There's also the pectin vs gelatin, and temperature of the test. Some of the precursors of things like Tonkotsu broth (lots of chicken/pig feet) can be fairly

There's also the pectin vs gelatin, and temperature of the test. Some of the precursors of things like Tonkotsu broth (lots of chicken/pig feet) can be fairly firm at 20°c, and nearly solid at 10°.