Encyclopedia of Food and Agricultural Ethics

Living Edition
| Editors: David M. Kaplan

Clean Milk

  • Josh MilburnEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-94-007-6167-4_598-1



Clean milk is a name used to refer to milk created by technological means without the need for cows. It must be distinguished from plant-based “milks” – drinks approximating milk made from the likes of soy, nuts, rice, coconut, and so forth – as it aims to replicate dairy at a molecular level. The most notable producer of clean milk is Perfect Day (formerly Muufri), a biotechnology start-up funded by New Harvest, a charitable organization that has also funded research into the development of clean (in vitro) meat. However, home biohackers – including those associated with the US-based Real Vegan Cheese project – are pursuing similar goals. Perfect Day’s milk is set to be commercially launched in 2018, somewhat sooner than even optimistic launch dates for clean meat products.

One might assume that the ethical issues raised by clean milk parallel those raised by clean meat. While this is true to an extent, clean milk requires independent attention, at least because (1) the technology used to create clean milk is very different from the technology used to create clean meat, and (2) different ethical issues attach to the consumption of meat than attach to the consumption of milk.

This entry will first set out the technology behind clean milk and the broad ethical concerns that have motivated or could motivate individuals to support its development/adoption. It will then explore three issues that could be used to support the contemporary dairy industry over a hypothetical clean milk industry. Next will come three issues that may motivate existing critics of dairy to also oppose clean milk. After this will come three challenges to clean milk drawing from wider concerns in the food movement.

Technology and Promise

Perfect Day’s milk is produced using a process far closer to the brewing of beer than the in vitro process utilized by those developing clean meat. Perfect Day’s innovation comes in the use of yeast that has been modified with cattle DNA. This DNA, importantly, has been physically printed based on information sourced from existing scientific enquiry – no living cow is involved. Once printed, the DNA is inserted into the yeast. The yeast – dubbed “Buttercup” – is then mixed with water and plant-based sugars. Fermentation occurs, and, after filtration and the addition of various plant-based nutrients, Perfect Day is left with a highly pure milk, lacking in the hormones, antibodies, blood-serum proteins, and other elements found in many of the products of contemporary dairy farming. Perfect Day’s milk also lacks cholesterol (associated with health risks), lactose (which can be digested by only a relatively small portion of the world’s human population), and bacteria (thus limiting the need for pasteurization and refrigeration.) For more on the science behind the product, see (Perfect Day n.d.; Pandya 2014; Datar et al. 2016.)

This base of clean milk can easily be modified. In principle, the process could also be used to create goats’ milk, sheep’s milk, camels’ milk, and so forth – even human breastmilk. Given the high costs and unsteady supply associated with human breastmilk, the development of bioengineered breastmilk could revolutionize infant healthcare. It would also aid those parents who seek to feed children breastmilk but who cannot provide it themselves.

Perfect Day’s engineers are not the only people producing clean milk, and Perfect Day’s method is not the only way that clean milk could be produced; indeed, New Harvest seeks to “fuel academic research for the many other cell culture techniques” beyond fermentation (Datar et al. 2016, 124–5). Meanwhile, independently of New Harvest, biohackers associated with the hackerspaces BioCurious and Counterculture Labs are utilizing CRISPR, a newly developed gene-editing technique, to create “Real Vegan Cheese.” They, too, use genetically modified yeast to produce milk proteins.

Both Perfect Day and the Real Vegan Cheese project arise ultimately from dissatisfaction with vegan alternatives to dairy products. This gives an idea of why clean milk might be supported. A first concern looks to animals, whether this is framed in terms of animal welfare, animal rights, or some other normative framework. There are over 250 million dairy cattle worldwide (CIWF 2012). Standard Western dairy-farming practices – which are the most productive – see cows forcibly impregnated, with their offspring separated from them shortly after birth. Males and “surplus” females are killed or enter the meat industry. Once cows have reached the end of their optimally productive lifespan (perhaps at around a quarter of their “natural” lifespan), they too are killed. These and associated practices – dehorning, branding, transport, confinement, etc. – raise concerns for advocates of animal welfare and animal rights. Clean milk production, on the other hand, requires no animal input. (This contrasts with clean meat production, which – with current production methods – needs animals for the acquisition of source cells, and perhaps in other ways.)

