Historically, few seaweeds in American waters had much commercial culinary value, though to make a blancmange, some people in the nineteenth century gathered Irish moss, which they steeped in hot milk to obtain the carrageenan, a gelatin-like substance. In the late twentieth century, as Americans learned about Asian, and particularly Japanese, foods, they were introduced to the use of a wider variety of edible seaweeds. Among the seaweeds that are gathered and sold in the United States are alaria, kelp, dulse, laver, and red and green algae.