No, do not stuff with ECA mixed in and let sit until the next day. You need to smoke right after adding the ECA.
The reason is if the ECA has time to leak into the uncooked meat it will turn it white an grainy in texture. Basically it will ruin whatever it is you are making. The correct was is to mix your spices and let the meat sit over night (if you want to let it "meld"), then add the ECA, stuff and move to the smoker (add the ECA minutes before cooking/smoking). Also do not use a grinder to perform the stuffing as it will break open the ECA capsules and release the CA way too soon also affecting the meat in a negative way. Use a manual stuffer,
jerky gun, or similar to stuff casings when using ECA (or you can make casing less sticks as well).
ECA is designed to be activated at a certain temp in the smoking/cooking process. Most are little balls of citric acid that are encapsulated with a fat that will melt at a fairly low temp. The fat will melt around the 140* mark releasing the CA into the product. By that temp, the meat should be set and mostly cooked so the CA will add twang without damaging the meat texture and mouth feel.
When I use ECA in sticks I mix the ground meat with all the spices and let it set overnight in the fridge to give the spices and flavorings a little time to meld and blend with the meat. Then the next day (or even the day after that), I mix in the ECA with a little ice cold water by hand before placing the meat into my stuffer. After stuffing the stick casings, it's straight onto the smoker to start the cooking process. I use a PID controlled electric element in a 18.5"
WSM body and raise the temp in stages ranging from 130* to 170* at the finish. Usually takes about 6 to 7 hours for a batch. This will vary depending on your smoker and the method of smoking/cooking you choose.
