Why do chicken wings turn chewy if cooled between cookings? I prepared some chicken wings by:


Place chicken wings, raw, in cool oil. 
Heat corn oil to ~180°F, hold at ~180°F for 3 hours (in the oven).
Heat peanut oil in deep fryer to 370°F (as high as the deep fryer goes). Time such that deep fryer is heated by the end of the 3 hours.
Drain now-cooked chicken wings
Deep fry (while still hot) for 4 minutes, flipping half way through.


These came out good. While somewhat dry (but not overly so), they had very tender fall-off-the-bone meat and crunchy skin.

However, for a few of them, I inserted a step 4(b), put in plastic bag and chill in ice bath. I then deep fried them for an extra two minutes. They weren't quite as browned, but more importantly they could have been passed off as chewing gum.

Why did cooling the chicken wings turn them to chewing gum? Is there any way to avoid this (other than not cooling them, of course). It'd be nice to be able to do the time-consuming part in advance.
Your temperature is too high. Go for 78ºC (172F) instead of 82ºC. 3 hours seems a long time for chicken wings. Get a thermometer and take it out when it reaches 78ºC. After cooling, before frying, do you dry the wings? That could be an important step.

Lastly, instead of frying them as is, try panning them with flour or breadcrumbs.

If you're going to fry immediately, aim for 75ºC instead.