The ethanol can be acidified with any non-poisonous acid. Preferred acids are hydrochloric acid, phosphoric acid, and organic and natural acids for example tartaric acid and citric acid. Hydrochloric acid causes an extract having a desirable attribute purple colour. EP2174557 discloses a food items comprising at least thirty mass % https://cocoashell18739.blogs100.com/34093399/cocoa-shell-for-dummies