Mentsuyu is Japanese soup base used in soba and udon noodle dishes. It’s made from sake, mirin, soy sauce, kombu, and katsuobushi (dried bonito flakes).
There are two types of mentsuyu:
- Kaketsuyu (かけつゆ) – the sauce is poured hot over boiled noodles to make noodle soup
- Tsuketsuyu (つけつゆ) – “dipping soup” for chilled noodles
“Straight” or Dilute
When the bottle says “straight” (ストレート), you do not need to dilute the sauce with water. However, many of the brands are concentrated and they require you to dilute the soup base with water depending on the recipe. Some says to dilute 3 x and some says 2 x.
In Japanese grocery stores, you will see different types of “soup base” for noodles. Some bottle might say it’s for Zaru Soba like the bottle below and it also says ストレート (straight – no diluting!).
At Japanese grocery stores, there are many brands of Mentsuyu. All bottles have Japanese word “つゆ” (Tsuyu), short for Mentsuyu.
If your local Asian grocery stores don’t carry Mentsuyu, you can make Homemade Mentsuyu from scratch! It’s easier to buy ingredients such as kombu and dried bonito flakes (katsuobushi) in Asian grocery stores than Mentsuyu.