Congealed blood

Congealed blood is an item that will be dropped by monsters in Morytania including ghouls and ravenous ghouls. It will be added as a drop ahead of the release of River of Blood and it will tie in with the blood essence related reward from the quest.

It will be presumable that it's use will be in Haelchemy which was mentioned as a reward from the river of blood quest, a type of magic/alchemy that focuses on blood as a fuel.