Normally I take the easy route and buy preshredded coleslaw mix in a bag. Since they were practically giving away cabbage at the market last week I bought a head to make into coleslaw. I chopped the cabbage and used the same dressing I always use (yes, it is also premade) but this is the most horrible tasting coleslaw ever! It seems to get more and more bitter the longer it sits. What did I do wrong and can I save what I have?