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A plastic made from milk that vanishes in 13 weeks

https://www.sciencedaily.com/releases/2026/02/260227071922.htm
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Milk is surprisingly intensive in terms of greenhouse emissions. It is somewhere around 1 to 3 kg CO2-equivalent per kg of milk.

Milk protein costs around 95 kg of CO2-equivalent emissions per kg of protein, which is apparently what was used in the production of this plastic [1]

[0] https://www.sciencedirect.com/science/article/pii/S002203022...

[1] https://ourworldindata.org/grapher/ghg-per-protein-poore

It's possible to use manufacture whey protein without cows:

https://en.wikipedia.org/wiki/Whey_protein#Microbial_product...

It's not theoretical either. You can buy vegan dairy products made from this method today.

I'd be interested in knowing what the CO2 emissions were from these. You still need to feed the yeast, so you'll have the CO2 emissions involved in growing a crop associated with this. And if you look at the chart in the OP, you'll see that grain production is about half the CO2 emissions of milk. That's likely part of the milk CO2 production accounting.

In addition, you'll need more cleaning/sterilization/mixing. I'd guess that it's lower, but I wonder how much lower.

And then there's the other products that generally get thrown into the mix to make up for things like missing fats. For example, a vegan cheese based on bacteria will often include coconut oil, probably to get the same fat profile.

Whey is an interesting product in general because it's a waste product of cheese making.

It’s likely to be vastly better.

Feed efficiency is critical when doing these calculations as cows inherently need energy to survive not just produce milk. As such even if you use the same crop two different sources of protein can have wildly different levels of CO2 emissions embedded in their creation. https://en.wikipedia.org/wiki/Feed_conversion_ratio

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But we can also produce milk from yeast now. Perfect Day, for example, produces milk without cows.

So it's not out of the question we could scale that up to meet plastics demand.

I remember when people still knew what milk was ... and what was not milk.

That was before multi-billion-dollar companies came up with marketing strategies that manipulated people into not understanding what milk was, instead making them believe that milk is whatever they tell people.

Usually, the reaction to this is "Well, language and the meaning of words change." ... Sure, but that argument comes in complete ignorance of the fact that it only happened, because people with too much money and power can manipulate millions into believing whatever these millions of people are supposed to believe.

Thus now anything can be milk, as long as some profit-oriented company decides that people shall call it milk.

This practise has become the norm to a degree that people will not only generally accept it, but also generally defend it. Pure madness.

Language changes. In this case just the spelling though.

"Almaund mylke" is all over medieval cookery manuscripts, among other options.

We’ve been using milk for non-animal products for longer than we’ve spelt milk with an i, and for longer than we’ve had companies, let alone multi-billion-dollar ones.

To be clear, Perfect Day doesn't make "milk" like plant-based milks (think almond "milk", oat "milk", etc). They bioengineered some yeast to grow whey protein directly. The milk they make (made?) probably wouldn't be considered "milk" in the strict sense (they had to get the fat and sugars from plants), but there's really not a good reason to distinguish between "whey protein from cows" and "whey protein from yeast" when it's the same stuff.
You understand that the product I'm talking about is the same proteins as milk, and is essentially whey, right?

I'm not talking about grinding up nuts or grains and calling it milk, I'm talking about engineering yeasts to literally produce the proteins that milk has to create a product that isn't just milk-like, but is literally identical proteins.

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The large diary producers are forcing things that everyone understand what is — “Oat milk” and “Almond milk” — to be called “Oat drink” and “Almond drink”. New terms for things that have existed for decades.

Really, we should be calling the OG milk “cow milk” and let the good times roll.

Big milk have been pushing questionable health research and narratives for cow milk for quite some time.

All this coming from someone (me) who drinks 0,5L of cow milk every day.

Yes, yeast milk is milk too. Just like coconut milk.

I thought the reason things are called "Oat Drink" versus "Oat Milk" is because non-dairy "milks" have to be fortified with vitamin D and calcium and the stuff that's labeled a "drink" is not fortified.
The first documented use of the word coconut milk in English dates from 1698 ( Philosophical Transactions of the Royal Society, volume 20, page 333) and the use of almond milk goes quite a bit further back, to at least 1390 (The Forme of Cury).
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But to put this in context, the average American family’s carbon footprint per year is roughly 50,000 kg, and one flight is usually on the order of >1,000 kg, or ~300kg/700 pounds of milk, assuming that 3kg CO2 per kg milk high end figure. So if you like milk, there are probably other places you can cut first.

Does seem like a lot of carbon for a kg of plastic, though, how does that compare to normal plastic’s carbon footprint?

>... >1,000 kg, or 700 pounds of milk

Why do you mix your units like that.

Because I'm American, so I use metric in scientific contexts, and weird medieval units in everyday ones :-)

I'll edit a bit for clarity for you all who live in more consistent places.

Where are these emissions coming from? For instance, if this is counting the emissions involved in logistics, none of that inherently or necessarily requires greenhouse emissions—you can electrify trains, tanker trucks, and refrigerators.

If this is counting the methane emissions of the cow itself, that’s not a fair or complete accounting. The cow produces methane in her digestive system after eating grass, and the grass grows by, among other things, extracting CO2 from the air. Then the cow burps methane, the methane combines with atmospheric oxygen and breaks down to CO2 and water, and you have a closed loop; the cow cannot belch more carbon than she eats, and that carbon came from the air in the first place.

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I’m hoping this is a first step toward using some other protein(s). There are some fairly high protein plants like chickpeas and soy that are less intensive to produce than milk.
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> Plastic production has climbed from 2 million tonnes in 1950 to 475 million tonnes by 2022, roughly equivalent to the weight of 250 million cars.

That's 60 kg/person/year of plastic, which is a lot. Or about 4800 kg for a person living 70 years. Obviously, there is wide variation in this number across the human population.

Worth noting that casein is a very very old technology - people have known how to use it (well, milk) to make a type of glue for thousands of years.
Luckily, producing milk is completely environmentally friendly!

/scnr

The paper doesn't talk about thermal properties, which is a shame. Would be good to know if this is a thermoplastic.
sounds like bakelite to me. you can get a disposable polymer from polylactide as well, and it can be obtained from silage (so-called green refinery, although the term seems to have been broadened in the last decade)
PLA is also biodegradable and cheap but it does not biodegrade that fast, certainly does not vanish in 13 weeks. Im not sure what the usecase is here but I'm sure it could have some uses.
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New subscription model coming to plastics! Products last only 13 weeks.

I know - long lived plastics are bad. We need some kind of middle ground thats as cheap as the current plastics and doesn't last as long.

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How long before a bacteria learns it can eat this and starts breaking it down much more quickly?
Is this going to drive up the price of milk? Corn went up when we started making ethanol from it for gasoline.
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I've said before that we need a short term plastic that completely dissolves into harmless organic compounds that can then be forgotten in nature with no ill effect. 13 weeks is just about right!
Probably wants the "this" from the original title putting back on
>vanishes in 13 weeks

Well then it's not plastic is it? Plastic's defining characteristic is that it is not decomposable

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