In a medium sauce-pan, combine water, distilled white vinegar, and Worcestershire sauce. Then add your dark brown sugar and and molasses and ensure they're dissolved and well combined.
In a separate bowl combine 1 tbsp of corn starch and 1/2 tbsp of water to create a slurry and then add to sauce.
Then add tomato paste and ensure well combined.
Then add the rest of your dry ingredients and whisk together thoroughly.
Set your burner to medium heat and get your sauce to a slight boil. Once at a slight boil, lower the heat to low/simmer.
Allow the sauce to simmer for 20 minutes or until your desired consistency. Note: The sauce is suppose to be slightly thin.
Once at your consistency, take off the heat and allow to cool. Once cooled, transfer to a small mason jar or similar non-reactive container.
Store in your refrigerator for 1-2 weeks.
Notes
If you want some smoke flavor, add 1/2 tablespoon of liquid smoke.