Ultrafiltration (UF) is transforming modern cheesemaking by concentrating milk’s essential components while removing excess water and smaller molecules. This technique improves efficiency, enhances texture and even extends shelf life. But how does it work? And what impact does it have on the sensory experience of cheese? Let’s explore the science behind UF.
Origins of ultrafiltration
Ultrafiltration was developed as part of membrane separation technology in the 1960s, primarily for industrial and food processing applications. The dairy industry began applying UF to milk processing in the 1970s and 1980s, with researchers in the United States and Europe exploring its potential for improving efficiency and consistency in cheesemaking.
Since then, UF has become a staple in modern dairy production, particularly for soft and high-yield cheeses.
The science of ultrafiltration
Ultrafiltration is a membrane separation process that selectively retains larger molecules, such as proteins and fats, while allowing smaller molecules, like water, lactose, and minerals, to pass through. This process alters the composition of milk before it undergoes cheesemaking.
How it works
- Milk is forced through a semi-permeable membrane under pressure.
- The process divides the milk into two parts:
- Permeate: The fraction that passes through the membrane, mostly water, lactose, and some minerals.
- Retentate: The concentrated fraction, rich in proteins, fats, and essential cheesemaking components.
- The resulting retentate is a milk concentrate with a much higher protein-to-water ratio, making it ideal for efficient cheesemaking.
This technique provides greater control over milk composition, allowing cheesemakers to produce more consistent results in texture and flavour.
Advantages of ultrafiltration in cheesemaking
UF is widely used in industrial cheesemaking due to its ability to improve efficiency and enhance product quality. Let’s explore some of its major benefits:
- Increased Efficiency and Higher Yields: Using UF, cheesemakers can produce more cheese per litre of milk. Since the milk is already concentrated, curd formation is more efficient, reducing whey production and increasing cheese yield.
- Shortened Ageing Period: A major advantage of UF milk is that it reduces the ageing time needed for cheese maturation. Since UF concentrates proteins, it speeds up enzymatic reactions during ageing. This allows cheesemakers to produce aged-style cheeses in less time while maintaining their intended flavour and texture.
- Extended Shelf Life: UF significantly improves the shelf life of cheese by reducing moisture content, which limits bacterial growth. This makes UF cheeses ideal for industrial production and distribution, as they remain fresher for longer periods.
- Consistency in Cheesemaking: By removing variations in milk composition, UF ensures that cheesemakers have precise control over the final product. This is crucial for large-scale production, where uniformity is key to maintaining brand quality.
- Reduced Lactose Content: Since ultrafiltration removes a portion of lactose in the permeate, cheeses made from UF milk naturally contain less lactose. This makes them more suitable for people with mild lactose intolerance.
Impact of ultrafiltration on flavour and texture
While UF improves efficiency and shelf life, it also changes the organoleptic properties of cheese—its flavour, texture and mouthfeel.
1. Flavour modifications
- Milder Taste: The removal of some lactose and minerals slightly reduces the intensity of natural flavours.
- Balanced Saltiness: Since minerals and salts influence taste, cheesemakers may need to adjust brining and seasoning to maintain the desired flavour profile.
- Controlled Fermentation: By using specific starter cultures, cheesemakers can compensate for flavour changes and ensure a well-rounded taste.
2. Texture and mouthfeel
- Creamier, Softer Cheeses: UF increases protein concentration, leading to a richer, smoother texture.
- Uniform Structure: The even distribution of proteins and fats prevents textural inconsistencies.
- Reduced Free Whey: Less water content means firmer cheeses that retain their structure better over time.
A case study: d’Affinois
A famous example of UF cheesemaking is Fromager d’Affinois, a French double-cream cheese known for its ultra-creamy texture and delicate flavour.
Why is d’Affinois so creamy?
Unlike traditional Brie, d’Affinois is made with UF milk, which concentrates the fat and protein. This creates an incredibly smooth, almost spreadable texture that melts effortlessly on the tongue.
Flavour and texture
- Mild, Buttery Taste: The UF process removes some lactose, reducing sweetness and allowing subtle creamy flavours to dominate.
- Thin, Delicate Rind: The cheese retains a soft, edible rind, contributing to its melt-in-the-mouth experience.
Why is d’Affinois’s rind thinner?
D’Affinois has a thinner rind compared to traditional Brie due to the ultrafiltration process used in its production. Here’s why:
- Faster Moisture Loss During Ageing: Ultrafiltration removes excess water, leading to a more even and efficient moisture distribution in the cheese. A shorter ageing time means a thinner, more delicate rind compared to Brie.
- Softer and Creamier Paste Affects Rind Formation: The UF process creates a high-moisture interior, affecting how the surface dries out. Traditional bloomy-rind cheeses like Brie allow for more moisture loss over time, leading to thicker rinds.
- Altered Penicillium candidum Growth: The Penicillium candidum mould, responsible for bloomy white rinds, grows differently on UF cheeses. Since the paste is richer and softer, the mould spreads more evenly without forming a thick rind.
- Shorter Affinage (Ageing) Period: Traditional Brie ages for 4–6 weeks, allowing its rind to develop fully. D’Affinois reaches peak ripeness much faster—often within two weeks—leaving less time for rind thickening.
This results in an ultra-thin rind that melts seamlessly into the cheese, enhancing its luxurious mouthfeel.
Storing ultrafiltration retentate as powder
One of the most practical applications of UF technology is converting retentate into a powdered form for long-term storage and transport.
How retentate is powdered
After ultrafiltration, the retentate can be dried using two main techniques:
- Spray Drying: The liquid retentate is atomised into fine droplets and rapidly dried with hot air.
- Freeze Drying: The retentate is frozen and then subjected to sublimation, removing moisture while preserving protein integrity.
Benefits of retentate powder
- Extended Shelf Life: The low moisture content prevents spoilage and microbial growth.
- Easier Transport: Powdered retentate is lightweight and non-perishable, making it ideal for global distribution.
- Versatility: It can be rehydrated and used for cheesemaking, protein fortification, or dairy-based food products.
Conclusion
Ultrafiltration is an innovative technology that enhances the cheesemaking process by improving efficiency, texture and shelf life while reducing lactose content. However, it also alters the sensory profile of cheese, requiring careful adjustments to maintain traditional characteristics.
The success of cheeses like Fromager d’Affinois demonstrates how UF can create luxurious, high-quality cheeses that balance science with artistry. Additionally, the ability to store UF retentate as powder opens new possibilities for global dairy production and supply chains.
As the dairy industry continues to evolve, ultrafiltration remains a key player in the future of cheesemaking—combining innovation with tradition to produce exceptional cheese experiences.
Cheese lover. Scientist. Created a website and a Youtube channel about cheese science because he could not find answers to his questions online.
