need help with my homemade veggie chilli

Ok, just made a big pot ful of home made veggie chilli, using passata, tabasco sauce, chilli flakes and lots of veggies... tastes great, except i feel like its missing something, im thinking it should be a little sweeter as the tomatoes in the passata seem to be bitter, what should i add? im thinking apple cider vinegar, or white wine vinegar... anyone help me?