Nigari’s main component is magnesium chloride, which is naturally extracted from clean seawater.
It is used as a coagulant in making tofu. Old days, People evaporated seawater to make salt and after salt was taken, left over portion is Nigari. So it is purely from Seawater. And the way it was found was by accident over 2000 years ago in China that they accidently mixed soy milk with Nigari and saw soy milk started to form. It is simmilar situation with Cheese. Thanks god that they had a gut to eat them.
Soon after, Tofu traveled to Japan and started to consume by monks who does't eat animal meat. They it becomes popular in Japan as great protein source.
Our freeze dried tofu is used natural made Nigari from pure seawater and it is totally safe for human and dogs!