A method for removing contaminants such as pesticides and fungicides from cannabinoid extracts. Cannabinoid extracts containing contaminants may be dissolved in a water and ethanol solution, and then cooled to allow water-soluble contaminants to settle out of the mixture. The water and ethanol may then be removed via evaporation or distillation, leaving purified cannabinoids without contaminants. Contaminant removal may be incorporated into a method for producing a blended extract of cannabinoids and terpenes, which extracts terpenes using supercritical CO2, and extracts a cannabinoid concentrate from the residual material using a cold ethanol flush followed by distillation and then by contaminant removal; the CO2-extracted terpenes are then added back to the purified cannabinoid concentrate in a final blending step. Blending terpenes at the end of extraction may enhance the flavor and effectiveness of the purified cannabinoid concentrate.