Sunny Isle Extra Dark Jamaican Black Castor Oil, 100% pure Back Castor oil with the most ash content. Sunny Isle Black Castor oil is processed in the traditional Jamaican way. The organic seeds are manually roasted and ground. It is then boiled to extract the 100% pure oil. Because the coupons are roasted longer, more ash is released, the higher the ash content, the more effective the oil. This oil ensures stronger, fuller and firmer hair growth!