Chop garlic scapes and add to fermentation vessel. De-stem jalapeno peppers and quarter or chop and add to fermentation vessel. Chop green onions and add to fermentation vessel.
Add salt and water to a small pot and heat, stirring until salt dissolves. Let the saltwater brine cool, then add to the fermentation vessel.
Place the weight in the vessel, ensuring all vegetables are below the water line. Close with an airlock. Place on a plate (in case it bubbles over) and put in a cool, dark, dry place to ferment.
After a few days, you should start to see bubbles in the ferment. This means it's working.
After 7 days, taste a scape to test for readiness. (There's no real measure of when it's ready, you go by taste and preference.) Ferment should be done in 7-10 days.
Strain vegetables, reserving the brine.
Add vegetables to a blender, vinegar, and ⅔ cup of the reserved brine. Blend until smooth.
If you prefer smooth sauce:Strain though a strainer or cheesecloth, then store remaining liquid in a bottle or jar in the fridge.If you prefer chunky sauce:Transfer blender contents to a bottle or jar and store in the fridge.