If making your hot sauce shelf stable (a pH of 3.8 or lower) is important to you, use a ratio of 4 ounces (½ cup) vinegar for every 10 ounces of chopped peppers, onions, and garlic combined. Following this recipe, you should have a combined 15 ounces of peppers, onions, and garlic, which is why the recipe calls for 6 ounces (¾ cup) vinegar. You can check the pH of your finished hot sauce by using a pH testing kit.