The Dawn Of Synthetic Milk: When Milk Becomes More Like Beer

What would we do without milk in modern day society? Although lactation originally evolved as a way to provide a newborn mammal with nutrients and the other essentials during the first weeks of their life, milk has for thousands of years now been a staple food in human cultures. Whether from cows, camels, sheep or other mammals, each year humans consume many liters of this mythical substance, with our galaxy’s name – the Milky Way –  coming courtesy of Greek mythology and a spilled milk incident.

A major issue with mammalian milk, however, is that it is only produced by females for a certain time after giving birth, which requires for example a dairy cow to constantly go through pregnancies, which is both cumbersome and not very animal-friendly. Simultaneously, the newborn offspring cannot drink this milk, but must be provided with an alternative. For these reasons synthetic milk is becoming an increasingly more popular animal- and environmentally-friendly alternative.

For years now, companies such as US-based Perfect Day are producing milk that’s for all intents and purposes identical to cow milk, with the added advantage of being free of lactose and other problematic additions. The best part of this all? It’s all done with existing fermentation techniques.

Bubbly About Fermentation

The production of proteins in a cheap and efficient manner has been one of the triumphs of the 20th century, with success stories like insulin, the hepatitis B vaccine and chymosin all being produced using industrial fermentation that employs recombinant DNA with bacteria, yeast and fungi. These single-celled organisms are grown in bioreactors where they absorb nutrients from their environment, and use these to create the proteins which are encoded in the newly inserted DNA. Once enough of these proteins are created, the contents of the bioreactor are sent off to be lysed. This breaks down the cells, freeing the intracellular proteins for further processing.

Originally, replacement insulin for diabetes patients was extracted from animals. Since the 1980s, modified E. Coli bacteria are now producing virtually all of the world’s insulin supply. Similarly, chymosin is a key part of rennet, the collection of enzymes that is essential in the production of cheese and related products. Originally this substance was usually extracted from the stomachs of butchered calves, but thanks to recombinant DNA, bacteria can also produce this enzyme. These days, over 95% of cheese produced in the US uses rennet from bacterial sources.

The recombinant hepatitis B vaccine from modified yeast replaced blood-derived vaccines, and over the past years the Impossible Foods company has made waves with its use of modified yeast that produces leghemoglobin. This is similar to hemoglobin as found in animals, and adds to this company’s meat-like products like its Impossible Burger.

When it comes to industrial fermentation, we distinguish a number of types:

  • Biomass production
  • Extracellular metabolites (e.g. alcohols)
  • Intracellular metabolites (proteins)
  • Substrate transformation

The fermentation process as we know it from brewing beer, creating wine, bread, yogurt and other types of fermented food is the second type (extracellular). Sugars are used by the microorganisms and converted to the alcohols, acids and other target chemicals that change the properties of the input materials into the desired product. In the case of insulin, vaccines, and other types of protein production we use the third type, with intracellular production of the desired protein.

In order to apply the same approach to synthetic milk, we have to identify the protein(s) so that an encoding DNA sequence can be inserted into a microorganism .

Milk Proteins Without The Animal

Milk is defined as an emulsion of butterfat globules within water-based fluid, containing carbohydrates, proteins, vitamins and minerals. The proteins found in milk are both the whey proteins (like β-lactoglobulin) and the caseins (like K-casein) that form micelles: aggregates of thousands of these proteins. The Perfect Day company focuses on β-lactoglobulin, as it’s the main whey protein in mammalian milk. Whey is a byproduct of cheese production, and has many commercial uses.

Whey proteins aren’t the only option here, of course. As recently reported by The Guardian, a number of start-up companies are seeking to produce the full milk product, including the whey proteins, casein proteins and the other elements that provide milk with its characteristic properties and taste. Of the 20+ proteins in cow’s milk, most are casein proteins, with the casein micelles playing a key role in the thermal stability that enable its use in hot drinks.

Australian start-up Eden Brew is looking to use recombinant yeast to produce six of the most common milk proteins, with plans for an ice-cream in 2023, followed by plain milk by 2024. This is indicative of the biggest challenge in this new industry: namely scaling. For each protein added you need to maintain the recombinant strain of the microorganism, set up its own production line of bioreactors and processing equipment and provide these bioreactors with nutrients.

