I have run into this a few times. I soak dry posole overnight, and then add it to my sweated/sauteed vegetables, add water, and stir it regularly, and it still takes over 4 hours for the kernels to pop. Is there a part of the process I am missing or doing wrong, or could I just be dealing with old posole?
Posole is essentially Nixtamalized Corn, or hominy.
Use a pressure cooker. Try for example this recipe:
http://ljcny.wordpress.com/2011/09/13/chicken-pozole/
where dried hominy is cooked in a pressure cooker.
The pop is a steam explosion, caused by rapid heating of the kernels' interiors.
Put the well-soaked kernels into boiling water, only enough at a time to avoid taking the pot off the boil. Add them carefully and watch them pop.
A pressure cookers heat is too gradual and heats the kernels relatively evenly.
10 minutes in pressure cooker from the time it starts to boil, according to a table I found on cooking grains in a pressure cooker
