J-Hawksmoke
My opinion is this...ALWAYS, ALWAYS, use a rub on your pork shoulder! As
Earl D mentioned in his reply, coating the meat with yellow mustard is a good idea as it helps the rub to adhere to the meat better. The mustard flavor will be cooked away during the smoking process and will develop into a beautiful dark brown "bark" by the time it's done. As a rule, I will apply the mustard and rub the day before I plan to smoke, then wrap it tightly in plastic wrap and then in HD foil and leave it in the fridge for at least 8 hours or longer to marinate.
There are many different rub recipes available either commercially or right from this site. I prefer to make my own and have tried most of the recipes that I found in this forum, some I've used exactly as posted and others I have made minor modifications to suit my own tastes...they are all good, so I recommend that you experiment with them until you find "your" perfect combination. If you are looking for a sure thing though, I suggest that you give
Jeff's Naked Rib Rub a try. I recently purchased it through the site and have gotten exactly the rave reviews that Jeff promises. (Please note that I do not know Jeff personally, nor have I ever met him outside of this forum, I am simply passing on my own personal opinion about a truly good recipe).
Well, I certainly hope this helps,
J-Hawk, and welcome to the group. There is much to learn here, so check in often. Good Luck and keep on smokin'!
Cheers,
Brian