Even though the general process is similar to that of insulin, the sheer scale is a few orders of magnitude larger, since not only do about 80% of the world population consume milk, they also do so on a scale that’s far beyond the relatively small amounts of insulin produced in these bioreactors annually. Scaling up the production facilities and setting up a supply chain will take time, but the benefits of doing so would be astounding. One only has to picture the number of animals needed to produce insulin today if we had not created recombinant insulin to get an idea of the sheer scope here.

Cut The Cow

A good perspective on the environmental footprint required by cow’s milk, as well as a number of plant-based alternatives is provided by Our World in Data in the form of the following chart:

What this chart tells us is that although cow’s milk scores pretty poorly on environmental metrics, plant-based alternatives come with their own sets of trade-offs. Here synthetic milk offers a tantalizing new option: since it is produced in bioreactors by microorganisms, the land use is minimal, with the other parameters limited by the source of electricity and nutrients for greenhouse gases, as well as the overall filtration and water recycling ability of the facility that houses the production lines.

Another important aspect here is that of monocultures. For dairy cattle, large stretches of pasture are required, while for plant-based alternatives large croplands are used to grow just soy, rice, almonds, etc. A bioreactor facility would avoid the pesticides, fertilizer runoff, and greenhouse gases of natural milk production.

Whey To The Future

One thing that synthesized milk definitely has going for it is that it doesn’t necessarily do anything new. Using techniques pioneered as far back as the 1970s in the medical field, we have now reached a point where we can modify microorganisms to produce proteins easily and consistently. Even if buying a liter of synthesized milk off the shelf at the local grocery store is still a few years off, whey proteins are already being produced this way, displacing at least part of the demand from cow’s milk.

Although the milk consumption per capita has remained relatively constant since the 1960s, the world population has increased by a few billion (3 billion in 1961, 8 billion in 2022), which means a corresponding increase in demand for milk. Even if synthesized milk won’t outright replace cow’s milk and dairy farms along with it over the coming years, maybe it can make a useful dent in the increased demand.

It seem reasonable to conjecture that as the supply chains for bioreactors and related equipment for such large-scale industrial fermentation ramp up, synthesized milk producers might just begin to not only supply the ice-cream and baked goods markets, but also push into the regular milk market. A lot here depends on how fast and how cheaply this can be made to scale.

At the very least there definitely is no lack of start-ups, with in November of 2022 US-based New Culture announcing its mozarella cheese made using synthesized caseins. Much like the Impossible Burger with its leghemoglobin protein from yeast, this makes it a vegan option since no animal was involved at any stage of the production, which is an aspect that for example cell culture meat struggles with.

Whether this will be enough is hard to say at this point, but with approved products on the market available today and more in the pipeline, some optimism would seem warranted. Even if some will definitely want to argue whether synthesized milk is even ‘real’ milk.


85 thoughts on “The Dawn Of Synthetic Milk: When Milk Becomes More Like Beer

    1. They’re called “milk” because nobody would drink them if they were called “inferior mashed plant juice that looks sort of like milk but isn’t” no one would buy it.

        1. Well according to the article nuts produce far less GHGs than milk, so why don’t you eat my… but really it’s not milk and calling it milk is just false advertising, like calling tofu “Soya meat”.

          1. It’s called “soy milk” so people understand how to use it (e.g. put it on your cereal). It’s not to trick consumers into accidentally buying it instead of the cows milk they wanted. Not once in my entire life have I met anybody so dumb that they made that mistake.

        2. The people who collect and push that data are heavily infested in industrial monocropping and synthetic foods. Which is AWFUL for the environment, I don’t care what their “data” say.
          Animal husbandry has been practiced for tens of thousands of years. You people need to learn to detect greenwashing. Are we doing bad things to the environment? Yes we are. But stop trusting the people who did in in the first place after they do a big PR spin to make themselves out to be the good guys (and they’re liquidating the kulaks/their competition at the same time as a bonus!)

          1. Infanticide was practiced for tens of thousands of years, so that’s not much of a standard. Like many other things human beings have done up to this point, animal husbandry can only scale so far – humans and our livestock are 96% of mammal biomass. So while we may initially find ‘fake’ milk or vat-grown ‘meat’ bizarre and unappetizing, it beats starving…

    2. If it looks like milk and is used like milk, why is it such a problem for you?

      If you go shopping for (cow) milk and you accidentally bought goat milk, you would be pissed too. But I doubt that you complain about goat milk being called goat milk?

      Luckily, the package will clearly say “goat milk”, just the same way as the package will say “oat milk”, “soy milk”, or “whatever milk”.

