Ponzu is a citrus-based sauce used in Japanese cuisine as a marinade or an addition to soy sauce. It is made with rice wine, rice vinegar, bonito fish flakes, and seaweed. After the liquid is cooled and strained, it is infused with a Japanese citrus fruit called yuzu. Other Japanese citrus fruits such as sudachi, daidai, and kabosu are also used.
It has a very distinctive taste that covers the flavor spectrum; it can be salty, bitter, sweet, and sour all at once. Ponzu combined with soy sauce makes a wonderful dipping sauce called "ponzu shoyu" that is really terrific with some lightly seared ahi. It's also used as a dipping sauce for one-pot dishes such as nabe and shabu shabu. One can also dip pieces of sashimi in ponzu sauce. A splash of ponzu in some rice can really liven it up. If you're tired of Worcestershire sauce, try a little ponzu with your grilled steak or dribbled on a raw oyster.