Nori is a thin, crispy, ready-to-eat seaweed product made from laver (mainly Pyropia yezoensis) that has been cleaned, shredded, molded, baked / flavored. It originated in Japan and gradually developed from ancient collection and consumption to modern large-scale processed food.

1. Definition of Nori (Clearly Distinguishing)

1. Biology and Raw Material

Belongs to the phylum Rhodophyta, family Bangiaceae, genus Pyropia; the main raw material is Pyropia yezoensis (also known as striped laver), and Pyropia tenera can also be used.

Laver is a general term for red algae; all nori is laver, but not all laver is nori (similar to potatoes and potato chips).

The algal body is thin and flat, purple / red when fresh, and dark green when dried.

2. Food Science Definition (National Standard / Industry)

A thin / granular ready-to-eat seaweed product made from striped / Pyropia tenera laver, processed through cleaning → shredding into pulp → molding → drying / baking → flavoring.

Divided into two types:

Roasted nori (sushi nori): only baked, no seasoning, used to wrap rice or sushi.

Seasoned nori: flavored with vegetable oil, salt, sugar, sesame, etc., eaten directly as a snack.

3. Name Origin

The Chinese term “海苔” comes from the Japanese 「のり (nori)」, originally referring to seaweed in general, now specifically referring to processed laver sheets.

International common name: Nori.

II. The Origin and Development of Nori (Japan as the Main Line)

1. From Ancient Times to the Nara Period (Collection and Consumption, Before the 7th Century)

In Japan's Jomon period (about 10,000 years ago), there is evidence of consuming seaweed, with nori being one of them.

In 701 AD, the Taihō Code listed nori as a tax/tribute, being the earliest written record.

In 721 AD, the Hitachi no Kuni Fudoki recorded drying nori by the seaside, which at the time was either raw nori or simply sun-dried, not in the modern sheet form.

2. Heian to Kamakura Period (Noble Ingredient, 8th–14th Century)

During the Heian period (794–1185), nori became part of the noble diet, and in the Utsuho Monogatari (987 AD), it was recorded as a common food.

In the Kamakura period (1192–1333), the range of nori tribute expanded, spreading from the western regions to the eastern regions, and it was called 'rock nori'.

During the same period in China (Wei, Jin to Tang, Song), edible laver was also consumed, but the sheet-form processing technique of nori did not develop.

3. Edo Period (Birth of Modern Nori, 17th–19th Century)

In the mid-18th century (around 1750), processors in Asakusa, Tokyo, inspired by Japanese papermaking, shredded the laver, made it into pulp, spread it on frames to dry, inventing sheet nori (ita-nori), i.e., modern sheet-form nori.

The process was standardized: shred → pulp → mold → dry → roast, greatly increasing production and bringing it to common dining tables.

In 1796, 'Nori' appeared in English literature for the first time.

4. Modern Era (Global Popularization)

After the Meiji period, cultivation techniques matured, and Japan became the main producer of nori.

In the 20th century, with sushi going global, nori became an internationally used ingredient.

In China, from the 1980s onward, large-scale cultivation of the striped laver began, with Jiangsu, Fujian, and Zhejiang becoming main production areas, and the nori processing industry emerged.