A process in which cannabis is placed in alcohol to extract the cannabinoids from the plant. After the plant is allowed to soak in warm (but not boiling) alcohol for 10 - 20 minutes, it is strained through a coffee filter until it is clear. One of the best alcohol products to use is isopropyl alcohol. The product is then boiled, with or without added pressure, to completely remove any and all alcohol. It is very important to make sure that all alcohol is removed, as isopropyl alcohol can cause blindness if ingested. What remains is hash oil containing around 90% of the cannabinoids from the plant. The longer the extraction, the more oily the product.