We've put a man on the moon, but will we ever make cheese there? It may seem like a silly question, but the real possibility of settling other planets and satellites is becoming less and less the stuff of science fiction, and with innovations in that realm—though still theoretical—come real and practical questions of "what in the (new) world would we eat up there?"
In Dinner on Mars: The Technologies That Will Feed the Red Planet and Transform Agriculture on Earth (ECW Press), food scientists Lenore Newman and Evan D.G. Fraser attempt to answer that question, in all its scientific and cultural complexities. And with companies like Beyond Meat and Silk (which produces milk alternatives) becoming massive operations and household names, their ideas are as entertaining as they are plausible.
Written with wit and accessibility, Dinner on Mars, is a glimpse of a strange future filled with lab-grown meat and fermented yeast ice cream. More than just a theoretical lark, Newman and Fraser's offering is roadmap of not only where we might be going but where we are and how we might save ourselves on our current planet.
Today's excerpt for our November spotlight on excerpts comes from two sections in Dinner on Mars: one discussing the possibility of creating dairy-based foods in an off-earth environment and one discussing the environmental impact of dairy here at home and how technology may one day resolve that crisis.
Excerpt from Dinner on Mars: The Technologies That Will Feed the Red Planet and Transform Agriculture on Earth:
Chapter 6: I Can’t Believe It’s Not Cow
Dairy on Mars will be a challenge. It’s possible that we could take cow embryos along on the ride between Earth and Mars, but the radiation exposure would be terrible for the fetal creatures, and then there is the question of what on Mars the animals would eat when they got there. After all, we are imagining grass will be in short supply.
Like humans, animals in space experience stress and lose weight, muscle mass, and bone density. But even if we could move a few cows to Mars, we likely won’t. A dairy cow eats twenty-five kilograms of feed a day and drinks between 100 and 200 liters of water. On Earth, feeding these creatures represents about 70 percent of the operating cost of most dairies. In a pioneering space flight to Mars, the energy required to take such vast quantities of food and drink — to say nothing of the animal itself — off Earth would crush even the most generous budget. And producing so much food each day just to extract a bit of milk from a large quadruped is utterly impractical. So, the idea that we will ever hear the gentle mooing of Bos taurus as the sun crests on a Martian dawn exceeds even the most fanciful science fiction.
Fortunately for our hypothetical Martians, there are other options. In many ways, the best option has always been to use plants as a substitute for dairy. Replacing milk with plant-derived products — such as almond or soy “milk” — is old technology. The first such product was likely from soy and appeared in China about two thousand years ago. Similar beverages include the horchata of Central America, the boza of Eastern Europe, and the malted millet beverages of East Africa. Most of these alternative milks are traditionally made at home in small batches, but in the 1940s, a commercial soy milk industry developed in Hong Kong, spreading globally in the 1970s and 1980s.
The earliest versions of this product were a bit grim and are remembered by Evan, Lenore, and many other children of the 1970s with a shudder for their gritty texture and “beany” flavor. The first attempts at soy ice cream were both brittle and bitter (not two words usually associated with a nice trip to the ice cream parlor). Since then, however, plant-based “milk” technology has advanced markedly and today it is driven by the popularity of plant-based diets, health concerns, worries over the environment, and — of course — lactose intolerance. Soy milk continues to dominate the market, but cashew milk, rice milk, coconut milk, and even macadamia nut milk all have strong fan bases. In the U.S. alone, the plant-based milk category is worth about two billion dollars per year — or 14 percent of the total retail milk market.
Later, Lenore mused about oat milkshakes and she texted Evan: “I wonder if oat milk will be the dairy of choice for the Martian on the go?”
“Maybe,” he replied, but by this point, he was starting to research growing grain on Mars and getting a bit skeptical. While we think that it is possible a future Martian community may be able to produce a few oats and a reasonable (but modest) supply of oat milk, this won’t suit all the culinary needs of the people of Mars. For one thing, even oat milk struggles to make one of the most popular dairy products of all-time: cheese.
The question of producing decent cheese on Mars can be made simple: Can we take our cumulative understanding of cheese science, umami, and terroir and combine them together to produce good cheese there? After all, despite their tasty versatility, sometimes oats aren’t enough. We want mozzarella that melts and stretches. We want brie with bite. And when we reach for our Stilton, we want it blue. But without cows or millennia-old microbiomes, is that possible?
