A Saveur recipe, modified by Merl and sent by Sharon.

1 lb. mixed medium-to-hot fresh chiles, stemmed and seeded if very hot (Merl recommends 1/2 jalapeños and 1/2 serranos; Saveur recommends red peppers like fresno, holland, or cayenne)
3 garlic cloves, peeled
1.5 tbsp. or more kosher salt, to taste
1/2 cup or more distilled white vinegar to taste

1. Rinse the chiles in a colander under hot running water; pat dry. Process chiles, garlic, and salt in a food processor, stopping occasionally to scrape down the sides of the bowl with a rubber spatula, until finely chopped, about 1 minute. If you need liquid in your food processor to get traction with the blades, add about 1/2 cup liquid (Merl added orange juice; perhaps vinegar or water would work just as well?).

2. Transfer the chile mixture to a glass jar. Cover and let sit in a cool place (such as your fridge) to ripen for 2 days, without stirring.

3. Uncover and stir in the vinegar. Cover and let sit in a cool place for 5 days to let age and allow the flavors to meld.

4. Tweak flavors to taste by adding more vinegar and/or salt.

5a. To make a blended pepper-style hot sauce, eat as is (and it will be really hot!!).

5b. To make a Tabasco-style hot sauce: Set a mesh strainer over a bowl. Pour the chile mixture into the strainer and press it through the mesh screen with the back of a spoon. Discard solids. Pour sauce into a glass bottle with a tight-fitting lid. Refrigerate for up to 6 months. Shake before each use.

An alternative hot sauce recipe from the Foggy Bottom Farmer's Market is also posted as a PDF.