Why do you have to rinse rice?

It removes excess starch, so your sushi rice doesn't turn into nasty glutinous slop. The texture of the rice is very important, so you'll need to rinse it several times before you steam it. Make sure the water is nice and clear after the last time you rinse it, and make sure you buy japonica or similar: if you use regular rice, you may not get good results.

I wouldn't worry overmuch about the nutritional content of white sushi rice (you can starve on a diet of it). It's what you put into your sushi that'll give it nutritional value.

Rice that says 'not to rinse' has already been cleaned and enriched with vitamins because of the nutrients removed in milling. Rinsing it will remove the vitamins. Rices that have not been cleaned and enriched need to be rinsed because they are dirty and sometimes have a powder added after milling. Sticky rice definitely needs to be rinsed several times, then soaked for a few hours, drained and finally steamed to cook.

I use California Calrose type rice for making sushi. I follow the basic cooking instructions on the bag. Then I use the sushi vinegar and salt when finishing off the rice during the cooling phase. I never rinse the rice and it always turns out perfect.

I never used to rinse rice when I lived in the states, because the instructions said specifically not to rinse it. Then I married a Samoan and moved to New Zealand. My husband's uncle who was visiting from Samoa found it strange I never rinsed the rice and told me that in Samoa, they rinse it extremely well. I told him in America the instructions say not to wash, but it seemed he may not have believe me. There were no such instructions on the New Zealand rice bag. So, I decided to ask one of my Samoan friends why it's important to them to rinse the rice. They said it's because there could be bugs in the rice bag. Well, for the last few months I've been rinsing rice in cold water a few times before I put it in the rice cooker. The other day, sure enough, a bug came out! I think I will always rinse the rice now. LOL

To rinse or not to rinse, this is the question. It will depend on the type of rice you bought and where it's from. The process of making "white" rice is taking the hull or husk off of "brown" rice. The hull contains all the rice bran and vitamins, the good stuff. There are many non-rinse white rices out there. They have had the lost minerals and vitamins sprayed on the rice grains. So to wash this type of rice is washing away some of the nutritional value.

Some other rices, especially those from outside US, say Jasmine rice from Thailand, Basmati rice from India, need to be washed very throughly, as to clean the rice. This means bugs, dust, dirt, and rocks are some of the things that can get inside the bag. This will also make the rice less sticky when cooked. The washing also rinses away the extra starch.

Traditionally Japanese rice, needed to be rinsed and washed to remove the talc powder used for anti-caking. Japan tends to be very hot and humid in summer, and adding powder to the hulled rice made it last longer and not stick together. So washing the rice in cold water and then rubbing the grains in your hands would remove the starch and the talc powder.

Generally one would rinse till the water ran mostly clear. Then it was put in a strainer and let to dry out and then put into the rice cooker with water and let to rest for 10-20 minutes. Fancy rice cookers have a timer for this reason.