SUPER-CRISP
ROASTED POTATOES
How often do you get roasted potatoes that look like
they’re going to be awesomely crisp only to find that
rather than crispness, all you’ve got is a papery (or
worse, leathery) skin on the exterior?
Roasting potatoes is not quite as easy as roasting most
other vegetables. See, with roast potatoes, we’ve got a
different set of goals than when, say, roasting Brussels
sprouts. First off, we want the potatoes to be cooked
through all the way to the center. Fluffy and moist is what
we’re after. Second, we want the exterior to be extremely
crisp. We’re talking crisper-than-a-French-fry crisp.
Simply toss a potato coated with a bit of oil in the oven,
and what you end up with is a potato with a paper-thin
sheath of crispness around its exterior that very rapidly
softens and turns leathery as internal moisture seeps
through it.
So, what makes a potato crisp? The answer is building
up a dehydrated layer of gelatinized starch on the
exterior of the spud, much like when you fry a French fry
(see here). To do this, you’ve got to parcook them,
allowing their starches to soften and expand, and then
recrystallize by cooling them a bit.