If you
buy the Granny smith apple from Geoff over at Tastyvapor and ask him to sour it up a little it will get you there. The other way is to just go buy some malic acid and add it to what ever
juice you want and it will sour it up like a Jolly rancher, I am addicted to the stuff, a little goes a real long way though so only ad a little bit at a time. hope that helps ya out add sweetener too