from google
tofu, also known as soybean curd, is a soft, cheese-like food made by curdling fresh hot soymilk with a coagulant. Traditionally, the curdling agent used to make tofu is nigari, a compound found in natural ocean water, or calcium sulfate, a naturally occurring mineral. Curds also can be produced by acidic foods like lemon juice or vinegar. The curds then are generally pressed into a solid block.
from Merriam-Webster OnLine
Main Entry: bean curd
Function: noun
Date: circa 1889
: a soft vegetable cheese prepared by treating soybean milk with coagulants (as magnesium chloride or dilute acids) -- called also tofu
Pronunciation: 'tO-(")fü
Function: noun
Etymology: Japanese tOfu
Date: 1771
: BEAN CURD
Edited by nitsuj on 2002-08-11 11:55:54