Crispy Sweet Potato Fries
My wife and I have spent the better part of 3 afternoons trying to figure out how to make savory sweet potato fries that are CRISPY.
We've used vegitable oil, canola oil, peanut oil. We've tried double fry methods at multiple temperatures/times. We've tried all sorts of coatings from flour w/ cayanne, salt, brown suger, cinnamon to just broan sugard (and one really terrible last ditch effort with corn starch). The flavor's range from absolutely putrid to very good -- but we've yet to get a crispy exterier.
Does anyone have a method that works well?
We're really trying to recreate the Father's Office fries from Los Angeles as we've moved away and can't afford plane tickets to support our frequent cravings. So if that's helpful information to anyone -- there it is.
Any input is appreciated!
A thin layer of starch is helpful in getting potatoes crispy-- white potatoes generally have enough built-in starch that they can (in principle) get crispy, but sweet potatoes don't. Contrary to the draining idea above (which does make sense), I actually soak the sweet potatoes in salted water for a short while and then toss them with a small amount of (powdered) potato starch to lightly coat them. I usually do this by shaking in a paper bag, it seems to distribute the starch well on the surface of the fries and lets the excess water and starch go their separate ways... This sounds not too different from your corn starch misadventure, though-- what went wrong with that?
When a potato is dropped into a deep fryer the first thing that happens is that the water in the potato forms steam and the steam creates a surface barrier on the outside of the potato which interferes with the browning/crisping process. I'd say you need to eliminate some of the water in the potato (perhaps a short visit to the oven prior to the deep fryer) and that you might want to try cooking them in the deep fryer at about 350 degrees until tender then remove them, allow them to cool, and drop them back in a second time at 375 degrees.