To make sushi rice, you need to mix it with sushi vinegar.
Aside from adding flavor to rice, addition of vinegar to cooked rice helps to prevent rice from going bad.
The ratio we use at Breakthrough Sushi is Rice Vinegar: Sugar: Salt=5:3:1 (i.e. 5Tbl Rice Vinegar, 3Tbl Sugar, 1Tbl Salt).
Some of the common recipe calls for 5:2:1. Traditional Sushi restaurants in Tokyo use no sugar, just rice vinegar and salt only.
At your local supermarket (Whole Foods or Asian Market), you may find “seasoned” vinegar or sushi vinegar, which has sugar and salt already added.
Here are some examples of seasoned sushi vinegar.
Marukan Seasoned Sushi Rice
Kikkoman Sushi Vinegar
Mitzukan Sushi Vinegar
Sushi vinegar is added immediately after rice is done, not before it’s cooked. This will make some of the vinegar evaporate, thus coating grain of rice with sugar to help making rice stick together.