'Air protein' could soon become a key part of a healthy diet. Here's why

Why Solein, a strange new source of protein, could become the go-to food source in future.

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Credit: Solar Foods

Published: May 20, 2024 at 3:34 pm

There’s a big change happening with your food. Steadily, farms are being switched out for labs, crops with vertical walls of food, and meats with cultured cells, but now there’s a new option gaining traction – protein made from air.

This is by no means a new invention – Solar Foods launched its product known as Solein back in 2021. But the company is now upping the ante, officially unveiling its first factory that they’ve oh so very creatively dubbed, Factory 01.

With this, Solar Foods hopes to make air protein the new norm, leaving meats, dairy and other carbon-intensive options in the dust (or refined powder in this case).

But is this really a kinder option for the environment? How safe is it to consume? And how on Earth do you turn air into food anyway?


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How is it made?

In essence, it is just like making a beer. Well, sort of: similar to your favourite lager, Solein relies on a gas fermentation process. 

“Where beer uses sugar, wheat, and starch to convert the sugar material into alcohol, this is using gas as a feed which includes carbon dioxide – hence the term ‘air protein’,” Dr Ying Zhang, a molecular microbiologist and assistant professor at the University of Nottingham told BBC Science Focus.

A person wearing blue gloves handles Solein in its paste form
Solein can be turned into a paste or used as a powder - Credit: Solar Foods

Solein uses a special type of microbe that can grow by feeding on carbon dioxide, nitrogen and hydrogen. Using renewable energy, it splits the water molecules found in air, providing hydrogen.

The microbes are also fed a broth, including nitrogen, minerals, and other nutrients. Once the microbes multiply, they are separated from the liquid through centrifugation (separating molecules by spinning them really fast).

What is left is then dried into a fine powder that is roughly 60 to 70 per cent protein. This can then be used as a protein powder or turned into flakes, chunks or other shapes to mimic meats.

These microbes start their lives as hydrogen-oxidising bacteria (HOB) – that's bacteria that can use hydrogen as a source of energy. There are plenty of HOBs in use around the world, but very rarely for our consumption and are mostly found in animal feed, wastewater treatment and other industrial processes.

However, the process that Solein uses turns the bacteria into an edible substance that is fit for our consumption.

Is Solein safe?

A product that is high in protein, vegan-friendly, and kind to the environment – it’s a miracle! Well, not exactly. There are a few key drawbacks stopping Solein from being the next big thing in food.

Firstly, Solein is still awaiting approval in most countries (including the UK and US), only achieving novel food regulatory approval in Singapore so far. 


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Secondly, it’s the hydrogen. The fermentation process relies heavily on it, and it has a habit of going boom.

“Hydrogen is essential in this process, but it is a difficult explosive gas to handle, especially at the scale they’re operating at with this factory. It’s possible to use safely, but it wouldn’t be easy on a mass scale,” says Zhang.

“You have to engineer aspects to keep it safe and that would need to be your priority over production output and other aspects. It’s possible to scale this up, but handling hydrogen mixed with oxygen is a massive potential limiting factor.”

In short, it’s incredibly dangerous to handle. Solar Foods claim that they are “serious” about hydrogen safety, using appropriate materials to store the gas. “Hydrogen management is our team’s responsibility, as well as a key skill and a strategic asset,” Pasi Vainikka, the CEO of Solar Foods explained to BBC Science Focus

If Solein can set up a working (and safe) factory and get approval in other regions, there remains the concern found with any new product. While Solein contains the needed protein and other nutrients, it remains an unproven part of our diet. Currently, considering how new these types of foods are, there are no long-term studies into how they affect our bodies. 

Could it be the food of the future?

Solein has a lot of barriers to get past before it can become a mainstream food choice. It needs that all-important novel food regulatory approval in parts of the world other than Singapore, and it will take a long time before it can scale to a point where it is readily available.

However, the product does offer a promising solution going forward. It is free of gluten, dairy and soy, as well as being vegan and lacking in known allergens. This, for a lot of harder diets, could pose the sometimes challenging task of getting enough protein.

A photo of a bowl of soup that has used Solein
Solein has been tested in a wide variety of foods - Credit: Solar Foods

As a powder form, it is a versatile food option, and Solar Foods has used it to make pasta, gelato, snack bars and even ‘meatballs’. And, based on Solar Foods claims, it contains all the nine essential amino acids, carbohydrates, fats and minerals as any other food (these claims haven’t been confirmed by independent experts in the UK or the US).

However, Solein’s big selling point is its carbon footprint. It doesn’t need anywhere near the same amount of water for land irrigation or as much electricity as some factories do. Solar Foods claims it is about 10 times more climate-friendly than most plant-based proteins and about 100 times more climate-friendly than meat.

“As long as the hydrogen is being sourced in an environmentally-friendly way, this would have a vastly lower impact compared to the meat industry, especially compared to beef which tends to be one of the worst,” says Zhang. 

High in protein, kind to the environment, and with an expected price of €6 (approximately £5.15) per kilogram, it could change the future of food. If it passes regulation… and nothing blows up.


About our expert, Dr Ying Zhang

Ying Zhang is a molecular microbiologist with a focus on engineering biology. She is currently an assistant professor in the faculty of medicine and health sciences at the University of Nottingham.

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