According to thefreedictionary.com: okara or soy pulp is a white or yellowish pulp consisting of insoluble parts of the soybean which remain in the filter sack when pureed soybeans are filtered in the production of soy milk.
I drink lots of homemade soymilk, so there’s plenty of okara around the house. It freezes well for months. In the fridge it lasts a week at most.