All About Nori Seaweed (a.k.a Karengo)

Mar 17, 2023

Learn all about Nori seaweed in this short article ~ the situation with New Zealand Karengo, how it is farmed, the amazing nutritional benefits this delicious seaweed offers and how to use it in your everyday meals.

Nori is actually the Japanese word for a versatile genus of red seaweeds which are scientifically classified as Porphyra. Nori is a delicious, edible, and widespread sea vegetable with a number of different species (over 100). These species are similar in taste, structure, and nutritional offerings.

While nori is the most popular and universally used name for this type of seaweed, it is also known as karengo by Maori in New Zealand, laver by the Welch, Kim by Korean, and zicai by Chinese!

Learn All You Need to Know Abour Nori Seaweed

Karengo ~ New Zealand 'Nori'

In New Zealand, the collective name for the various species of porphyra is ‘karengo’ or ‘parengo’. It grows abundantly along our coastlines – to date, NIWA scientists have identified about 35 porphyra seaweed species growing in New Zealand waters. The colour, texture, shape and flavour vary according to the species, for instance, karengo’s blades (the equivalent of leaves on land plants) can be pink, purple, gold or green, ranging from huge sheets with the texture of cellophane to long, irregular ribbons. Some forms of karengo are more rigid while others are more tender and delicate. What they all have in common is that they are just one cell thick, making them unique among other kinds of seaweeds or sea vegetables.

Dried wild karengo has a brownish-purple colour, its texture is soft to the touch, and it offers a variety of flavours depending on moisture levels.

Karengo grows in the intertidal area of the New Zealand seashore, typically anchored to rocks. The sea vegetable is exposed to the elements at low tide for hours every day, then submerged at high tide. For much of the year, karengo cannot be spotted easily, as it can just look like a speck on the rocks, whereas at maturity and from a distance, it can resemble a torn black plastic bag melted onto the stone. Like land vegetables, spring is the primary growing season for the karengo sea vegetable.

Can I Buy New Zealand Karengo?

Karengo is considered taonga species (a gift) by Māori. While it can be gathered from the wild for personal use, only one licence has been granted for commercial harvesting, by the hand of a fixed amount, of this precious sea vegetable. This occurs between July and September along a defined stretch of coast in the South Island.

However, due to the Kaikoura earthquake in 2016, harvesting has been paused to give the seabed time to recover. While we cannot offer a commercially harvested local karengo, we have searched high and low for two similar alternative options, most closely matched to our local karengo. We offer a sustainably farmed nori from Korea or an ethically harvested wild nori from South America (the same species that grows locally here in New Zealand). Both are tested for contaminants according to strict New Zealand food industry standards.

Pacific Harvest offers only raw dried fronds – 100% seaweed with no processing, which can compromise nutritional quality.

How is Nori Farmed and Harvested?

Throughout Asia, virtually all nori is commercially farmed in large-scale seaweed farms, and then processed into sheets or wraps. This industry is long-established and thriving. The dedicated growth and farming process involves spores being bred and multiplied in laboratory pools where temperature and light are optimised to provide the right growing conditions. Nets are then seeded with spores and suspended in clean ocean water. As nutrients in the water nourish the spores along with sunlight, they grow into increasingly large strands of seaweed. In this ‘pole system’, nori nets are hung between poles. At low tides, the nets are exposed to air and become dry, so floating net techniques are implemented to enable nori to be cultivated in deeper sea areas.

After rearing in the open sea for 40 or 50 days, depending on the species, the first harvesting phase begins. Harvesting can last up to 5 months, with annual harvesting intervals every 10-15 days and 10-12 harvests. Nori strands are cut from the net, washed, and ground into a slurry. This is fed through a machine that flattens and dries the seaweed into uniform sheets (much like the process of making paper) before the sheets are roasted and graded for quality.

Processed nori sheet Processed seaweed sheet – more fat than seaweed in some cases!

Most nori snacks are made through this process and are also glazed, giving them their shiny surface and salty taste (if you look closely at some of these popular seaweed snacks which have been highly processed, there is very little seaweed and quite a lot of fat (we have seen up to 52%)! Read on to learn how you can add nori to your life without the need for processed seaweeds, which are sometimes fatter than actual seaweed!

The Amazing Nutritional Benefits of Nori

The nutritional profile of nori, karengo, and other red seaweeds includes relatively high concentrations of protein (nearly 30% protein), calcium, iron, fibre, potassium, magnesium, phosphorous, iodine, and vitamins A, B1, B2, C, D and E, as well as taurine (which helps to lower blood cholesterol). This sea vegetable has no fat and is a good source of omega-3 fatty acids, plus it offers natural anti-inflammatory, antibiotic, antifungal, antiviral & antiparasitic effects.

How to use Nori In Cooking

Pacific Harvest offers Nori Flakes for convenience. Download our Nori recipe brochure or read on for more inspiration.

Sprinkle the flakes into what you eat as a garnish or seasoning, or chop the fronds to the desired size. Nori fronds make a delicious, raw snack, but it is arguably the most versatile seaweed, as its flavour and texture can evolve depending on how you prepare it. When eaten dry, nori can taste similar to mushrooms. When moist or wet, the flavour becomes more akin to anchovy, and when baked, it can assume a nutty flavour. Given nori’s cellophane-thin composition, it doesn’t need to be rehydrated as it quickly soaks up any liquid from its surrounding ingredients when cooking.

Chop fronds into a Mediterranean-inspired sauce as a wholesome vegetarian alternative to anchovies
Sprinkle flakes as a delicate vegetarian garnish on egg dishes, seafood, rice, vegetables
Eat it raw as a moreish healthy snack or roast it gently with nuts and seeds as a healthy savoury snack
Add as a colourful herb or seasoning into vegetable bakes, salads, pesto, meat, sauces, smoothies and dressings.