It is not edible when it’s raw, but can be eaten after being processed. It has to be boiled, ground and put into a mold to take a shape.
Konnyaku is not made at home usually, because the bulb is highly toxic without being processed properly. The final product is a jello-like slab without flavor.
Many Americans, including my husband and son don’t like konnyaku, due to its texture. But shiratakis, which are now widely sold at regular grocery stores’ organic sections and organic food stores, are actually konnyaku. It is interesting that when the same food is shaped like noodles, Americans seem to have less problems.
Konnyaku is often stewed with other vegetables or boiled and topped with sweet miso as dengaku.
Konnyaku is getting more popular in Japan as a substitute of beef lever sashimi. Raw beef livers, which used to be served at restaurants as delicacy in Japan, sometimes made people seriously ill. The Japanese ministry of health eventually banned to serve raw beef livers at restaurants.