  1. Whey might be the last component they look to specifically synthesise – I recall that most whey is binned as a waste product of the cheese industry. Well, probably into generic animal feed stock rather than ‘binned’.

    These processes are proteins specifically, no? We could get the protein content of cheese this way, but we’d need a different process to get dairy fat?

    Anyways, cattle are outrageous for greenhouse emissions. From memory, 90% of energy in comes out as methane.

    1. Whey WAS a waste product decades ago. Nowadays whey is nearly everywhere, usually in the form of spray-dried whey powder. It is primarily used as a cheap filler and has partially replaced expensive milk powder. You can find it in chocolate, cookies, bread, instant drinks and lots of other foodstuff. If the supply of real whey dries up for whatever reason, the food industry needs a cheap substitute for a cheap substitute.

      1. So hypothetical for you – what happens when your all-natural waste product dumping pond is such a nuissance to the surrounding neighbors that the DEC fines you?

        The cheese company I work for invested in a reverse osmosis system to concentrate the whey protein enough to make it economical to ship it out in tankers to be spray-dried. Stupidly expensive, inefficient, and I highly doubt we make any money off of it, but it beat getting shut down.

    2. Then please do everything possible to reduce your own flatulence. And, the cow-methane line is pretty damn tired for two reasons: People keep leaving vehicles idling, and changing feed reduces methane production with cow farts.

  2. I’ll tell you what will happen over the coming decades, the rich will continue to enjoy high quality organic animal based products and the poor will live off what comes out of factories. If we have a volcanic winter (again), and don’t shut down completely due to the folly of running our civilisation on solar power, then everyone will have to survive off the factory food, rich and poor.

    1. You’ll get to eat factory-made food? You Lucky, Lucky Bastard!

      Most of us will be forced to eat bugs. “And we’ll be happy.”

      The richest will never have to eat factory food or bugs.

  3. Anyone else with a chemistry background bothered by this story’s illustration missing proper heat and coolant sources? Or is that a tacit disbelief in this process ever working?

  4. You left out some really good upsides to synth milk: it lasts MUUUCH longer. Normal milk goes sour fairly quickly, so if you use it infrequently it’s not a great product. I know oat milk doesn’t even need refrigeration. The other upside is that it’s much lower in sugar which is exceptionally high in US milk. Sugar is OK in moderation but cows have been bred to make crazy sweet milk. Synth milk gives you the choice of reducing your sugar intake.

    1. I looked up the sugar content of US milk and whole milk here in Germany. Both official sources state it’s around 5g/100ml milk sugar / lactose.

      I wouldn’t call 5g/100ml “crazy high”. Especially compared to other sugar-bomb drinks in the shelves.

      1. You’re also drinking rapeseed oil. It’s utter garbage, really bad for you. A while ago it wasn’t considered fit for human consumption. It was paint thinner. Then some chemist figured out how to make petroleum-based paint and so the industry shifted to pouring it down your gullet. Avoid it.

        1. Rapeseed / Canola varieties used for consumption are bred to have acid levels that are safe to eat. It’s not a spectacular oil but it’s really just a vegetable oil and eating it is more of an opportunity cost (you could be using a good vegetable oil, haha) rather than something unsafe.

      1. The taste of UHT milk is unbearable for me.

        The best thing I ever tasted: microfiltrated milk. Better tasting and longer lasting than pasteurized milk. That was 20 years ago and I thought it was the future of milk. I don’t know why it didn’t catch on.

          1. Yeah, they’re called Americans. Ultra-pasteurized is common around here, which is cooked at a higher temperature than conventionally pasteurized, but I haven’t seen room-temperature UHT milk even at Whole Foods. (Room-temperature cream or half&half, yes.)

  5. “For dairy cattle, large stretches of pasture are required, while for plant-based alternatives large croplands are used to grow just soy, rice, almonds, etc.” The fermentation approach requires some kind of feedstock – it’s not gonna be free.

    1. >The fermentation approach requires some kind of feedstock – it’s not gonna be free.
      Let them ~~eat cake~~ drink TRASH!
      Supercritical Water Reactors have been employed in breaking down Lignocellulosic mass into simple sugars for the production of ethanol. When this technology is perfected and scaled up it would be perfectly fit for generating feedstock from cornstalks, sawdust, cardboard, etc.

