Prepare your mise en place.
Combine the water and vinegar with the onions, carrots, parsley stems, thyme sprigs, and bay leaves in a stockpot over medium–high heat. Add the salt. Bring to a boil and then lower the heat to maintain a gentle simmer. Cook for 20 minutes. Add the peppercorns and continue to simmer for another 10 minutes. Remove from the heat and allow to cool. Strain