A tap that is opened, clear water flows out… Nothing extraordinary in appearance, except that this water comes from an industrial process of dehydrating milk, and therefore first passed through the body of a cow (AFP / LOU BENOIST)
A tap that is opened, clear water flows out… Nothing extraordinary in appearance, except that this water comes from an industrial process of dehydrating milk, and therefore first passed through the body of a cow.
This “cow water” is commonly used to wash the tanker trucks that have collected the milk. But other uses, in contact with food, are expected to develop, after treatment and depending on local regulations.
On the edge of the coastal city of Saint-Malo (western France), the Malo factory produces premium yogurts of the same name as well as whole milk powder, sold to chocolate and pastry manufacturers.
To obtain this powder, the milk, composed of almost 90% water, is injected into a concentrator, a vertical stainless steel tube around twenty meters high.
On a mini-porthole, drops of steam appear: the water has been separated from the fat, proteins, lactose and mineral salts contained in the milk – all materials recovered in the form of concentrate, which will be further dried and ground into powder.
“With four litres of milk, we will produce one litre of concentrate and three litres of condensate. (…) In our profession, we call that cow water,” explains the site director, Xavier Macé (AFP / Damien MEYER)
“With four litres of milk, we will produce one litre of concentrate and three litres of condensate. (…) In our profession, we call that cow water,” explains the site director, Xavier Macé.
English speakers speak of “cow water”, playing on the word cow and the acronym COW for “condensate of whey”.
France recently amended its regulations to expand the possibilities for reusing this “cow water” as well as wastewater treated in factories’ own treatment plants.
The text took a long time to come out, as the authorities wanted to prevent health risks as much as possible.
Reuse helps reduce pressure on drinking water, which is the subject of conflict between users (farmers, individuals, industrialists, leisure activities, etc.) when it becomes scarce.
The agri-food sector, which feared cuts during the 2022 drought, cannot operate without water, to wash ingredients or production lines. Dairies emphasize their particularity: in the event of a shutdown, milk cannot be collected from farmers and risks being thrown away.
– Beet water too –
In Saint-Malo, the plant uses 20,000 m3 of cow water each year, the equivalent of eight Olympic swimming pools, to wash the exterior of the collection trucks or power the heating system. This represents 10% of its water consumption, for a reduced bill of 40,000 euros per year.
The dairy does not yet exploit all the cow water it recovers and could triple this saving with the relaxation of national regulations. On condition that this water is treated for sensitive uses, such as cleaning the installations between two yogurt flavors.
The site has not yet quantified the necessary investments.
“This cannot be done overnight, we must make the water completely drinkable,” emphasizes Xavier Macé.
A joint report from the United Nations Health Organization (WHO) and the Food and Agriculture Organization (FAO) highlighted in 2023 the “strong potential for exploiting various reusable water sources” (cow water, treated wastewater) in the dairy industry.
Milk is not the only agricultural raw material rich in reusable water: sugar beets contain 75% of it. The French cooperative group Cristal Union recovers the water from the sugar extraction process to irrigate the surrounding fields (AFP / Thierry Zoccolan)
But the large-scale deployment of reuse solutions is slow, regret international institutions, which consider the “sharing of experiences” in this area “urgent” so that even modest dairies can get involved.
World leader in agri-food Nestlé tells AFP that it recycles cow water in several of its milk powder manufacturing sites, “particularly in regions where water resources are limited”. It started with its factory in Lagos de Moreno, Mexico. “Given the success of the operation”, it then deployed the technology in South Africa, Brazil and southern Asia.
Milk is not the only agricultural raw material rich in reusable water: sugar beets contain 75% of it. The French cooperative group Cristal Union recovers water from the sugar extraction process to irrigate the surrounding fields.