in a large pot and cover with water. Boil until tender, about 30–40 minutes. Drain and let cool.
Peel and Slice: Once cool enough to handle, peel off the skins (they should slide off easily) and slice into rounds or wedges.
Prepare the Brine: In a saucepan, combine vinegar, water, sugar, salt, and any optional spices. Bring to a boil, stirring until the sugar dissolves.
Pack the Jars: Place the sliced beets into sterilized mason jars. Pour the hot brine over the beets, leaving about 1/2 inch of headspace.
Seal and Chill: Seal jars with lids. Let them cool to room temperature, then refrigerate for at least 24 hours before eating.
