Rosin refers to an extraction process that utilizes a combination of heat and pressure to nearly instantaneously squeeze resinous sap from your initial starting material. The term “rosin” originated as a method of making a product used to lubricate violin bows. With cannabis, this method is incredibly versatile in that it can either be used with flowers or to clean up hash and kief into a full-melt hash oil. The result is a translucent, sappy, and sometimes shatter-like product. If executed correctly, rosin can rival the flavor, potency, and yield of other solvent-based extraction products.