Making the sauce

• measure the katsuobushi flakes when using
• measure the rice vinegar, the sake and mix these with the flakes
• let stand for 30 min
• meanwhile measure the sugar and the mirin and add to a small pan. Start to slowly warm. Stir
• measure the soy sauce
• after 30 min strain the flakes from the rice vinegar sake mixture and add the liquid to the mirin and sugar
• Continue to warm and add the soy sauce, while making sure that all the sugar is dissolved
• bring to a simmer and roughly reduce the volume by half. When you see that there are many more small bubbles coming, you will be almost done
• Store the hot sauce in a air tight container and let cool. Remember that the viscosity of the sauce rapidly will increase upon cooling. (The ability to pour the sauce will reduce upon cooling)