A means for the extraction and crystallization of quassinoids such as quassin and neoquassin from natural sources containing these compounds, using compounds that are Generally Recognized As Safe by the U.S. Food and Drug Administration is provided. In particular, a means for extraction that does not require use of lead acetate, chloroform, methanol, or diethyl ether is provided. The process includes a means of removing non-polar and very polar substances from an extracted residue to enhance crystallization of quassinoids from the residue.