What to Do with Shea Nuts (Karité, Nku, Bambuk)

Processing

The Green pulp exterior is removed. One method is to bury the fruit in the ground so that the pulp ferments and falls off. This takes 12 days or more. The nuts are parboiled or sun dried and then smoked for 3 to 4 days. The dried nuts can then be stored for long periods without significant losses. Decortication is done by crushing the outer shell to remove kernels. Shea nuts are mainly exported as smoked kernels. The kernels will be further dried before any additional processing is carried out.

Shea nut butter

Traditionally wet processing by hand is a slow and laborious process that uses large quantities of wood for roasting. The kernels are roasted in a pot over a fire to approximately 100°C and then pounded in a mortar to produce a course paste. This is then ground between two stones to produce a smooth paste. The paste and water are mixed in a pot where the butter rises to the top. The butter can then be removed and washed repeatedly with warm water until clean. The remaining water is remove by heating. Impurities settle out and the butter can be left to cool and solidify. With the traditional technique, the fat obtained is between 25 and 40% of the dry kernel weight.

The introduction of equipment can improve upon traditional methods of production by reducing the effort and time involved and by increasing the yield. Instead of pounding by hand a mill can be used, Oil can be extracted using a mechanical or hydraulic press. Manually turned roasters can be used rather than a traditional pot. A very important consideration is the minimum throughput required to run the equipment profitably, including the initial cost, management of the equipment and maintenance.

Shea butter press

The fat is squeezed out of the heated shea-powder under high pressure. For a high amount of fat, a press capable of at 125bar pressure is required. The fat must then be cleared of all residues by bringing it to the boil together with okra, lemon juice and water. To increase the output, the process can be repeated. The resulting press cake is excellent for use as fuel for ovens and reduces the fuelwood demand. The amount of fat derived is determined by the condition of the shea nut. The yield will be greater if the harvest carefully stored and preserved. Complete inactivation of enzymes will prevent the formation of free fat acids. The heating of the powder to between 100° and 120° Centigrade is not difficult but the unassisted use of the press needs longer to learn. In order to get a maximum pressure of 125 bar a lot of force is required by the user.

Food

Used as baking fat and to substitute cocoa butter to make chocolate and other products.

Cosmetics

Shea butter is used as a base for cosmetics, skincare products moisturising cream anti ageing treatments. It also has anti inflammation properties.

Soapmaking from Shea

The cake left after the second pressing can be burned to produce potash for soapmaking or for fertiliser.