to turn soymilk into tofu by adding nigari (magnesium chloride) or calcium sulfate. it is also achieved on a home scale by adding an acid such as vinegar or lemon juice to create a substitute for buttermilk in recipes.
and finally, it unintentionally happens when adding cold soymilk to hot coffee, which creates curdles and little tofu-y bits. (this can be avoided by putting the soymilk in the bottom of the mug and slowly adding the coffee to cook/acidify the soymilk slowly, which creates far smaller particles of tofu.)
see also tofuification
origination:
tofuify first appeared at vegsource by alextree August 29, 2002
tofuification first appeared in a post at livejournal's vegancooking community by postpunkjustin 2007-06-24
you must first tofuify your soymilk before adding the rest of your liquid ingredients. when all liquids are combined, you may add the dry ingredients and incorporate.