The contemporary dairy industry also raises environmental concerns. A report from the Food and Agricultural Organization of the United Nations found that global milk production contributed 2.7% of anthropogenic greenhouse gas emissions in 2007, and this was upped to 4% with the inclusion of the raising of “surplus” calves for meat (Gerber et al. 2010). Also significant is the industry’s energy use, land use, water use, and pollution. By contrast, preliminary analysis by the conservation biologist Mark Steer found that, compared “to conventionally produced milk, [Perfect Day’s clean milk] involves approximately 24–84% lower energy use, 98% lower water use, 77–91% lower land use, and 35–65% lower [greenhouse gas] emissions” (2015, 1). These environmental impacts are contributing to damage to the global ecosystem as well as harm to humans and other animals. These environmental concerns, however, are not the only way that clean milk has potential to limit harm to humans: The lower land use speaks to clean milk’s potential as a factor in ongoing discussions about feeding a rapidly growing world population, and it is worth noting that a move away from the antibiotic use of contemporary dairy farming could play a part in stemming the rise of antibiotic-resistant superbugs.

The prima facie case for supporting clean milk is thus compelling; the technology offers the chance for consumers to have milk while limiting their contribution to harm to animals, the environment, and other humans. There are, nonetheless, a range of ethical challenges one could raise.

Clean Milk and the Dairy Industry

Clean Milk and the Ontology of Milk

Proponents of the contemporary dairy industry can be expected to challenge the idea that clean milk is milk. While it is – in principle – indistinguishable from cow’s milk in terms of chemical make-up, taste, and texture, one could plausibly hold that milk needs to have come from the mammary gland of an animal. This dispute is not merely academic. There is political and marketing power in the words “milk” and “dairy,” and this is recognized by the contemporary dairy industry. A parallel debate took place in the European Union in 2017, where a court found that plant-based products (with a few exceptions) could not be sold as “milk,” “butter,” or “cheese.” Similar regulatory barriers exist elsewhere.

A related issue concerns whether clean milk can truly replace the culinary value of dairy. People who continue to use dairy products despite an awareness of the harms of the dairy industry might appeal to the fact that plant-based alternatives to dairy (e.g., soy-based “milk” and “cheese”) have different tastes and textures to dairy products. These culinary values can be replaced by clean milk, so defenders of the contemporary dairy industry will have to appeal to other values. Perhaps such an argument would draw upon a claim about the value of a relationship to animals or the land that milk consumption offers, but the advocate would need to explain how these relationships work, and, if they offer culinary value, in what sense they change the nature of milk qua food.

Clean Milk and the Loss of an Industry

The existing dairy industry relies on both consumer acceptance and governmental support (including subsidies). Like any situation in which consumers shift support from one product to another, widespread uptake of clean milk may mean a change in the kind of work available and a change in the amount of space devoted to the dairy industry and its products – physically, culturally, politically, and so forth. Those who benefit from the existing dairy industry or who conceive of it as a part of their identity are thus likely to be worried about widespread acceptance of clean milk. Perhaps they have reason to be worried, given that New Harvest explicitly seeks a “post-animal bioeconomy” (Datar et al. 2016, 127).

A change to – or elimination of – traditional industries and ways of life is the standard result of social and technological progress. While critics of food biotechnology might want to frame their concerns as part of a broader conservatism, this could involve biting unappetizing bullets concerning other social and technological advancements. If these critics do not wish to frame their challenge as a part of a broader conservatism, some account is owed that identifies the contemporary dairy industry as something particularly valuable and worthy of retention. As with the kinds of culinary value discussed above, such an argument could draw upon some claim about relationships with animals or the land. This argument is, however, a hard sell. It is not clear that contemporary farming practices do involve positive and valuable relationships with animals and the land, and even if they do, it is not clear that the positives of these relationships could outweigh the harms of the contemporary dairy industry or could not be sought elsewhere.

Perhaps locavores and other “compassionate carnivores” will want to challenge clean milk and industrial animal agriculture and call instead for small-scale, local farming, claiming that this farming allows people to have an appropriate relationship with food, animals, and the land (cf. Stănescu 2016). But it now sounds like clean milk is hardly the problem; indeed, Perfect Day expresses support for farmers engaged in environmentally responsible, small-scale humane farming (Perfect Day n.d.), and even some animal rights advocates can allow for a form of small-scale dairy farming – though they will be opposed to the infliction of death and suffering upon dairy cows or their calves.

