Place the canned beets and sliced onion into a mixing bowl or large jar. Give them a quick stir to combine.
In a small saucepan, add the reserved beet juice and apple cider vinegar. Stir in the sugar and mix well.
Bring the liquid to a gentle boil over medium heat, stirring occasionally until the sugar fully dissolves. Once boiling, remove from heat.
Carefully pour the hot pickling liquid over the beets and onions, ensuring everything is well coated. Give the mixture another stir, then let it cool to room temperature.
Cover and refrigerate for at least 24 hours to allow the flavors to fully develop.
Serve your pickled beets chilled as a side dish, salad topping, or snack. Enjoy!
Notes
Citrus Zing: A splash of orange juice adds a hint of brightness and natural sweetness.
Garlic Lovers' Twist: If you love a little extra punch, toss in a sliced garlic clove for more depth.
Quick Chill Hack: Short on time? Speed up the cooling by placing your jar in an ice bath!