Chicken Stock From Rotisserie Chicken (That Gels)

I recommend 12 hours for stock with a richer mouthfeel and deeper, more nuanced flavors, but 8 hours at minimum and 20 hours max.

When testing this recipe, I consistently tasted the stock every hour to monitor the flavor development. No real flavor developed until hour 3. From hours 3-7, the flavor had not further dramatically developed, but at the 8-hour mark there was a noticeable difference in flavor. I was able to clearly taste the flavor of all the herbs and vegetables I added, and the stock had a moderate chicken flavor.

There was another jump in flavor quality at the 12-hour mark. After 12 hours, the stock tasted heavily of chicken, had a richer mouthfeel, and the sweeter notes of added aromatics came through even more.

After 20 hours, I found that the chicken flavor did not have any additional depth, but aromatics and vegetables continued to deepen in flavor, with some notes becoming bitter.

A gelatinous chicken stock is a sign of a job well done! As the chicken stock simmers, the collagen in the bones breaks down and is pulled into liquid. This collagen resolidifies into a jello-like consistency once the chicken stock is refrigerated.

Not as long as you keep the heat low. Since the rotisserie chicken is already cooked, it produces much less (if any) white foam as it simmers compared to a chicken stock started with raw chicken/bones. If you are seeing foam collecting on top of your chicken stock while it cooks, you should skim it, but this is likely an indication that your heat is too high and should be lowered.
The only thing you will likely have to remove is any fat that renders, and this is totally up to personal preference. I like to keep the chicken fat since it doesn't render in copious amounts and it makes the chicken stock richer.

You can, but as the stock simmers, it will produce more white froth, requiring more maintenance. If you're starting with raw chicken/bones, I recommend roasting them in the oven until browned and cooked through before adding them to a stockpot to simmer. This will give you a chicken stock that has a more complex flavor and is less needy since you won't have to skim it as often.

A gentle simmer has a slow but steady bubbling with small bubbles. I can achieve this at "low" on my stove.

Chicken stock has a deeper flavor since it's usually simmered for hours, while a broth is lighter in both flavor and color. You can use chicken stock in almost any recipe that calls for chicken broth.