Pollo Campero facilities receive their dry mix from a centralized facility. The chicken (from Tyson) may be pre-marinaded or pre-brined for a fixed amount of time and then fed into a rotating drum at the same time that the dry mix is fed in. The rotating mechanism thoroughly coats the chicken pieces. These are then fried under pressure. This results in a thin, but very crispy crust and is really delicious. My guess is that wheat flour, rice flour, corn flour and some other type are blended into a final dry mix that results in the distinctive Pollo Campero crust.
A few years ago, when Pollo Campero first came to Houston, I found that I couldn't eat their chicken because it was painfully salty. With the introduction of their newer Latin Fusions locations, I've noticed that the chicken is not as salty. It is one of my favorite places to eat. Especially the Washington Avenue location when Daniel is on shift for managing. With a side of quinoa / black bean salad and a second side of cucumber / tomato salad, I am a happy diner.
Update July 10, 2013 to the above: I had come across a sample of the dry mix that they use. A pinch of the mix on the tongue and I experienced garlic powder, salt, cumin, msg, cayenne. Also it dissolved really quickly and that made me wonder: potato flour? You see, I did a dissolve on the tongue test with rice flour, Wondra, AP flour, tapioca, potato flour and corn flour. The potato flour came closest. But, when I did some further experimentation with different dry mix coatings and deep frying, I couldn't get close to the thin and crispy crust. But, I was using boneless and skinless chicken breasts and it may be that for this to work you really have to have the chicken skin.
"I made some fried
chicken experiments last night using potato flour, then Wondra, then flour and
corn starch. The flour and corn starch was the most dry and meh of this batch
of experiments. Pure tapioca starch resulted in a very light color crust. If
had a certain crackle to it but wasn’t pleasant. I tried some slurries with
buttermilk and with ice water. Abby liked the slurry the best. It was the
darkest of the batch. I decided that for Pollo Campero to work, you really need
to have the skin. The closest in texture was the potato flour with lots of
cayenne, black pepper and garlic powder. And I made a note to go for a wheat flour and potato flour blend as one potential solution."