Pulp fiction? What Oatly, Califia and Alpro do with their oat milk by-product

We are living in the age of oat milk. Recent research found that in the UK, oat milk has overtaken almond milk as the No. 1 plant-based alternative to dairy, with £146m spent on the drink in 2020, doubling from £74m in 2019. It is likely that the number for 2021 will be even higher. Overall, 32% of Brits were drinking plant-based milks instead of dairy in 2021, up from 25% in 2020.

With oat milk established as the leader in the market, what is the most sustainable oat milk drink? While factors like packaging, working standards, energy sources for factories and sustainable investments can all be considered, I am interested in how the companies deal with the food waste – namely, the oat pulp – left over from oat milk production.

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Food waste in oat milk production

If you have ever made oat milk yourself, you will be aware of the oat pulp that you are left with after sieving out the lovely creamy liquid. It is still edible and full of nutrients, and throwing it away would be wasteful. So what happens to those leftovers when oat milk is made on an industrial scale?

Oatly told me that they produced 41,000 tonnes of oat pulp in 2020 alone. With 50% of people making the switch to oat milk because of environmental reasons, it is important to dig into the implications of the waste by-product created by big oat milk companies.

I asked Oatly, Califia and Alpro what they did with the oat pulp. This is what they said.


For Oatly, it depends on where oat milk is being produced. At their facility in Landskrona, Sweden, they send the residues to a local pig farm to be used as feed. With almost half of all grains and soybeans in the world grown specifically for the purpose of feeding to livestock, using food waste to provide those nutrients instead is a great advantage. However, Oatly has had kickback from customers who do not want their money to go towards rearing animals for meat consumption.

In their North American production sites in Millville and Ogden, Oatly sends the oat residues to local food waste recycling companies to be turned into biogas and bio-based fertilizer. In Vlissingen, the Netherlands, the residues are turned into biogas as well.

The sustainability of biogas is complicated; while better than natural gas, oil or coal, biogas can be harmful to land and climate when done wrong. It can also incentivise waste production, rather than reducing waste in the first place.

Oatly received the equivalent of $380,000 in grants to develop food prototypes from the pulp instead, but it appears that this has not yet been successful.


To deal with their oat residues, Califia outsources a huge waste management company called PreZero which is part of the Schwartz Group. The Schwartz Group is the fourth biggest retailer in the world by revenue, reporting a turnover of €125.3 billion in 2020/2021 fiscal year. It owns Lidl and Kaufland, a popular supermarket in Germany and other European countries. It makes sense that a giant food retailer would own a large waste management company, as supermarkets create so much waste throughout their supply chains.

Califia says that through PreZero, the organic food waste left over after production is given to local farmers and is run into their farm slurry. Slurry is a mixture of water and solids, usually manure, that is used as an efficient fertilizer for crops. Unfortunately, there are some severe risks in producing slurry, including exposure to dangerous gases like methane, ammonia and hydrogen sulphide. Slurry is also a destructive pollutant that can damage waterways or cause leaching. In the UK, it is illegal to store slurry within 10 metres of inland or coastal waters or spread it within 50 metres of any water source.


Alpro were the least forthcoming. They said their residue went to livestock feed, but were unable to disclose who and where their partners were, and what kind of livestock.

Pulp fiction?

When questioned, each company was reluctant to give the full picture. Oatly said that “biogas production does not generate greenhouse gas emissions”. Biogas does indeed produce greenhouse gases, but it is considered carbon neutral because the plants absorb carbon dioxide while they are growing. Nevertheless, crops grown for energy displace land that could be used for nature, and in terms of oat waste, the emissions from biogas production would not exist if oat milk was not produced on an industrial scale.

The first response Califia gave was “We don’t have oat byproduct, as we use the whole oat in our process.” When I reminded them of the statement on their website that contradicts this answer, they were more forthcoming with a response. On their website, they categorise the oat residue as “small amount of organic food waste left over after production”. But if it is the same amount as Oatly, 41,000 tonnes a year is not “a small amount”. They declined to share how many tonnes they produced.

What is the best oat milk for food waste?

The best way to use oat pulp is to turn it into food that humans can eat and therefore produce no waste at all. Whichever oat milk company that does this first will be the most sustainable in terms of food waste. It isn’t hard; I have made my leftover oat pulp into bread, muffins and pancakes.

Making your own oat milk is still the most sustainable option. You control how much you make, there is much less packaging and energy used to make the milk, and you decide what you do with the oat pulp afterwards. But not everyone has the time, energy or resources for this.

An up-and-coming oat milk producer with ambitions to create edible food from oat pulp is Minor Figures. They say they currently donate spent oats to livestock feed, but that they want to “up-cycle the used grain into a protein source for humans, which would remove any and all ties to animal product industries altogether”. Minor Figures also has refill stations around the country, reducing the amount of packaging consumers have to use.

If you care about transparency, Oatly and Califia were more willing to share information than Alpro, although painted a rosy picture of their business practices. As a consumer, you can continue to pressure oat milk companies to be transparent through social media or online forms.

I still avoid Oatly because of their relationship with Blackstone, an investment company with activities linked to deforestation. Oatly’s CEO said that Blackstone plays “an essential role in order to create real sustainable change”, which is disingenuous considering that Blackstone invests in two Brazilian firms that have deforested the Amazon to build a controversial highway in order to export soybeans. In addition, its CEO donated to Trump’s administration, which infamously pulled the USA out of the global climate Paris Agreement.

Please let me know if you find out more about how companies manage their oat pulp leftovers, or if you use your own oat residues in any other creative ways!

Main image adapted from Nour Tohme

Published by foodwastestories

The first food waste magazine.

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