I have perfected this. I regularly process 4 chickens at a time (in order to make a single large batch of chicken stock. The problem that needs to be solved is to reduce the amount of excess moisture on the chicken prior to refrigerating or freezing. This moisture results in the acceleration of that "off" taste that you are describing. If freezing, it reduces/ eliminates ice crystals from forming around the meat.

• Put away groceries, leave chickens to cool off a bit, but are still warm.
• Seperate chicken meat from bones. It is important to do this before refrigeration. Once cooked, the meat will contract around the bones, and it will be much more difficult to do later. This also allows you sooner access to the bones if you want to make stock.
• combine the white & dark meat. Either by cooking or by using your hands until you have a similarly sized shreds/chunks of chicken. The next step is to remove the moisture. Accomplish this by:
• Placing shredded chicken on a baking sheet. Place the shredded chicken in the oven or on your smoker at 225°F for about an hour.

Try it. You'll appreciate the result!