Happy Sustainable Gastronomy Day! This UN Day, celebrated on 18 June, is dedicated to sustainable food production and consumption in the context of local culinary traditions. Did you know that biotechnology – the use of living organisms to make products – is both a key aspect of many culinary traditions as well as a cornerstone of sustainable food production? The reason for this is fermentation.

The theme of 2023 Sustainable Gastronomy Day is ‘Local Flavours, Preserving Global Heritage’. Fermentation, from the most traditional to the most innovative examples, is a key part of local and global food traditions and plays a crucial role in the sustainable food systems of today and tomorrow.

What is fermentation?

Fermentation refers to the process in which microorganisms, such as yeast, fungi, or bacteria, turn sugars into a different product, such as alcohol or lactic acid. Humans have been using fermentation for thousands of years to bake bread (yeast also produce carbon dioxide as they digest sugars, which allows the bread to rise) and produce beer, wine and other alcohols. Different varieties of yeast result in different types and tastes of bread and beer – for example, Brettanomyces bruxellensis is a yeast associated with typical Belgian beers like lambic, geuze, and kriek. Fermentation also plays an important role in food preservation. Bacteria in fermented foods, like sauerkraut, kimchi, or yoghurt, produce compounds like lactic acid that give these foods a distinctive taste and also reduce spoilage.  These uses of fermentation are referred to as traditional fermentation and they are an important part of food culture globally.

From fermentation to biomanufacturing

By the early 20^th century, humans understood that microorganisms were key for these fermentation processes, and that microorganisms could also make other products beyond helping make beer and bread and preserving foods. For example, citric acid, which occurs in a variety of fruits, such as citrus fruits, can also be produced by a fungus called Apergillus niger. The fungus is fed sugars and produces citric acid, in a process that can be scaled up for industrial fermentation. Citric acid is an important ingredient across the food and beverage industry and is still mainly produced through fermentation-based biomanufacturing.  

In the 1980s, this type of fermentation was further optimised through the use of gene technology. This is also known as precision fermentation. The birth of the modern biotechnology industry occurred when a yeast was modified to produce human insulin – providing a solution for diabetic patients beyond having to extract insulin from cow and pig pancreases. This breakthrough allowed for widespread production of key ingredients such as commodity chemicals, enzymes, vitamins, and amino acids through precision fermentation. For example, precision fermentation is used to produce microbial rennet – a key ingredient for cheese production that is otherwise extracted from veal stomachs. Most cheese is now made using microbial rennet.

Depending on the desired end product, precision fermentation can offer many benefits. In the examples of insulin and rennet production above, the fermentation process eliminates the need for animal extraction. Other examples, like vanillin or carotenoids used as flavourings and colourants, are found in small quantities in plant sources, and can be produced more efficiently by microorganisms. In other cases, like the production of riboflavin (Vitamin B2), the use of fermentation allowed to shift the production process from chemical to biological synthesis. This biomanufacturing process is more resource efficient and produces fewer greenhouse gases. Today, precision fermentation products are used across a wide variety of sectors beyond food and feed, including medicines and consumer products like detergents and cosmetics.

Alternative proteins – the role of precision and biomass fermentation

Fermentation continues to evolve: beyond transforming food, like in traditional fermentation, and producing ingredients, like in precision fermentation, the fermentation process can also be used to produce food. The newest uses of precision fermentation involve the production of animal proteins, such as dairy proteins (casein) or egg whites. This allows for cheese to be made without involving any animals, and with a smaller environmental footprint in terms of land use and resources.   

Another type of fermentation called biomass fermentation involves the production of microbial biomass as a food product. In this case the microorganism ferments and grows, and the biomass is then processed. One well-known example of this is Quorn, which uses a fungus called Fusarium venenatum to produce mycoprotein. These types of products can be used as vegetarian or vegan alternatives to meat, offering more diverse options in cooking and gastronomy.

Fermenting sustainability

Food systems face an increasing number of challenges, from climate change pressures on production to addressing food security for a growing global population. Fermentation underpins many aspects of our food systems from food transformation and preservation to ingredient production. Meanwhile, novel developments in precision and biomass fermentation support the diversification of our protein supply and production. Humans have a thousand-year history with fermentation – and hopefully a long future too.