Sushi-zu is a very delicate tasting dressing used to flavour rice to be used for sushi.
It is a mixture of rice wine vinegar, sugar, and salt. The sugar gives the rice a sheen. Some recipes will add a very small piece of kombu kelp for additional flavouring.
Generally, you use about 1 tablespoon of dressing to 1 cup (4 1/2 oz / 130g) of cooked rice.
The further ahead of time you make it, the better the flavour is, as this allows the flavours time to marry.
You can buy this already made in bottles, generally sold in English as “Seasoned Rice Vinegar.” One brand, Mitsukan, contains “rice vinegar, high fructose corn syrup, salt, monosodium glutamate, brown sugar, disodium guanylate, and disodium inosinate.” The makers advise that you use 2 tablespoons of their Sushi-zu per 1 cup (4 1/2 oz / 130g) of cooked rice
The treated rice is called “Sushi Meshi.”
6 tablespoons rice wine vinegar
2 tablespoons sugar
1 teaspoon salt
[optional: small sliver of kombu kelp]
Mix above ingredients in a pan, put on stove over medium-low heat, and stir until salt and sugar have dissolved. Don’t let it come to a boil; remove just before it looks like it wants to. Alternatively, mix in a measuring jug, and zap in microwave for 60 to 90 seconds, stirring occasionally, until sugar and salt have dissolved. Remove kombu kelp, if used. Let cool, then store or use. Best if made at least a few hours ahead.
Will keep stored in refrigerator for several weeks in a covered container.
“Zu” means “vinegar.”