So far, of all the methods I’ve tried, the best (non-freeze drier) method is to core, de-seed the raw peppers and cut them in half or thirds, crosswise. Add a little Feta and 2-4x as much Queso Fresco, all to taste, plus a little dribble of oil, e.g. peanut oil, neutral flavored oil. A blender or a Vitamix does a much better job at pureeing, than a food processor. Today, I used the Vitamix, low speed & plunger to get stuff going. Then, gradually ran the low speed to max and let it grind everything together for a bit. I switched it to “Hi” for about ten seconds and cut it off.
The sauce came out very creamy with really no noticeable skin bits or grittiness. There was no need to add liquid or crackers. I bet the pepper juice got emulsified with the oil and dairy. So, it largely depends on how you grind the peppers. The Peruvian grinding stone ground up skins to nothing, but a strong blender or Vitamix can do the same. In the hierarchy of best>worst: Vitamix>Blender>Food Processor. Of course, if you like your sauce with more texture, reverse the order!
Shrinkrap, the freeze>food mill is an interesting idea! It might make juice after freezing and thawing, but it might work if the skins stay in the food mill. You would not want to refreeze again, since each time you do that, there’s more water separation. I don’t know; it could be a good idea. One of us should try it! After freezing and thawing, those saltines mentioned in some recipes might help thicken it.
For simple Aji paste, I put the raw, cored, chopped Aji in the Vitamix with a dribble of oil and let it rip. A blender also can work and is the most common tool used in Peru. That puree gets frozen in jars with a little air space and a tight seal. Half-pint mason jars work well. I bet one could put a thin top layer of oil in the jars, before freezing, to cap the puree and prevent freezer burn or oxidation.
Again, onion or garlic can be added, but do not survive well frozen for long periods. You can add these right before serving or for short-term freezing. Myself, I prefer simple, where the peppers really stand out as the dominant flavor.
