Eating and drinking anything but blood is disgusting to ALL vampires. Anything you ingest will not only taste bad, but will also be immediately vomitted back up. Even those with the Eat Food merit, which allows you to hold down without the spend and enjoy it to a point, will have to puke up the food or drink they consume eventually.
Anyone else attempting to eat or drink anything that is not blood or that contains blood will have to spend a blood point or immediately be faced with having to puke, right then, right there.
Most vampires do not think the effort is worth the blood because even if you do spend, it tastes nasty and disgusting. Like ashes.
Why is this? You can find reference to it in the Book of Nod, Caine's supposed words to his childer:
"And then, through dread Uriel God Almighty cursed me, saying. 'Then, for as long as you walk this earth, you and your children will cling to / Darkness / You will drink only blood / You will eat only ashes / You will be always as you were at death, / Never dying, living on. / You will walk forever in Darkness, all you touch will crumble into nothing, / until the last days.' "