Clean Milk and the Loss of Animals

If dairy production were to shift from contemporary farming practices to clean milk, there would be fewer cows in the world. From an animal rights or climate ethics perspective, this is almost certainly a positive. Other kinds of accounts, however, can frame this in a different way. If we assume that dairy cows live minimally happy lives, and we assume an account of population ethics according to which we can be obliged to maximize the creation of happy lives, it could be that we are wrong to support clean milk because in so doing we fail to create many happy lives.

This kind of worry has a place in the animal ethics literature. It is associated strongly with so-called total utilitarianism, though the position is not one that has many vocal advocates (or, minimally, the conclusion that we should be creating many happy lives is one that has few vocal advocates). This argument against clean milk can be challenged on several grounds. First, and most importantly, these accounts of population ethics invite many problems – including the infamous “repugnant conclusion.” Second, it could be that dairy cows do not live minimally happy lives. Third, there are any number of other consequences that need to be considered, along with other possible policy proposals. For instance, continued societal support for dairy industry may result in widespread harm in the medium term (through climate change, public-health effects, and so forth), and land currently used for dairy production could house many wild animals. Indeed, if we are serious about maximizing happy animals, perhaps we should convert existing dairy farms into spaces for housing many happy (say) hamsters.

Clean Milk and Opponents of Dairy

Milk and Respect for Animals

Many vegans and animal advocates will be uneasy about the development of clean milk as it perpetuates the idea that milk is food for humans. Rather than finding replacements for milk, these advocates might argue, we should be challenging the centrality of milk in western food systems. It could even be claimed that the consumption of milk(-like products) is inherently wrong, regardless of sourcing. These kinds of arguments have been suggested when it comes to clean meat (Miller 2012), and while one could affirm such arguments in the case of clean meat while rejecting them in the case of clean milk (Sinclair 2016, 230–3), it could be that all animal foods and their imitations should be challenged.

The obvious response is to claim that there is nothing inherently wrong with consuming animal products and that such consumption only becomes wrong when it contributes to harm to animals. The critic of milk consumption per se could in turn claim that the consumption of milk does involve harms to animals; disrespect, perhaps, or a contribution to indirect harms.

A slightly different approach to the wrongness of milk consumption would draw upon the vegan slogan that as the cow is “not your mother, [what she produces is] not your milk,” or the idea that milk is food for calves, not for us. Starting with these ideas, one can affirm mothers breastfeeding children while condemning other forms of milk consumption. Generalizing these slogans into ethical principles may result in some surprising conclusions when it comes to examples of intuitively innocuous and autonomous milk sharing in human culture and history – including interspecies milk sharing. But these bullets may not be so hard to bite.

It is worth noting that the defender of clean milk could appeal to the product as a “least worst” or “non-ideal” alternative to the current milk industry. Perhaps, it could be said, no one would consume milk in an ideal world, but – as we do not live in an ideal world – we should be ready to offer lukewarm support for clean milk, not least as it offers an alternative to the contemporary dairy industry in which (certain egregious) harms to animals are removed.

Milk and Race

The centrality of milk in Western food culture – and especially the centrality of milk in Western dietary advice – has been framed as problematically ethnocentric, as large proportions of the world’s population have “allergies” to dairy (see Gaard 2013). Claims about milk and lactose intolerance have motivated even found a place in racist rhetoric. This opens the door to concerns about milk completely independent of the kinds of concerns (animal welfare/rights, the environment, etc.) that have motivated and will motivate the development and uptake of clean milk. The technology, nonetheless, may be a valuable one for developing forms of milk that are accessible to those peoples who tend to be unable to digest milk; versions of milk could be, and are being, developed that do not contain the problematic components.

Milk and Health

Certain advocates of plant-based food eschew milk because they perceive it as particularly unhealthy. Depending on their reasons for believing that milk is unhealthy, they may perceive clean milk as unhealthy. Those who hold that milk is inherently (or overwhelmingly) unhealthy might even advocate for sales restrictions on milk – clean or otherwise. For example, they could argue in favor of the inclusion of warning labels, the banning of the sale of such products to children, or the removal of these products from schools. Such arguments would rely not only on contentious ethico-political claims about the reach of state paternalism but also contentious empirical matters about the healthfulness of milk.

There are reasons to believe that critics of the healthfulness of milk produced by the current milk industry might be open to clean milk. Clean milk products will lack certain impurities and additives that can be found in the products of the current milk industry (hormones, antibiotics, etc.) and can also be modified to add or remove other components – for example, Perfect Day’s milk lacks cholesterol. Whether this possibility will open these health-conscious consumers to clean milk will depend on what it is about milk that worries them in the first place.

