Rolls, commonly known as nigiri rolls, are the most popular type of sushi in the West today, but weren’t made until about 1750. This is due to one of the main ingredients of sushi rolls, seaweed ( ). The diet of three meals a day was introduced by the Japanese, changing from brown rice to white rice. It is also essential for making rice vinegar.

During the Muromachi period (1336-1573), the Japanese invented the term “namanare” or “namanari”, which means “partially fermented”. Unlike sushi, which is often cooked, namanare is made with rapidly fermented rice. In other words, by adding namanare, sushi changes from kimchi to rice. After namanare was invented in the Edo period, sake and sake lees were mixed with vinegar to speed up fermentation.