Chicken Stock Variations

Not size and shape per se, but they could be indirectly related. Gelatin is the result of the conversion of collagen (connective tissue) by heat, a process that begins around 140F and is most efficient close to boiling. So, time and temperature are the first two factors. The resulting thickness depends on dilution and temperature. So, weight of chicken carcass divided by quantity of water which must cool to gel.

I would think that the size and shape may be a factor for the scum or the jelly appearing. Less space for it to simmer in the crockpot. I would just skim and proceed. The best thing is that making home-made stocks and broth in the slow cooker is very forgiving with time (high or low setting). I have a newer slow cooker that I can control the heat to an extent. As you know, slow-cookers NEVER boil, and the steady simmer really makes it delicious as a conventional stove-top preparation.

there is a difference in size and shape. i don't mind the difference in how it comes out, i'm just wondering why that happens. one of the cookers is tall and circular (think typical crockpot) the other is shallower and oval shaped. does that really make the difference i am seeing?

Is there a difference in the size capacity of the two slow cookers. I use my slow cooker to make stocks year-round ensuring I always have some on hand with excellent results. Also, are you using the same recipe, chicken size, and temperature (high or low) that may change the results? FWIW, I use a low setting.

First of all the jelly part is a good thing. Second no two slow cookers are created equal. But third, a slow cooker is not the best vehicle for chicken stock anyway. It's better to use a stock pot over a gas range where you can control the simmer. A stock should never boil, just bubble a tiny bit. For chicken this will need to simmer for three to four hours with your bouquet and aromatics. Strain (preferably through a chinois) and refrigerate overnight.