I've made this sauce twice now using brisket drippings from the pan. This sauce is simple AND great. Very good taste while not overpowering the meat.
When I pull the brisket to finish in foil/hold in cooler I will collect the fat from the pan and put it in a cup.
I put the fat into a tall/thin cup and store in the freezer for about 20 minutes. By that time a good amount of the fat has separated and I remove the fat "disc" from the top of the cup. I will then put the cup back into the freezer for 10-15 minutes to do a second collecting of fat. By this time I feel most of the fat has been removed from the drippings. I will add 1/4 to 1/2 C of this to the original recipe, depending on taste.
I will make the sauce according to the recipe then add honey/molasses to taste. I like a sweet sauce. Awesome stuff! I feel the drippings add a smokier/fuller flavor to the sauce.
The drippings will turn into a jelly if left in the fridge overnight. To return to liquid it takes a small amount of heat.
I have a question concerning making the sauce from pan drippings from pork butt.
Should this work the same as when making the sauce using the brisket pan drippings? I would assume it would work exactly the same.
I'm usually worried about the drippings being contaminated, especially if they have been sitting in the pan for 8+ hours. I assume that the temperature in the smoker will keep the drippings hot enough to prevent any contamination, but I am not 100% sure.
Also, simmering the sauce for at least 20 minutes, I assume that any bacteria will be killed by the heat. I just want to be safe.
The reason I prefer to use pan drippings over juice collected in the foil while holding is simply a time issue. I like to have the sauce prepared before the final rush of getting the meal ready.