The Plunderer's Ring is a MUST as it not only raise the chance of getting Black Pepper, but also other items at the same time. To put it simple, keep pushing the Manipulative ability and rush between the 2 large rooms in the Underground Sorcery Lab (in all, those are the 2 large rooms separated by the corridor with a bunch of monkey in green.. Black Pepper is a food ingredient in Bloodstained: Ritual of the Night. Underground Sorcery Lab: Random drop from blue chests. Black Pepper is one of a few ingredients that can only be found in blue chests, spawning in the Underground Sorcery Lab. One such chest is next to the Lab's entrance, with another chest two rooms to the left (see Comprehensive Map). Exiting and reentering the Lab will.
The black pepper is a chest item in a place after the tower. I can be more specific if you don't mind spoilers.. For Bloodstained: Ritual of the Night on the PlayStation 4, a GameFAQs message board topic titled "black pepper".