From The Grey House:
Vincent sipped from the goblet of blood, wishing it were fresh. Fresh blood would take the edge off his anger at Edwin. The blood used for his parties were taken from willing humans and stored in a small refrigerator in his office. The vampires who drank the stored blood couldn’t receive sustenance from it, but they could still enjoy the taste. It helped relieve the fact that there were no human guests allowed in this part of the club for feeding purposes. His rules. Vincent wanted to keep his fellow vampires from killing anyone in the club. It was bad for business. Half the wait staff was human, but they were off limits. Joseph taught them how to stop vampires and other monsters before letting them work in the private room.
