The traditional technique for oil extraction is to grind the roasted seeds to paste, with a little water, in a stone rotary quern. The paste is then squeezed by hand to extract the oil. The extracted paste is still oil-rich and is used as animal feed. Oil produced this way can be stored and used for 3–6 months, and will be produced as needed in a family, from a store of the kernels, which will keep for 20 years unopened. Dry-pressing is becoming increasingly important for oil produced for sale, as this method allows for faster extraction, and the oil produced can be used for 12–18 months after extraction.