This recipe makes a medium-spicy hot sauce. For a spicier sauce, include all the Fresno chile seeds. For a milder sauce, remove the seeds from the chiles. We recommend wearing rubber gloves when handling the chiles. If you can't find Fresno chiles, you can substitute red jalapeño chiles. The leftover brine can be used in marinades, dressings, cocktails, and on its own as a condiment to spice up soups or braised greens.

Whisk 2 cups water and 2 tablespoons salt together in 4-cup liquid measuring cup until salt is dissolved. Remove seeds from half of Fresnos. Place Fresnos and bell pepper in 1-quart Mason jar, pressing peppers firmly into bottom of jar.

Pour brine into jar with peppers, making sure liquid covers peppers. Fill 1-quart zipper-lock bag with ⅓ cup water, press out air, and seal bag. Place bag of water on top of peppers in jar to keep submerged in brine. Affix jar lid but only partially tighten, leaving lid loose enough to allow air to escape as mixture ferments.

Let jar sit at room temperature away from direct sunlight for 4 days. Check container daily, skimming residue from surface and ensuring that peppers remain submerged. (After 2 or 3 days, brine will become cloudy and bubbles will rise to surface when jar is moved.)

Drain peppers in fine-mesh strainer, reserving brine for another use, if desired. Process peppers, sugar, and salt in food processor until coarsely pureed, about 1 minute, scraping down sides of bowl as needed. Add oil and pulse until combined, about 2 pulses. Refrigerate hot sauce in airtight container until ready to use. (Hot sauce can be refrigerated for up to 3 months.)

Preservation Through Fermentation