Ultrafiltered milk is one of the fastest-growing segments in premium dairy. It combines traits that most health-conscious consumers seek out – high protein content, low sugar and fat, and a longer shelf life, all while being natural.
To achieve this, processors put milk through a porous membrane under pressure – a process known as membrane filtration – modifying water, lactose and some natural minerals and concentrate the protein that naturally exists in milk.
Coca-Cola-owned fairlife is the best-selling ultrafiltered milk on the US market. The brand surpassed $1bn in annual sales back in 2022 and has consistently driven non-soda sales for the beverage major in recent years. Its protein shake Core Power is popular with both active and everyday wellness consumers, with Coca-Cola positioning the range as sports performance fuel through a partnership with Olympic swimmer Katie Ledecky.
Ultrafiltered milk is also a key ingredient in healthy snacks such as yogurt pouches. Danone-owned Too Good and Co. recently released a range of kid-friendly flavored yogurt pouches that contain whole filtered milk, 30% less sugar than competitor brands, and no artificial sweeteners or colors.
And in the fresh milk aisle, the benefits of ultrafiltration such as higher protein content and lower lactose can strengthen positioning. Brands such as Organic Valley have leveraged ultrafiltration in a recently-released range of organic shelf-stable milk, which boast 13g of protein and just 6 grams of sugar.
So how is ultrafiltered milk made? “Using ultrafiltration, dairy processors can concentrate milk proteins while allowing water and some lactose and minerals to pass through,” Fiona Liebehenz, vice-president key components, plant solutions and channel management at Tetra Pak.
“This approach enables the production of milk with higher protein content and can, in some cases, reduces lactose, compared with unfractionated milk. These results can’t be achieved through reliance on less precise methods, such as blending and heat treatment, alone.”
Those compositional changes also affect how milk behaves in products, she added. “Concentrating milk through membrane filtration can improve body, texture and stability. This is because protein and total solids are increased through separation rather than additives.”
The process is also used to concentrate protein content in dairy without resorting to additives. “Ultrafiltration and reverse osmosis can raise protein levels by removing water,” said Liebehenz.
“As an example, this enables yoghurt producers to entirely avoid, or reduce the quantity of, milk powder – often used to boost protein and dry matter – without compromising the desired texture, viscosity and stability.”
Membrane filtration also supports the production of reduced-lactose products through separation rather than conversion. “Lactose is reduced by physically removing part of it, rather than converting it by adding lactase enzymes to break lactose down during processing,” she added.
Similarly, in ultrafiltration for fermented dairy, proteins are retained while lactose and minerals pass through the membrane. “This method increases protein density while lowering the lactose content in the remaining product stream,” said Liebehenz. “It reduces the need to rely primarily on enzymatic hydrolysis as the main step for lactose reduction, because the formulation shift is achieved through membrane separation first.”
Membrane filtration has efficiency and sustainability benefits, in terms of reducing the need for chemicals and improving yields.
“Membrane filtration is a way of recovering value that would otherwise be lost as product solids in wastewater streams,” Liebehenz said. “For example, ‘white water’ from production can contain significant amounts of milk solids. Reverse osmosis can be used to recover those solids for reuse while producing clean water suitable for recycling in the plant.”
Membranes are also used to minimise chemical use and waste from cleaning processes. “This lowers the environmental load of wastewater treatment while also reducing operating costs, due to less chemical purchase and less effluent to treat,” she explained.
“For example, Dairygold, one of Ireland’s leading dairy companies, focused its efforts on the cleaning-in-place processes and the reduction of water and chemical consumption. Membrane filtration technology enabled the recovery of up to 90% of the caustic soda used, lowering both chemical consumption and wastewater treatment needs.”
And finally, reverse osmosis enables energy savings in powder production by removing water earlier in the process. “This reduces the load on energy-intensive evaporation and drying stages, significantly improving overall energy efficiency and emissions performance,” Liebehenz concluded.
