Duck leg ragu

[jmax]

I've come across a number of duck leg ragu recipes and have a question. A number of them say to cook the legs in the tomato sauce with skin on and to remove the skin and bones when done. What does the skin add? I will skim the fat off the top of the sauce before I serve it - so it is not adding fat.

[Louise]

The skin and bones both add gelatin, which is good for the 'body' or texture of the sauce. Flavor as well, especially if you are browning the duck before the braising stage.

[hannaone]

The skin adds a lot of flavor.

[Hungry Celeste]

It also adds some gelatin/thickening power to the sauce. Skin is collagen-rich, and that collagen unwinds and cooks into gelatin, giving the sauce a more lush mouthfeel.