      >Supercritical conditions of water are reached at 374°C and 221 bar. Above these conditions, the dielectric constant of water decreases, increasing the solubility of organic compounds in it. At 250 bar and between 300 and 400°C, its ionic product ranges from 10–10 to 10–22, enabling enhanced selectivity in chemical reactions and changing the ionic reaction mechanisms to free radicals. In addition to these improvements in physicochemical properties, there is no need to dry the biomass before treatment, and the resistance to mass transfer is reduced or even eliminated (Cantero et al., 2015). However, the use of this technique requires extremely low reaction times to avoid C6 (glucose) and C5 (xylose, arabinose, etc.) sugar degradation, limiting its application to ultra-fast reactors with residence times of only 1 s (Cantero et al., 2013).

    2. The issues are with land use change, eutrophication, pollution from pesticides and manure, biodiversity loss and GHG emissions. If you can feed the microorganisms whatever, you solve a lot of the problems. It should also be much more efficient because you don’t need most of the resources to go into “keeping the animal alive”.

      1. The Saudis grow alfalfa in the desert (Arizona?) to feed their dairy cows. A 747 cargo plane hauls the alfalfa to Saudi Arabia.
        Locals are complaining that the aquifer levels are decreasing.

  6. Another thing missing is that modern day milk cows make waaaay more milk than their offspring could ever drink anyway, so there would still be milk available for harvest if they wanted to let the offspring nurse.

    Also, is the ‘repeated pregnancies’ statement true? I know in human females, a woman will continue to produce milk for years after a single pregnancy so long as the demand persists. Is the same not true for other female mammals?

    1. Yes, cattle have been bred to overproduced milk, but anything a calf uses can’t be sold.

      Yes, repeated pregnancies are the norm in milk production. After a while production drops off. If you get the cow pregnant again, on birth production volume jumps. (that’s awkward phrasing. The cow doesn’t get milked throughout pregnancy, they get fallowed then preggo then milked.) It works the same in humans (all mammals afaik).

  7. We already have milk that last much longer: ESL milk (1 month @ 5°C), UHT milk (3…6 month @ 25°C) and milk powder (>1 year @ 25°C). All liquid variants, including non-dairy substitutes, will turn bad within a couple of days once the container is opened.

  8. I’ve been using flavored-soy-water to wet my cereal for a while, and it works fine for that. No need to engineer anything more milk-like for that, and as others mentioned, it keeps way longer without spoiling. I could never make it through a whole quart of real milk without it turning.

  9. honestly i just dont drink the stuff. milk itself is almost as disgusting as its synthetic alternatives. though i do use it for cooking and i also like cheese, ice cream, and a few other dairy products.

  10. Always bothers me when ‘oat-milk’ or any of the nut-milks are compared to dairy – fundamentally different things, that have wildly different nutritional values. You also have to consider what the raw ingredients are – those nuts and oats can be eaten directly, roasted, etc – they are already right off the plant minimal processes away from being human food. So the question when dealing with how ecologically sound it is then becomes just how much of that nutritional value is wasted turning them into milk like beverages?

    Dairy has its flaws, in some places around the world at least the volume of cow is bonkers, and they too are being fed stuff we could eat bought in cheap from ‘who cares where’ poorer nations with lousy farming practices. BUT sensible dairy (and meat production in general) practices turn lots of plants we can’t digest, that are likely being grown on the fields as part of the required crop rotation for soil health, or grow wild in places less suited to arable farming for one reason or another into a useful food source. All while being part of keeping the soil fertile, the ecology of the region stable etc…

    No denying the lifestyles of many will have to change if a population this large is to be supported sustainably, and even more so with some degree of equality. But its rather more complex than all animal product substitutes are perfect solutions all the time, for all things.

  11. Yeast is a eukaryote just like you and me. It is just single celled. So, do vegans not consider single cells animals? By a numbers game killing one cow vs killing a kajillion independent animals (yeast) is tough math.

    1. Yeast is not just like you or I, it’s not an animal. It’s a fungus, and as such, is totally vegan friendly. While I agree that veganism and artificial foods are preposterous, at least understand what you’re saying before making a bad-faith argument.

      1. It is a good faith argument. I’m not vegan. Just a research biochemist and molecular biologist. For yes or no arguments, the gray area in between is where the interest lies. I have no dog on the fight.
        But to play along- how does a vegan (or
        you) define “animal”?
        Is a fungus not eukaryotic?
        I’m genuinely interested in the argument if not scientific then philosophical.

