Yamasei's mustard powder is made from stone ground organic Barukan (Vulcan in English) mustard seeds. As you might gather from the Oni (Demon) on the packaging, this karashi is very spicy yet still has the most mustardy taste. To retain the mustard flavor, Yamasei takes great care when removing the oil and grinding the seeds to a paste. Spicy karashi mustard is perfect with Pork Belly Kakuni, Japanese Potato Salad and Karashi Cucumbers. How to use Yamasei's Organic Karashi Mustard Powder: - Thoroughly mix 4 parts mustard powder with 5 parts lukewarm water (between 104℉ and 140℉). Allow the mustard paste to rest between 5 and 15 minutes to develop the spicy taste. - Do NOT use boiling water or cold water. - If you don't let the mustard rest after mixing, the taste may be bitter. - After resting, use the mustard paste as soon as possible. About the producer: Located in Kagawa Prefecture, Yamasei is passionate about producing high quality karashi mustard.