Are algae the food of tomorrow?

“It tastes like bacon. It’s crispy and then there’s this gigantic flavor explosion,” warns Beth Zotter, CEO of Umaro Foods. This San Francisco start-up produces bacon from an unexpected source: seaweed.

Beth Zotter is one of the many entrepreneurs who have decided to exploit the potential of algae, a category that includes thousands of marine species ranging from floating clumps of greenish plankton to long ribbons of kelp.

This booming sector must continue to grow, say scientists who believe algae have the ability to feed the world’s growing population. A few days ago, we crossed the threshold of eight billion inhabitants on Earth; in 2050, according to the United Nations, we will be ten billion.

According to one study, to feed that many people, global food production will need to increase by 50%, an increase that would require 567 million hectares of arable land. Cultivating so much land would run counter to efforts to combat climate change and protect species. This would involve destroying ecosystems like forests that trap carbon pollution and nurture biodiversity. However, the cultivation of algae, in their various forms, could make it possible to meet these new nutritional needs.

“This plant does not need fresh water. She doesn’t need soil. It doesn’t need fertilizer,” says Charles Yarish, professor emeritus at the University of Connecticut. “She needs sea water and light. »

Companies are not kept waiting and are already taking advantage of the potential of algae. In the US aquaculture sector, this is already the most promising area. By 2027, the global market could be worth €95 billion, up from €40 billion in 2020. Here’s what to know about seaweed and the confusing ways it could show up on our plates.


There would be up to a million different species of algae. However, two categories suffice to classify them.

Macroalgae are the first. Here are stored the huge columns of kelp, which form underwater forests, and the sargassum, known to wrap around the ankles of swimmers. Microalgae, microscopic organisms like phytoplankton that are the foundation of the marine food chain, are the second.

It is the biological make-up of algae, ie the way they grow and the nutrients they contain, that make them so attractive to entrepreneurs, researchers and growers.

Like plants that grow on dry land, they thrive through photosynthesis: they convert solar energy and carbon dioxide in the sea and atmosphere into plant matter. But unlike plants growing in soil, algae don’t need to produce a supporting structure.

“The reason algae grow so much faster [que les plantes terrestres], is that they are suspended in water. They don’t require structural material to stay upright,” says Charles Greene, an ocean scientist from the University of Washington.

Some species of kelp can grow 60 to 90 centimeters per day.

This rampant growth is the most practical way to absorb carbon dioxide, a ubiquitous greenhouse gas in the world. When carbon dioxide pollution is too high, the planet heats up and the oceans acidify to the point where they become uninhabitable for sea creatures such as shellfish and coral; we are talking about ocean acidification. In the northwest Pacific Ocean, researchers are currently trying to grow kelp to temper the acidity of the water.


According to Charles Greene, the real climate benefit of algae comes from their ability to feed the world while taking up less space than terrestrial crops. Proponents of seaweed point out that the United States alone has 11.1 million square kilometers of territorial waters that can be used to grow seaweed, which would spare terrestrial ecosystems.

In addition, studies have shown the important dietary potential of seaweed. They are full of protein, fiber, are rich in micronutrients such as iron, and full of vitamins. While researchers are just beginning to study the potential health benefits of microalgae, they have already discovered species rich in protein and amino acids. Both sustainable and nutritious, seaweed is “revolutionary,” to use an expression uttered recently at a United Nations conference on the oceans.

In an analysis published last month, Charles Greene and his colleagues argue that seaweed farms could produce all the protein the world needs in 2050.

“We don’t think everyone will necessarily have access to algae protein, but we are clear that we need to look for alternatives,” he says. Over the next decade, microalgae will become increasingly important in the human food supply. »


Seaweed has been present in cuisines all over the world for millennia. Noris, the seaweed that wraps maki, were popularized by Japan 400 years ago when the country was beginning to cultivate it. In Hawaii, limu is part of the traditional diet. In Scotland and Ireland, white seaweed is used in the composition of desserts and certain beers. But it is today China that cultivates the most seaweed in the world, mainly intended to be eaten.

According to Charles Greene, in the United States, it was in the 1970s that we began to be interested in algae. Gasoline shortages then pushed scientists to look for other sources of fuel. Like corn, seaweed can be turned into ethanol and used as a gasoline substitute. For an equivalent crop area, algae produce 10 to 100 times more fuel than corn.

“We figured out how to make these algae grow pretty well. But it is quite expensive to cultivate them, and the oil is not very expensive”, affirms Charles Greene. According to him, this explains why algae have never imposed themselves as a source of fuel.

However, microalgae cultivated for human consumption are managing to find a place in the meat substitute market. Companies like Impossible Burger and Beyond Meat use plants to replicate the taste, look and texture of meat.

“I was excited about things like Impossible Foods,” says Charles Greene. “These plant-based substitutes are made with things like soy and peas, but I say, seaweed is way more nutritious. These things are cardboard compared to seaweed. »

The meat substitute market continues to grow (one projection predicts it will be worth 12 billion euros in 2029) and seaweed is about to become a commonplace ingredient in the manufacture of bacon and hamburgers.

To improve meat substitutes, seaweed is an essential ingredient. The pigments of red algae make it possible to reproduce the color of beef. Their umami gives a natural taste to seafood substitutes. In addition, the nutrients like omega-3 fatty acids they contain make the food healthier.


According to Liz Specht, vice president of science and technology at the Good Food Institute, a nonprofit that promotes meat alternatives, while using seaweed to feed a voracious world makes sense on paper, there are still a few things to overcome. difficulties before being able to cultivate microalgae on a large scale.

According to her, when growing algae in an inexpensive pond like a man-made pond, at some point the algae will grow so fast and become so dense that the light can no longer find its way in and their growth will slow down. stopped.

“We can overcome these difficulties using more sophisticated bioreactors equipped with LEDs or by passing the algae through tubes that offer a larger culture surface,” she explains. But then the production becomes particularly expensive.

While new methods of growing microalgae are constantly emerging, none are effective enough to be scaled up, she observes.

Their genetic cousins, macroalgae, are quickly making a name for themselves. Unlike microalgae which need more direct access to sunlight, macroalgae can grow vertically, up to 2.50 meters below the surface. In Maine, the largest producer of algae in the United States, their production is expected to double by 2025.

It is in this state that Beth Zotter sources the seaweed to produce her plant-based bacon and other meat alternatives that have not yet been revealed.

“There is a colossal windfall there that has been completely neglected,” she says astonished. Seaweed should be the protein source of the future worldwide. »


Leave a Comment