Thanks to Martha Stewart for this recipe.
Vegan Worcestershire Sauce
2 cups apple-cider vinegar
1/2 cup soy sauce
1/4 cup light-brown sugar
1 teaspoon ground ginger
1 teaspoon ground yellow mustard seed or dry mustard
1 teaspoon onion powder
1 clove garlic, crushed
1/2 teaspoon ground cinnamon
1/2 teaspoon freshly ground black pepper
Place all ingredients in a medium saucepan.
Bring to a boil over medium-high heat; reduce heat to a simmer and cook until liquid is reduced by half, about 20 minutes.
Strain through a fine-mesh sieve and let cool completely before using.
Worcestershire sauce may be stored in an airtight container, refrigerated, for up to 3 months.