Mechanisms of skin crisping?

Martin_Cheung_21050

Hi everyone,

It seems that there are a variety of methods for crisping up skin. In this context let's assume the skin also has a moderate to substantial amount of fat (I'm thinking pork rinds or duck):

- America's Test Kitchen suggests starting from a cold pan to render out the fat (Lifehacker)

- Chefsteps (e.g. Ultimate roast chicken) hangs the chicken over a period of days to dehydrate the skin

- many people advocate sprinkling salt on the skin to draw out moisture

- add some sort of starch

Obviously the most important step to getting crisp skin is removal of moisture. The way that Kenji from seriouseats explains this is

"It's the combination of these three things—connective tissue breakdown, moisture loss, and firming of proteins—that leads to crisp-but-not-tough skin."

1. Does anyone have additional thoughts on that proposed mechanism?

2. If that's the case, then when we sous vide a protein with the skin, wouldn't the skin absorb much of the moisture and require much more energy and time to crisp the skin? Which I assume would lead to the meat itself being overcooked...

3. Also, what is the role of oil in this? The ultimate roast chicken recipe does not require any oil, for example, but on other forums the use of oil has been suggested.

4. Short of deep frying, what are everyone's favorite technique for crisping skin and rendering fat? Pan or oven? Oil or no oil? Medium heat or scorching hot?

Looking forward to your thoughts!

Martin

Brendan_Lee_56950

Yup, cooking SV makes it very difficult to get a good crisp on poultry skin in particular. I often resort to cooking it separately for that very reason.

Oil, as i understand it, speeds up the transfer of heat making your work more efficient and it also will allow you to heat up areas that you may not be able to reach with say a torch or broiler since the oil will be heated sufficiently to get in all those nooks and crannies.

My standard, for poultry anyway, is to cook the meat SV and then lay the skin out between two silpats on a sheet pan and crisp separately with it's own seasonings. For pork, I will typically chill and scrape any excess gelled liquids and then deep fry.