Answering this means we need to dig into the space-age stuff, and this requires us to shift focus and meet the newest kid on the food block: cellular agriculture (cell-ag). This emerging technology proposes to produce meat and milk but without any animals. Cell-ag refers to a set of technologies that fall into two rough categories. The first is tissue farming, in which meat and other products are grown in an oversized petri dish called a bioreactor (1). The second approach is more like brewing and involves using yeast (or fungus or bacteria) that is modified to convert sugars into animal protein (instead of alcohol or other more common products of fermentation).
Fermentation using genetically enhanced yeasts and bacteria owes its origins to the gene-splicing techniques of Stanley Cohen and Herbert Boyer back in 1973. Cohen and Boyer’s work was initially ground-breaking for medicine, as it led directly to our ability to synthesize insulin using genetically altered bacteria. Synthetic insulin became commercially available in 1982 and causes fewer allergies, has a more consistent quality, and provides a more dependable supply for diabetics, thus saving millions of lives in the past few decades alone. Synthetic insulin was so successful that it launched the entire field of biopharmaceuticals.
But let’s get back to Martian dairy.
It seems almost certain that the future Martian milkshake won’t rely on cows, or even oats, but rather on yeast and bacteria to synthesize the kinds of proteins we normally find in milk. These proteins will then be added to plant fats, water, and trace elements to create the look and mouthfeel of animal-derived dairy. And this technology is already being used in North America today.
For instance, when Perfect Day began selling cell-ag ice cream in 2020, they used a strain of yeast that digests particular sugars and produces milk proteins. In this way, Perfect Day uses a process more like brewing beer than milking bovines. This yeast-derived whey protein is then used as an ingredient in ice cream. Simply mix with water, fats, sweetener, and flavor and, voila: the perfect ingredients for the would-be Martian ice cream parlor where the nearest cow is 114 million kilometers away. Other companies are working on casein protein synthesis and the creation of animal fat through advanced fermentation. Our Martians might have to assemble their cheese like a jigsaw puzzle, but it is likely they will have all the needed pieces.
These technologies will be useful on both Mars and Earth where they are already solving a very cheesy problem. For the past three decades, cheesemakers everywhere have faced a critical shortage of the enzymes found in rennet, which come from the stomach lining of ruminant mammals. This is what makes milk separate into curds and whey, thus helping dairy on its journey from udder to cheeseboard.
As the global demand for cheese has grown, the supply of stomach lining couldn’t keep up, so, years ago, some smart food scientists asked: could a supply of rennet be engineered? Thankfully the answer is yes. Rennet can be produced through a fermentation process very similar to the one Perfect Day uses to make their dairy proteins by employing bacteria, fungi, or yeast to convert sugars into rennet. Synthesized rennet has meant that the cheesemaking industry has been able to match demand. When fermentation-derived rennet was approved by the FDA on March 24, 1990, it was the first genetically engineered product approved for food production.
And the economics work out too: synthetic rennet has become much cheaper than the animal-derived product, and the cheese it creates has been consumed by an entire generation of happy human cheese lovers without any health or environmental problems.
This successful track record of using biotechnology to convince yeast to do the work of animals set the scene for numerous other such products including Perfect Day’s products that received approval from the FDA on April 15, 2020. Their ice cream started to be sold across America as a demonstration of the technology that summer.
Saving Earth with Martian Technology
Both of us were excited about cheese without cows, and not just for application on Mars.
“The environmental potential of these technologies is huge,” Evan remarked as he paced his room.
“Stand still, will you?” asked Lenore, “you are popping in and out of frame. But yes, I agree. Dairy has such a big environmental footprint, especially large-scale dairy.”
This was true. Dairy cows are a poster child for the old saying “too much of a good thing.” Worldwide, milk production was estimated by the United Nations’ Food and Agriculture Organization to be at 843 million tons in 2018, and this is predicted to double by 2050. Unless we radically rethink the industry, the environmental impact of dairy will double as well. And for those of us who are not planning on competing for a spot on one of the first missions to a Mars community, doubling the size and impact of our dairy industry could spell Bad News for the ecosystems we all depend on.
