Simmer together the vinegar, water, salt, and spice bag, covered, for 10 minutes.
If you prefer, the spices may be left loose in the brine.
Pack the hot eggs in a hot clean quart jar, cover with liquid, and refrigerate for 3 to 4 days before serving. Use a large-enough jar to allow room for the spice bag, if using. Carefully rotate the eggs every day