Fermentation: The New Alchemy

fermentation illustration.

The alchemists of the medieval world believed they could turn lead into gold. Alchemy was “the quest for material perfection, produced through a creative activity, in which humans and nature collaborate.”1 

Turning lead into gold, of course, proved elusive. But humans’ ability to collaborate creatively with nature to turn low-value materials into something of greater worth? The alchemists were onto something there.  

Microflora — organisms too tiny to see without a microscope — are nature’s original alchemists. Over millennia, bacteria and fungi developed the ability to turn almost any molecule into the energy they need to live and reproduce. And with a little help from us humans, certain microflora can be “trained” to turn the molecules in their environment into not just energy for themselves, but also energy for us, in the form of food products. 

But this isn’t alchemy. It’s fermentation 


Fermentation is a natural process you probably already know something about. You may enjoy some traditional fermented foods. Think bread, pickles, kimchi, sauerkraut, tempeh, miso, kombucha, beer, and wine, to name just a few of the hundreds of fermented foods and drinks enjoyed by cultures all over the world. 

Fermentation is central to everything we do at Perfect Day. While we don’t exactly make gold from lead, we do something else: we make dairy proteins from plant sugars. 

How does it work? Keep reading! 

Fermentation Process 101 

In biology, the word fermentation has a pretty narrow definition, referring to a microorganism’s metabolic pathway for converting food into energy in an environment with no oxygen. Food makers have long borrowed this natural process to bring about desirable changes in whole foods 

There are three main ways fermentation is used by food makers.2 Traditional fermentation has been used for millennia to transform foodand biomass fermentation is a method that’s been in use for a little more than a century.

The method Perfect Day uses is the most recent, and it’s known as precision fermentationIt allows us to make super specific, highly pure ingredients. In our process, microflora convert sugar into whey and casein, dairy proteins that are useful to food makers for their top-notch nutrition, functionality, and versatility. 

But to understand Perfect Day’s process, it’s helpful to first know a bit about how traditional and biomass fermentation work. 

Three Ways to Use Fermentation for Food 

Here are some details about the ways fermentation is used in food production.  

  1. Traditional fermentation has been used for thousands of years. It was likely discovered accidentally when people noticed how their food could be changed under certain conditions.

    Imagine you’re an early nomadic human. Herd animals have been recently domesticated for meat and milk. You’ve done your morning milking and you’re getting ready to travel for the day. You decide to store the milk for later — inside a pouch made from an animal’s stomach.You carry it with you as you travel, bumping along under the hot sun for hours. Later, feeling a familiar pang in your belly, you remember the milk you’d stored that morning. When you open your animal skin, you realize the milk has changed. It’s thicker, and a little sour. Unbeknownst to you, tiny, invisible organisms (microflora) that were present inside the pouch have been at work fermenting your milk into something like what we’d recognize today as yogurt.3

    In traditional fermentation, agricultural products — legumes, grains, milk, or even meat — are inoculated with live microflora in order to transform those products. Early nomads could not have realized that this transformation was due to the natural action of microflora, but over time, they figured out how to create the right conditions to make it happen. Since then, fermentation has been used to influence flavor and texture, prevent spoilage, and improve nutrition and bioavailability (the ease with which a food or nutrient is digested by the human body). 

  2. Biomass fermentation is similar to traditional fermentation, but the final, edible product is the microflora itself. Some microflora are incredibly nutritious! In biomass fermentation, fungi or bacteria are introduced to a substrate (the flora’s food source) on which they eat, grow, and reproduce. The process capitalizes on microflora’s exponential reproduction rate. Whereas growing crops or raising animals can take months to years, microflora populations can double in hours or minutes. The resulting mass of cells — the biomass — is high in protein and fiber and useful in flavor additives and meat substitutes.  The first biomass product, Marmite, a spread made from the yeast involved in beer brewing, was introduced early in the 20th century. Quorn, introduced in the 1980s, is a meat alternative made of fungal biomass. Biomass fermentation represents a growing segment of the alternative protein industry.
  3. Precision fermentation creates useful products by combining microflora’s natural ability to turn sugars into other materials with the modern tools of biology. Remember the alchemists, who strove to collaborate creatively with nature to make high-value products from lower-value ones? Precision fermentation is the same thing — except it actually works! With today’s modern biological tools and understanding of genetics, humans can co-opt microflora’s natural inclination to make energy, and repurpose it to produce almost any complex organic molecule.4

Though you may not have heard of it yet, precision fermentation has been widely used across industries for a few decades. In the food industry, we use this process to make vitamins and flavors, and in the medical industry, to make life-saving insulin and antibiotics.

An example from the world of cheesemaking: before 1990, calf rennet (a byproduct of the veal industry) was used to curdle milk in the first step of cheesemaking.5 Today90% of cheese made in the United States uses fermentation-produced chymosin, the major enzyme in rennet responsible for that curdling action.6 Perfect Day uses this same kind of fermentation to make our animal-free dairy proteins. 


Now that you know some of the different ways fermentation is used to make all kinds of food products, let’s explore how Perfect Day uses fermentation to make a lot of protein all at once.  

Fermentation at Scale 

A fermentation tank  also called a bioreactor  is the environment our microflora need to flourish. Think back to the milk curdling inside that nomad’s animal-skin pouch. Inside the pouch were some microflora and the perfect conditions to help it turn the milk into yogurt: the right temperature, the right level of agitation, and the right feedstock (the milk itself). The bioreactor does the same thing, providing our microflora with the just-right conditions for making a lot of protein.  

It works like this: 

We start with a sterile, empty bioreactor and fill it with growth media: a nutritious liquid that contains the plant-based sugars our microflora thrive on. It also has water, oxygen, nitrogen, salts, minerals, and vitamins. 


Next, we inoculate the growth media with our microflora — that just means we add the microflora to the mix. We control the environment inside the bioreactor precisely, adjusting the temperature, pressure, pH, and stirring action to give the flora the perfect conditions to eat, grow, and multiply. As they consume sugar and increase exponentially, they also pump out copious amounts of our desired protein.  

The fermentation process ends when the sugar is all used up and the flora stop multiplying. The broth — now containing water, microflora, protein, and leftover growth media — is drained from the bioreactor. The protein is separated from the microflora, filtered, purified, and finally driedThe process is sterile and safe from start to finish. The end product is an extremely pure protein powder ready for use by food makers. 

Fermentation to Create Sustainable Products

Fermentation is pretty cool, right? When you realize that natural microflora can be trained to convert almost anything into almost anything, it opens up a brand-new world of possibility. Innovators all over the globare using fermentation to transform not only how we produce food, but also medicine, beauty products, and fashion. 

Consider how resource-intensive the current food industry is. We live on a finite planet where land, water, and energy are scarce. Demands on those resources will continue to grow as the global population does, and as standards of living rise across the world. But glucose and other carbohydrates, just like microflora, are plentiful all over the world, and they can be grown sustainably and inexpensively. Fermentation is extremely efficient. We have to feed people, and fermentation helps us make more nutritious food with fewer resources, quickly. It just makes sense. 

Our global environmental challenges are not insurmountable, but they require creative thinking and an understanding of the natural world. We’re taking our inspiration from nature already, and we’ve only just scratched the surface. 

The pursuit of alchemy centuries ago was primitive and not quite science. Today, we can see that it was little more than a fantasy. Turning lead into gold may not have panned out, but the dream of transforming substances is still alive, and today we have the knowledge and tools to turn it into reality. Humans and nature can collaborate creatively to find solutions. 

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