This is because there is ample evidence and data that show in detail how damaging grazing animals can be, highlighting their massive contributions to climate change, air pollution, damage to land, soil, and water, and the reduction of biodiversity. The major United Nations’ report Livestock’s Long Shadow (published in 2006) ranked livestock in the top two or three contributors to these problems, and highlighted that livestock is by far the largest user of the Earth’s land area, equal to 26 percent of the ice-free area of the planet’s landmasses. And of the crops we grow, roughly one-third are used to feed livestock.
Livestock’s Long Shadow’s key conclusions have been validated elsewhere including in the 2018 EAT-Lancet Report, published in the top medical journal of the same name. And while there are many situations where raising animals for agriculture can really help the environment, at a global level, the impact of all our cows, pigs, and chickens is expanding rapidly.
The climate impact of livestock is grim. The industry is responsible for eighteen percent of all greenhouse gas emissions (2). This is partly because there are so many grazing animals now; the biomass taken up by livestock, which is dominated by cows and pigs, is far greater than that of all other wild animals (3). That’s a lot of sirloin.
So maybe even if Perfect Day, and companies like it, never bring their product to Mars, they may help meet our rising demand for cheese and milk in a way that lowers the total environmental impact of the industry here on planet Earth. The company has tallied up the entire impact of their proteins along its life cycle and estimate that fermentation-derived dairy reduces water use by 98 percent, land use by 77 to 91 percent, energy use by 25 to 48 percent, and greenhouse gas emissions by 35 to 65 percent compared with global averages for the regular dairy sector. Given the impact of cows, this is a big deal. And given the feedstock for this process is plant sugar, yeast-derived dairy could even — at some point in the future — absorb food waste from other industries.
Could such a cheese ever go head-to-head with cave-aged Roquefort? Lenore and Evan slightly disagree on this point. Lenore is bullish and thinks that this will happen with time. Evan is a bit more a traditionalist. While he foresees these alternatives gaining a bigger share in the market on Earth — and really being one of the bases of anything to do with space exploration — he can’t see a lab reproducing the full range of tastes that come from 10,000 years of experimentation on Earth.
But maybe Lenore’s optimism is better-founded? Yeast-derived dairy is basically a ferment, and there are certainly ferments on Earth that are dripping with umami and terroir. These include wine, beer, and distilled products like Scotch whiskey. At top-end restaurants such as Momofuku and Noma, their fermentation teams even talk about microbial terroir. So maybe — just maybe — each Martian community might, in the distant future, have its own populations of yeast and bacteria, much as San Francisco boasts its own species of yeast, Lactobacillus sanfranciscensis (4)? If we take along our microbial companion species, the future for umami and terroir on Mars might yet be bright and tasty.
 We will return to these technologies in the next chapter.
 Lenore points out that this means if you are vegan, you can probably fly more often without guilt. You covered off your climate budget by skipping the carving station at the buffet.
 The numbers on this are astounding. Today, there is 0.06 gigatons of humans, 0.1 gigatons of livestock, and 0.007 gigatons of wildlife. Bar-On, Y.M., Phillips, R., & Milo, R. (2018). The biomass distribution on Earth. Proceedings of the National Academy of Sciences, 115(25), 6506-6511. https://doi.org/10.1073/pnas.1711842115
 They owe their distinctive sourdough bread to this local species.
Excerpt taken from Excerpt from Dinner on Mars: The Technologies That Will Feed the Red Planet and Transform Agriculture on Earth by Lenore Newman and Evan D.G. Fraser. Published by ECW Press. Copyright © Lenore Newman and Evan D.G. Fraser, 2022. Reprinted with permission.
Lenore Newman is the Canada Research Chair in Food Security and the Environment at the University of the Fraser Valley. She is the author of the acclaimed Speaking in Cod Tongues: A Canadian Culinary Journey and the award-winning Lost Feast: Culinary Extinction and the Future of Food. She divides her time between Vancouver and Roberts Creek, BC.
Evan D.G. Fraser is the Director of the Arrell Food Institute at the University of Guelph. He is the author of Beef: The Untold Story of How Milk, Meat, and Muscle Shaped the World and Empires of Food: Feast, Famine, and the Rise and Fall of Civilizations. He lives in Guelph, ON, with his wife and three children.