I did try googling this with "Throwing up blood" + taste and assorted other combinations, as well as using vomit and vomiting. I got many hits that mostly related to throwing up blood from the upper GI tract rather than swallowed/digested blood.
What does throwing up blood taste like? Obviously it's digested and mixed with stomach acid, I know it's the black coffee-grounds thing, but my pov is tight on the person doing the puking. Help?