It is everywhere.

But as sushi made its way into foodies' hearts across the globe, one thing has persisted in making sushi sushi.

And it's right there in the name.

The word "sushi” actually refers, not to the fish, but to the rice that was originally used to preserve the fish.

Some of the earliest documentation of sushi comes from China thousands of years ago.

During the monsoon season, floods pushed fish into rice paddies and farmers who caught the fish needed a way to store them for extended periods of time.

So they salted the whole fish, packed it under weights with cooked rice, and sealed it in a barrel.

Months later, bacteria had converted sugars in the rice into lactic acid, which helped prevent the fish from spoiling.

The pickled fish was eaten and the rice was tossed out.

This preservation method spread to Japan around the 8th century, where they later shortened the fermentation time and began eating the sour-tasting rice with the fish.

And when rice vinegar was invented around 1600, it was used to flavor the rice instead of waiting for it to ferment. Later, the invention of nori sometime before the 19th century led to maki, or rolled sushi.

18th century sushi was often 3 to 4 times bigger than what we see today and was served as a street food in Japan.

As it moved indoors, restaurants wanted to distinguish their sushi as more refined, so they started making the petite nigiri we know today.

Only after the invention of refrigeration in the 20th century did raw fish sushi become more common.

In the 1960s, sushi landed in the US and ended up at the first American sushi bar, Kawafuku, in Los Angeles' Little Tokyo.

It eventually became popular all across the US by the 1980s and the rest is history.

Sushi rolls in particular are continuing to make their mark in American cuisine.

You've got the Philly roll with its very un Japanese-ingredient of Philadelphia cream cheese, the the California roll made with avocados and fake crab meat.

And many many more nontraditional ingredients.

"Oh my God! The sushi burrito is living."

"This is deep-fried sushi."

It was also in the States where the maki roll was turned inside-out, reportedly in response to an American squeamishness about seaweed.

But through it all, the flavor of the vinegared rice is still a staple, tying today's sushi back to its very practical past.