An example ratio for 240g of cooked rice is about 22ml of red vinegar, 3–4g of salt, and 0–3g of sugar.
Red vinegar (akazu) has a rich flavor and umami, allowing you to greatly reduce the sugar compared to sushi rice made with regular rice vinegar. If you want to try a taste closer to Edo-mae style sushi, starting without any sugar is a good method.
From actual experience using red vinegar this time, the rice grains loosened more easily and were drier compared to when using regular rice vinegar, yet the rice still held together well when shaped. Not only the flavor of the mixture but also the handling characteristics of the sushi rice were favorable.
This is a practical note based on this particular red vinegar, rice, and cooking conditions. Because results vary with different types of red vinegar and moisture content, I recommend recording the state of the sushi rice along with the mixing ratio.
Initial Mixing Ratio
Start by mixing 22ml red vinegar, 3g salt, and 0g sugar. Combine while the rice is still warm by cutting and folding with a rice paddle.
If the saltiness feels insufficient, adjust in increments of 0.5g the next time. If the vinegar’s acidity is too sharp, before adding sugar, check the amount of red vinegar and the firmness of the rice.
When Adding Sugar
Adding 1–3g sugar can mellow the sharpness of the acidity and make the sushi rice easier to pair with white fish and squid. However, too much sweetness can mask the matured aroma of red vinegar and the umami of the fish topping.
Comparing sushi made with 0g and 2g sugar on the same topping helps to grasp the difference.
Recording the Mixture
Record the rice variety, water amount before cooking, cooked rice weight, amounts of red vinegar, salt, sugar, and the temperature of the sushi rice. By changing only the mixing ratio and keeping the other conditions unchanged, you can identify points for improvement.
Summary
For red vinegar sushi rice, start with about 3–4g salt and 0–3g sugar for 240g rice and 22ml red vinegar. Ultimately, adjust sweetness and acidity according to the fish topping you pair it with.
