Bad olive oil. THAT'S IT!! I bought this juice when I first started vaping, and really wanted it to be good. This stuff is the NASTIEST stuff I've tried. I had to brush my teeth, my tongue, and use mouthwash to try to get that rancid taste out. The atty was a goner. No amount of cleaning would get that horrid taste to go away. I really liked a few of their juices, but this juice literally left such a bad taste in my mouth, this is one vendor that I won't be ordering from again.