How polite are you?

I have a friend who makes every Christmas several Christmas puddings and she always gives me one. Unfortunately, her puddings are very dense and dark and claggy but she waxes lyrical about them. My predicament - I make a lighter pudding which my family love with Christmas lunch - and prefer that type of pudding. For several years now I have thanked her and left it in the cupboard, knowing it would never get eaten. It is then disposed of by Easter. How honest should you be with someone if they give you something they love and you just don't get it? She is incredibly kind, lovely, and delightful. I feel that it would hurt her if I told her the truth. And so we go another year, another pudding. I suppose I could say something like: I have digestive issues. What's to do?