Ingredients

2 celery stalks, halved 

2 medium carrots, halved 

1 small onion, halved 

10 cups water

Preparation

Combine all the ingredients in a large stockpot. Bring to a boil. Reduce heat, and simmer, uncovered, for 30 minutes. Strain and discard vegetables. Let cool, and refrigerate for up to 4 days.