Læsø Tang: Seaweed – the super food Danes are learning to love

By Signe Hansen | Photos: Læsø Tang

In the waters around Læsø, where salt concentrations are high and pollution is low, seaweed flourishes. Here, Danish couple Rie and Leif Ladefoged harvest certified organic seaweed packed with health benefits. Rich in vitamins, minerals, and natural umami, seaweed is a nutritional and culinary powerhouse ingredient that offers a sustainable food source from the sea. Now, the couple is teaching the Danes how to love it.

Rie’s journey with seaweed began in 2010, after attending a lecture by biophysicist and seaweed advocate Ole G. Mouritsen. “He mentioned that the clean waters off Læsø are ideal for harvesting seaweed, and that stuck with me,” she explains. After some research, Rie began harvesting, drying, and experimenting with different seaweed products.

Harvesting seaweed.

“The benefits of seaweed are huge,” says Leif, who also works with Læsø’s famous seaweed roofs. “It’s incredibly nutrient-dense, full of umami flavour, and you don’t need to fertilise or irrigate it – just harvest it carefully and respectfully.”

But despite being good for your health, your taste buds, and the planet, turning seaweed into a business was not easy. “We tried selling dried seaweed through health stores at first, but really, no one bought it,” Rie says with a laugh. “Changing people’s food habits is difficult, so I had to get creative.” She began developing her own line of products – seaweed pesto, pickled bladderwrack, crisps, and bread – and customers began to take notice.

The seaweed schnapps and pesto are some of the most popular products when people visit the farm shop.

Then came a breakthrough in the form of the book Professorens Grønne Grød. Published in 2024, the book presents a health-focused porridge blend which includes seaweed for its nutritional and digestive benefits. Following extensive publicity, Læsø Tang was contacted by Skagenfood to provide seaweed for a meal box based on the book. “That really boosted interest,” Rie says. “Once people realised our seaweed was in those boxes, our web shop started buzzing.”

Though demand has increased, Rie creates nearly all the products herself. One product, however, has Leif’s fingerprints all over it – the seaweed schnapps. Leif also handles all the administrative work and was responsible for getting the business certified organic, a process that requires regular testing of both the water and seaweed for pollutants such as PFAS, E. coli bacteria, and heavy metals.

Beyond food, the couple is passionate about sharing their knowledge. Rie leads guided seaweed tours along the shore and offers vegetarian lunches in the farm shop, where dishes featuring seaweed highlight local produce. Together, they are also deeply involved in environmental projects on Læsø, including sustainable fishing and marine habitat restoration.