[Dooku is encouraged that Baelish seems intrigued. Not that squeamishness had ever been much of a risk with this one, but some politicians might have found dabbling with ghouls to be too risky from a publicity standpoint...]

There is no requirement that I am aware of. I imagine that like any meat, it is best when not served rotten. Kaneki himself would be able to tell you more- I told him I would contact you to resolve this unfortunate issue.