Spicy Pickled Beets Recipe

4 lbs. beets, cooked
3 cups thinly sliced onions, about 3 medium
2 1/2 cups cider vinegar
1 1/2 cups water
1 tsp. salt
2 cups sugar
1 tbsp. mustard seed
1 tsp. whole allspice
1 tsp. whole cloves
3 sticks cinnamon, broken

To cook beets: Wash and drain beets. Leave 2 inches of stems and the tap roots. Cover with boiling water and cook until tender. Remove peel. Combine remaining ingredients in a large sauce pot. Bring to a boil. Reduce heat and simmer 5 minutes. Add beets and cook until heated. Remove cinnamon sticks. Pack hot beets into hot jars, leaving 1/4-inch head space. Pour hot pickling liquid over beets, leaving 1/4-inch head space. Remove air bubbles. Adjust caps. Process 30 minutes in a boiling water bath.