how to process cassava into gari

Gari is a creamy-white, granular flour with a slightly fermented flavor and a slightly sour taste made from fermented, gelatinized fresh cassava tubers. Gari is widely known in Nigeria and other West African countries.

Process flow chart for gariIt is commonly consumed either by being soaked in cold water with sugar, coconut, roasted groundnuts, dry fish, or boiled cowpea as complements or as a paste made with hot water and eaten with vegetable sauce. When properly stored, it has a shelf-life of six months or more.

Principle of preservation and processing of cassava

Cassava is fermented to remove cyanide and produce the desirable flavors. It is then roasted to destroy enzymes and microorganisms, to drive off cyanide gas, and to dry the product. Preservation is achieved by heating during roasting. A low moisture content inhibits recontamination by bacteria. Packaging is needed, especially in areas of high humidity, to retain the low moisture content.

Raw material

Fresh cassava should be free from microbial or insect damage and without serious bruising or cuts. It should be processed within two days of harvest to prevent deterioration and loss of quality in gari.

Hygiene

Fresh cassava is a moist, low-acid food that is susceptible to bacterial and fungal growth. Hygienic practices, especially in the early stages of processing, should therefore ensure minimal contamination. All waste materials from the process should be removed from the site as they are produced to avoid the risk of cross-contamination.

Process control

Washing should be carried out thoroughly to avoid contamination of the final product with peel, sand, and so on.

Fermentation must be properly controlled, as too short a period will result in incomplete detoxification and a bland product. Too long a period will give the product a strong sour taste. Both over- and underfermentation also badly affect the texture of the final gari.

If too much liquid is pressed from the grated cassava, the gelatinization of starch during subsequent roasting is affected and the product is whiter. 

If sufficient liquid is not removed, however, the formation of granules during roasting is affected and the dough is more likely to form into lumps. The ideal moisture content is 47-50 %, and this is assessed visually by experienced gari producers.

Sieving is important to obtain a high-quality product, free of fibrous contaminants and with similar-sized granules. The granules must be roasted to about 80 ºC/175 ºF to achieve partial gelatinization of the starch.

If lower temperatures are used, the product simply dries and produces a dry white powder. Too high a temperature will cause charring of the product and make it stick to the roasting pan.

Packaging and storage 

The product is hygroscopic (it absorbs moisture from the air) and should be packed in airtight and moisture-proof bags, especially in areas of high humidity, to prevent mold growth.