# Using baking powder to make baked food crispy

The recipe I use for chicken wings achieves a fried texture by dusting the wings with baking powder and then baking at $$220^\circ\pu C$$ ($$425^\circ \pu F$$). The chicken is also dusted with salt and other seasonings, but I assume they're not chemically relevant. What chemical process is going on, here?

I'd assumed it was some kind of reaction between the baking powder and the skin of the chicken, though I had no idea what. Then, one time, there was a stray boneless, skinless chicken thigh in with the wings I bought, and that also became crispy on the outside when cooked this way. I've also heard of people using the same technique on oven fries.

• Check the baking powder to see if it has cornstarch. I suspect that is the secret. – MaxW Apr 14 '16 at 4:24
• @MaxW It does, as does a different brand that I've used in the past. But your question suggests that not all baking powder contains cornstarch, and the recipe doesn't specify baking powder that does contain it. Also, cornstarch is widely and easily available -- why specify baking powder if it's really the cornstarch, which constitutes at most a third of the powder by weight, that's needed? (And what's the chemical process involved in the cornstarch making things crispy?) – David Richerby Apr 14 '16 at 4:37

## 2 Answers

Not exactly an academic source, but a few articles on Serious Eats suggest that baking powder's gas releasing reaction forms small bubbles of protein on the surface that add surface area that can quickly dehydrate (a prerequisite for crispiness) and solidify. It's also a pretty common ingredient in things like batter for fried chicken, where I imagine the expanding bubbles do a similar thing—allow easier removal of water from the batter by increasing the surface area so it can crisp up.

The pH change may also help break down the skin, if applied in advance.

• It's not applied in advance in this case -- toss food in powder, put in baking dish, put in oven -- and it also works on meat with no skin and, allegedly, on potato, which doesn't have nearly as much protein. – David Richerby Apr 14 '16 at 4:48
• The acid could definitely help break down the skin increasing its permeability to water - in other words the reacted skin drys out faster thus gets crispy. – MaxW Apr 14 '16 at 4:51

The Charlie Brown's Thanksgiving episode of Binging with Babish claims that the baking powder "lower[s] the temperature at which the Maillard reaction occurs." Wikipedia doesn't quite back that up but says that the Maillard reaction "is accelerated in an alkaline environment (e.g., lye applied to darken pretzels [...]), as the amino groups ($$\ce{RNH3+ -> RNH2}$$) are deprotonated, hence have an increased nucleophilicity", which amounts to much the same thing.

• Raaaaandomly found the answer to my question, three-and-a-half years later. – David Richerby Sep 18 '19 at 15:03