Cassava flour is easy to make with basic kitchen equipment. It’s gluten free for those with celiac problems. I use it for making pancakes, slices and cookies, and mix it (half/half) with other flours for making breads or pizza dough.

One cassava plant can yield a good crop of tubers

One cassava plant can yield a good crop of tubers

Cassava, also known as Tapioca or Manioc, is an important staple crop for many populations in the tropics, especially throughout Central and South America, Africa and Asia. It’s become a popular plant in many warm climate gardens here in Australia but very few people seem to harvest and use it. It grows easily from stem cuttings and needs a long growing season of around 8 months to produce a good tuber harvest.

Cassava roots don’t keep long after they are harvested and need to be cooked or processed within three days. This presents a challenge it you dig up a large plant with more than you can eat in a few meals. Making flour is great way to preserve and store Cassava and the finished flour will keep for several years in an airtight glass jar.

The Cassava plant contains alkaloids and glycosides (cyanogenic glycosides), which forms hydrocyanic acid (Prussic Acid). These natural plant toxins are removed from the tubers before eating by either boiling (they dissolve readily in water so make sure you discard the water after cooking) or can be reduced through fermentation and oxidisation through drying. The cyanides are in all parts of the plant, with higher concentrations in the plant stems and skin of the roots. These toxins are dealt with through fermentation and oxidisation in the following process of making Cassava flour from the raw tubers.

Making Cassava flour in 5 easy steps

Grating the fresh cassava roots

Grating the fresh cassava roots

Step 1. Harvest and Peel the tubers

After harvesting remove any soil clinging to the skin of the roots before peeling. The freshly harvested roots need to be thoroughly peeled. The skin is actually quite thick, up to 2mm, and tough and can often be readily separated from the flesh. The skins need to be discarded, don’t use them for cooking or making stocks, however they can be used for mulch or put through the compost heap.

Step 2. Grating

Once the roots have been peeled and cleaned, they need to be grated. You can do this with a standard kitchen grater or an electric food processor. The finer you grate the roots, the better for several reasons. Firstly, the smaller and finer the grated pieces are the more surface area you’ve created, which in contact with the air will oxidise and help break down the prussic acid. Secondly, finer particles will dry faster and when dry will be easier to grind into flour.

Grated cassava root

Grated cassava root

Preparing to hang the grated tubers

Preparing to hang the grated tubers

Step 3. Hanging

Robyn Francis ready to hang the grated cassava overnight

Robyn Francis ready to hang the grated cassava overnight

Place the freshly grated flesh on a large clean cloth or tea towel then tie the corners and hang it overnight or for at least 5 hours. I usually hang mine over the kitchen sink. The hanging serves two purposes. One is to allow any excess moisture to drain off, the other is to allow a brief fermentation to occur, which further breaks down the prussic acid. Wring out any moisture before drying (Step 4)

 

Step 4. Drying

Spread the grated cassava out to dry, no thicker than a few millimetres. Ideally you want the cassava to be fully dry within 2 or 3 days otherwise it may start to mould. In dry sunny weather I’ll spread the cassava in thin layer on flat surfaced containers, such as baking trays or winnowing baskets, to dry in the sun. The drying can take several days. If you don’t have an enclosed solar dehydrator and are drying in direct sun out doors, make sure you bring the trays in overnight and cover the cassava with dry tea towels. If the weather is too humid or wet I’ll either use an electric food dehydrator or put the trays in the oven to dry. If you’re drying in the oven make sure it’s on the lowest temperature setting and have the oven door slightly ajar to let the moisture escape. I usually put the handle of a wooden cooking spoon in the oven door to keep it ajar.

Cassava drying on tray

Cassava drying on tray

Step 5. Grinding and Storing

Once the grated cassava is completely dry and crisp it needs to be immediately put into airtight storage, preferable large airtight glass jars. You can grind it as soon as it’s dry and put the ground flour into airtight storage, however even if you’re leaving for a day or so before grinding make sure you keep it in airtight containers to prevent re-humidification. Once it’s in an airtight container, you can safely keep the dried grated cassava for an extended period until you’re ready to grind it.

Grinding can be simply done with a blender or vitamiser. The drier and crisper the grated cassava is the easier it will grind up into a fine powder. I usually sift the ground flour though a fine kitchen sieve to separate any large or coarse bits and add them back into the next batch to grind.

left: dried grated cassava root, right: ground cassava flour

left: dried grated cassava root, right: ground cassava flour

 

RECIPE

Gluten-free Almond Slice with Cassava Flour

Ingredients:

  • 1 ¼ cups Cassava Flour
  • ¾ cup Almond meal
  • 1 cup raw sugar (or natural brown sugar
  • 60gr butter – melted
  • 2 eggs
  • ½ tsp baking powder
  • ½ tsp vanilla essence
  • ½ cup of Almond flakes or slithers for topping

Method:

  • Pre-heat oven to 1700C
  • Line a lamington tray with baking paper
  • Mix all dry ingredients together in a bowl (except for Almond flakes/slithers)
  • add eggs, butter and vanilla essence and mix thoroughly
  • Spread mix evenly onto baking paper in lamington tray (approx. 1 cm thick)
  • Sprinkle almond flakes/slithers evenly over the mix
  • Bake for 25-30 minutes
  • Cool on cooling rack
  • Slice to desired portion sizes
  • Store in airtight container.

 

Cassava-Harvest-Robyn-FrancisRobyn Francis

International permaculture pioneer, educator, author and practitioner, walks the talk with passion and humour at her permaculture farm, Djanbung Gardens in northern NSW, Australia.