15-20 minutes. Generally, small taro under half a catty is boiled in cold water 15 minutes. Generally, taro is fine in powder, high in water content and small in size. After peeling, you can put it in a pot and cook it quickly. Usually boiled in cold water 15 minutes. Generally, more than a catty of taro is boiled in cold water for 20 minutes. Generally, taro powder is dry and contains little water. Even if it is sliced, it takes a long time to cook. Generally, it takes 20 minutes to cook in cold water, so it takes about 15-20 minutes to cook betel nut taro. Areca taro is oval. This variety is also called "Areca taro" because its skin is rough and there are areca seeds inside.