Wash the chiles and chop off their stems. If you like your sauce less hot, remove the seeds and membranes and discard.
Work the next step in 2 batches so you don't overload the food processor.
Add the chiles, garlic, salt to the food processor. Process for 2 minutes until very liquid. The mixture should have consistency of a smoothie and appear a bit foamy on top.
Scrape the sauce into a very clean 1-quart (or larger) glass jar. Don't use plastic. Cover the top of jar with paper towel and secure with rubber band. This prevents bugs from entering and allows sauce to breathe.
Place jar in cool, dark place for 2-4 days. The liquid will settle at bottom, and the thicker sauce will rise to top. The top should be bubbly - which is a sign of fermentation. Taste, and let sit for a few more days if desired. I prefer 7 days of fermentation.
If mold grows, remove the mold with a small spoon - and then proceed to the next step (basically, don't eat the mold directly, but the sauce should be okay).
Pour the sauce through a fine-mesh sieve. Now you'll have the thinner "Tabasco" like vinegary hot sauce and the thicker hot chile sauce. To each, add 3 tablespoons of vinegar and stir well.
You may like to run the thicker sauce through the blender for a finer, thinner consistency.
Store each tightly sealed in refrigerator. The thicker hot sriracha sauce will keep for up to 4 months. The thinner vinegar hot sauce will keep indefinitely.