          1. I have known several vegan’s that won’t eat honey for the same reasons they won’t eat milk or eggs. I don’t believe that standard applies to vegetarians (if the animal wasn’t killed that produced the food item, then you can eat it.)

  12. @Maya Posch said: “A major issue with mammalian milk, however, is that it is only produced by females for a certain time after giving birth, which requires for example a dairy cow to constantly go through pregnancies, which is both cumbersome and not very animal-friendly.”

    Nonsense. Dairy cows are built to constantly go through pregnancies; and ages of field testing proves they perform precisely as expected, which is very good indeed. Did you poll a bunch of dairy cows and from their responses determine their life was “cumbersome” and “animal-unfriendly”? If so, where is the raw data and peer-reviewed results? C’mon man, show it to us!

    1. I worked as a hand on a Jersey cow dairy farm in the pacific north west for a few months while covid politics kept yanking jobs out from under me. Those were some of the more pampered animals I’ve encountered. Had their own couches, got rub downs, played a lot.

      It was an unpasteurized raw milk set up which I had to say made me a little uneasy at first, but those folks know their business. The owner was a organic chemist/biologist with multiple degrees from University of Washington. She’s been tracking and breeding the genetic lines to produce specific types of milk protein. They’re hyper clean and zero waste facility which I thought was pretty awesome.

      I learned more about chemistry talking to her while pitching hay and washing down equipment than I ever did in high school. I also learned about the rather brutal nature of milk and dairy farm politics. Which convinced me dairy farming was not a career path for the faint of heart

  13. Reminded me of a story I’d read a long time ago and recently came across again:
    “Hi Diddle Diddle” 1959 by Robert Silverberg (originally using the pen name Calvin M. Knox). The full text can be found online, with a little searching. The story is a perfect fit for the Hackaday mentality.

    It starts with a researcher on a moonbase in far off future of 1995. Tired of the powdered milk and “synthetic food” he daydreams of a nice glass of fresh milk. Hijinks ensue, resulting in a huge collection of bioreactors and incubators to feed artificial blood to a vat-grown collection of cow udder cells.

    Fun Story, worth a quick read if you can find it.

  14. “Milk is defined as an emulsion of butterfat globules within water-based fluid, containing carbohydrates, proteins, vitamins and minerals.”
    That’s only true for pasteurized milk. Raw milk also contains a live bacterial culture. This help digest the milk. I worry that the synthetic version will leave out these beneficial bacteria. Another thing that’s important with milk is that it is tasty and you can cook with. If synthetic dairy isn’t tasty and isn’t a perfect substitute in recipes it is not very useful. Milk is affordable and delicious and climate alarmism is debunked, so I don’t see a reason to switch to the fake stuff.

  15. All of these anti cattle farming efforts don’t take into consideration the fact that large ruminants such as bovines are a part of the natural ecology. We are able to raise cattle in such massive quantities because bovines have always roamed the great plains, and so the natural environment across most ranches suits the domestic cattle as well as it did to their wild ancestors. Factory farming is a problem, but this just replaces it with another factory process.

    My question to the researchers: if you spend all the time and effort to make synthetic products to completely replace the use of cattle, what’s the plan for caring for all the cattle that are still roaming around? We can’t exactly just let them all loose, they’d wreak havoc on infrastructure so they need to be fenced in no matter where they go.

    1. FWIW the natural environment was bison (in the US) roaming the plains. Cows don’t have the physiology to roam, as much as they’ve been bred, and what the prairie environment needs is specifically massive bunches of bison churning it up and pooping in the result. So while letting all those cows go and removing all the fences would be a very very small step in the right direction it’s nowhere near enough to get close to the natural ecology that was here.

      1. >Cows don’t have the physiology to roam
        A Healthy herd can cover a distance of 15 miles in a day during a hard drive. Left to their own devices cattle will wander as far as they are allowed. Its all the fences that keep them from wandering….and those only KINDA work. A young cow can clear a 5 foot fence,
        Bison only covered 2-3 miles a day typically roaming around 200 miles a year.
        Similarly, when you discover ones wandered off your search is a 2mile/day radius since last count.
        Cows arent some DERPMutant. They are optimized bovines.

        we currently have ~94 million cattle in the US, versus the estimated 30-60 million bison that once roamed. So we actually have plenty of cows to pull off the repopulation of the plains.

        Not that I agree with your assumption of worth in doing so.
        Restoring natural ecology would be a disastrous decision for humanity. We cant support our numbers as hunter gatherers.

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