Togakushi Soba

Prepare Dashi: In a pot, combine 1500 grams water and 10 grams kombu. Let the kombu soak for 30 minutes. Heat the pot over medium-low heat. Just before the water boils, remove the kombu.

Add 20 grams katsuobushi to the hot water. Bring to a gentle simmer for 30 seconds, then turn off the heat. Let the katsuobushi settle for 5 minutes. Strain the dashi through a fine-mesh sieve lined with a paper towel or cheesecloth, ensuring not to squeeze the katsuobushi. Set aside 400 grams of dashi for the tsuyu.

Prepare Tsuyu: In a separate saucepan, combine 80 grams usukuchi soy sauce, 80 grams mirin, 40 grams sake, 10 grams granulated sugar, and the 400 grams dashi. Bring to a gentle simmer over medium heat, stirring until the granulated sugar dissolves. Remove from heat and let the tsuyu cool completely.