In a small saucepan, pour mirin, sake, and soy sauce. Then add sugar and stir to combine.
Place the saucepan with the teriyaki mixture onto the stovetop and turn the heat to 248°F (120°C). Continue stirring until the mixture starts to boil.
Allow the teriyaki mixture to boil undisturbed for 15 seconds. Continue stirring while the mixture boils for another 15 seconds and lower the heat to 140°F (60°C).
Allow the teriyaki mixture to simmer over low heat for 5 minutes, stirring occasionally.
Notes
Use real Japanese ingredients, if you can find them, to make this authentic Japanese Teriyaki sauce recipe.I used Hon Mirin and Takara for the cooking Sake. I used Tamari, a gluten-free soy sauce as most sake and mirin are gluten-free too. Use regular soy sauce or simply “soy sauce” if preferred.Traditionally, mirin, sake, and soy sauce should have equal parts with 1 part sugar. Adding ½ tablespoon less soy sauce resulted in a better, not too salty mixture.Add equal parts mirin, sake, and soy sauce if preferred.Do not wait for the mixture to thicken when boiling or simmering. The teriyaki sauce will continue to thicken once cooled and if stored in the refrigerator. Cooled teriyaki sauce for 30 minutes to 1 hour at room temperature will result in a hardened sauce if boiled or simmered 1 to 2 minutes longer.This Homemade Teriyaki Sauce made ⅓ cup, about 5 servings with a little over 1 tablespoon per serving.