I recently bought a jar of oil-cured black olives. They have a bitter aftertaste that I haven't experienced with other types. Is this normal? Or did I just get a bad batch? Should they be processed in some way before use?

So far I've tried eating them right out of the jar, and used them on pizza (they got rather dry and crispy). Any suggestions on ways to use them that might minimize the bitterness?

Thanks, all!