Downriver
eXtreme
I'm not sure we're talking about much more than pureed pickled jalapenos, but the boss ingredient IS peppers, and that's awesome. When I look at your ingredients, the only thing that jumps out to me that can be bitter is your "Chipotle spice". Using "bad" smoke can definitely make things bitter, and since you "...have smoked, dried and ground to make the chipotle spice", I suspect it may be the source. I'd taste it straight up and see if you taste "bitter". Also, taste it after you mix the spice with vinegar. There could be a reaction between vinegar and the smoked chipolte creating bitter notes.
Just my 2c. Good luck with it going forward.
Just my 2c. Good luck with it going forward.