Yesterday, there was a post here on Flavors of Brazil about the confusing nomenclature for the staple food plant cassava (or manioc, or yuca, etc. etc.) Let's hope that faithful readers of this blog will have already studied and memorized that post to avoid further confusion.
that post, because there is not just one plant that carries all those names, there are two. And the difference between the two of them is not insignificant by any means - because one is poisonous if not detoxified and the other is safe to eat in its natural state. Consequently, being able to correct distinguish between the two maniocs is a serious business, as an incorrect choice may be fatal.
Both plants have the same botanical genus - Manihot. The species that carries toxins is Manihot esculenta and that innocuous one is Manihot utilissima. In English, the two species are generally called bitter cassava and sweet cassava, respectively, and in Brazil, the toxic Manihot esculenta is generally known as mandioca and the non-toxic Manihot utilissima is called mandioca doce, macaxeira, or aipim.
The toxic properties of some members of this plant genus were long known to native American populations, who learned how to remove the toxins from the plant before consuming it. Variations of these techniques are still used today worldwide. Whatever treatment is used, the important thing is to remove cyanide from the plant, as ingestion of raw roots or leaves can cause severe and chronic illness, or even death. Toxins are removed naturally from the plant when it undergoes soaking in water, cooking or fermentation. Variations on all three of these techniques are used both at home and in industrial processing.
One of the most intriguing techniques for detoxifying cassava is one that native Indians used for fermenting cassava into a drink. It was described by anthropologist and shamanism scholar Michael J. Harner this way:
The sweet manioc beer (nihamanci or nijiamanchi), is prepared by first peeling and washing the tubers in the stream near the garden. Then the water and manioc are brought to the house, where the tubers are cut up and put in a pot to boil. … The manioc is then mashed and stirred to a soft consistency with the aid of a special wooden paddle. While the woman stirs the mash, she chews handfuls of and spits them back into the pot, a process that may take half an hour or longer. After the mash has been prepared it is transferred to a beer storage jar and left to ferment. … The resultant liquid tastes somewhat like a pleasingly alcoholic buttermilk and is most refreshing. The Jivarosw consider it to be far superior to plain water, which they drink only in emergencies.
This technique of masticating food to initiate fermentation is one used throughout the world from Asia and Africa as far north as the Arctic, where it was known to the Inuit.
In the next post on this blog, I'll provide a traditional recipe for a dish that used cassava leaves, which shows just how much care, effort and time are required to make cassava safe to eat.