First, prep your veggies. (Pro tip: Use gloves when handling the peppers to avoid burning your hands and eyes. I learned the hard way. Argh!)
I’ve found that removing the seeds and most of the ribs from the jalapeno peppers produces a sauce of moderate heat, which is my personal preference. If you like to breathe fire and have a Teflon gastrointestinal tract (hello, Charles Mayfield), feel free to keep the ribs and seeds, and/or use hotter peppers (like serranos or even Lumbre peppers).
Throw everything into a high-speed blender (like a Vitamix or Blendtec) or a turbocharged food processor.
A regular food processor will also work — but you’ll want to cut the peppers and garlic into smaller pieces, and blitz the ingredients longer. Otherwise, your sauce may end up on the chunky side. We tested a batch using a weak little mini-prep, and the resulting sriracha was noticeably thicker (but still insanely flavorful).
Purée until smooth.
Don’t worry about the froth on top — it’ll cook off later.
Pour the purée into a medium saucepan and bring to a boil over high heat.
As soon as it boils, reduce the heat to low and maintain a simmer for 5 to 10 minutes, stirring occasionally.
By cooking the sauce, we concentrate and deepen the flavors, and cut the sharpness of the raw garlic.
Once the foam subsides, the sauce should be a vibrant red color, and you shouldn’t be able to detect any raw vegetable smell.
Taste and adjust for seasoning if necessary.
Transfer the sriracha to a jar (or three) and allow the sauce to cool. You can keep it in the fridge for up to a week.