It is also possible that people will perceive health risks with clean milk that they do not perceive with milk produced by the current milk industry (cf. Laestadius 2015). This is a common response to new technological developments – while producers of clean milk certainly have an ethical responsibility to ensure that the product is a safe one, it is likely that this presents more of a marketing challenge than a genuine scientific or ethical issue.

Other Concerns

Clean Milk and GMOs

The production of clean milk (unlike, incidentally, the production of clean meat) involves genetic modification. Though it is only the yeast that is genetically modified – the final product is GMO-free – consumers with a principled objection to GMOs are likely going to be unimpressed by clean milk. Consumers with a more nuanced approach to GMOs are unlikely to be worried by clean milk, as its production requires genetic modification only in the most controlled and contained environments.

Clean Milk and Capitalism

One challenge that has been made to the production of clean meat is that it potentially shifts control of food production into the hands of corporations (Miller 2012). This kind of thought might be deployed in criticism of clean milk – especially while there is only a single company utilizing the technology commercially. One counter-thought points to the idea of democratizing clean meat production (Weele and Driessen 2013), and this, too, is possible when it comes to clean milk. Indeed, Perfect Day, New Harvest, and the hackerspaces supporting the development of Real Vegan Cheese all have strong commitments to open-source information. Given the motivation of many of the people involved in these projects, it would be counterproductive for them to limit the spread or uptake of the technology. For Bruce Friedrich, of The Good Food Institute – a second leading not-for-profit concerned with clean animal products – “the more researchers in the space the better, as they will leverage one another’s knowledge and bring increasingly better products to market faster, at a better price” (Bhumitra and Friedrich 2016, 199).

It is undeniable that Perfect Day – like many biotechnology start-ups – exists in a context of venture capitalism. Critics of contemporary capitalism, of course, are likely critical of this model. It is also undeniable that the development of clean milk has taken place in the context of a consumer-choice model of food distribution, and it is likely to thrive or fail in that context. Again, committed critics of capitalism may challenge this model, though it is hard to see why they would have any particular quarrel with clean-milk producers.

Clean Milk and Naturalness

Perhaps the greatest challenge clean milk is likely to face when it comes to consumer acceptance is the idea that producing milk using genetically modified yeast is problematically “unnatural.” This is certainly a concern that has been seen in the public response to clean meat (see, e.g., Laestadius 2015), and – though there is no published research on public perceptions of clean milk – it is likely that similar concerns will be raised.

These kinds of naturalness worries are common in discussions about the ethics and philosophy of food and are notoriously problematic. An account is owed of what makes something “natural” and in what sense something being “natural” is a good thing. Even if these problems can be overcome, naturalness arguments are not an easy friend to animal agriculture. Presumably, one must weigh the “unnaturalness” of clean milk against the “unnaturalness” of contemporary agricultural practices. One must also weigh the “unnaturalness” of clean milk against the benefits of clean milk, and this includes the benefits that clean milk could provide to the “natural,” including the preservation of “natural” environments (in contrast to how these environments would fare were the contemporary dairy industry to continue unabated). Again, it may be that naturalness objections present more of a marketing challenge than a genuine ethical hurdle to overcome.


Clean milk presents an alternative to milk produced by animal agriculture, allowing people to have the nutritional and culinary benefits of milk without the harmful effects of the dairy industry – to animals, the environment, and humans. Though it will soon be commercially available, it has received little academic attention.

It can expect to be challenged by apologists for the contemporary dairy industry, who may challenge its status as “milk,” lament the harm it could do to the dairy industry and ways of life associated with it, and perhaps question the ethics of creating fewer cows. It can also expect to be challenged by certain critics of the contemporary dairy industry. For some vegans, it will not go far enough – for them, the consumption of dairy will always be wrong. Others may worry about the healthfulness of milk as such and may raise worries about the interplay of milk and race/racism. Other kinds of challenges might include worries about the use of genetically modified organisms in the food industry, the control of food distribution by capitalist interests, and the “naturalness” of certain food production methods.

Defenders of clean milk have an array of arguments at their disposal to respond to these challenges. Ultimately, however, the success of clean milk is unlikely to come down to close argumentation in academic journals and instead to the messy and irrational world of consumer acceptance. It is not ethicists who will determine the success of clean milk, but marketers.



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© Springer Science+Business Media B.V. 2018

Authors and Affiliations

  1. 1.Department of PoliticsUniversity of YorkHeslington, YorkUK