//ooc; I don’t know enough about the science with blood, but in my opinion, yes, humans taste different to vampires based at least partially on that person’s diet, and I headcanon that they do things to affect the flavor when they feel like going to the effort, like getting their victims drunk or aroused or terrified or whatever.

[X Someone has a sweet tooth fang.]

If placed before him, yes, I think Lestat would have to have previously tasted that blood if he’s trying to identify it. And it would have to be somewhat fresh, I would think dead or dried blood loses a lot of its flavor (and it’s pretty unappealing to vampires anyway).

With mortals, Ricean vampires are supposed to have perfect memories, and I do think Lestat has his favorite types of mortals and/or ways to flavor them with specific drinks/foods/ or provoking them into specific emotions, and he has favorite mortals he visits repeatedly for Little Drinks (unbeknownst to them, probably).

Werewolves might have something of the wolf taste in them and that would be noticeable to a vampire as odd for a human. So yes, I think Lestat could tell if someone was a werewolf.

With witches, I think they would fall under the “if Lestat has tasted their blood before, he can identify them,” but I don’t think there is anything specific to witch blood that would let him know it’s a witch, since witches are mortals who practice a religion. I don’t know enough about witches to know if it changes their blood physically, but if it does, vampires would probably notice.