I find that raw suet just gives me diarrhea, whereas raw marrow is the food of the gods. I can't be sure that the suet I buy is 100% raw(not slightly rendered etc.), but I think it is. All that said, suet lasts forever, especially if it is already dried-out. I used to keep lots of suet out of the fridge for weeks, and all that happened was that the surface became greenish-blue but the inside stayed white.