KosherEden Wasabi Powder is made from washed, cut and dried wasabi (Japanese horseradish) and Western wasabi (horseradish) that is ground into a fine powder. Mustard seed is ground and most of the oil is extracted, leaving about 4 percent of the oil in the seed. The seed is then ground again into a fine powder. The remaining oil in the mustard powder is needed to bind the wasabi and horseradish powders. All of the powders are then combined and mixed before packaging in sealed containers to preserve flavor and nutrients.