Dairy Science Information

Ultra Heat Treatment basics

Milk Processing Record Format
Milk Filler HACCP Sample
UHT Milk Filler Process Flow sample

UHT is a process where the milk, juice, beer, wine, beverage etc is heated to approx 145 degrees C and held there for some two seconds.

The UHT heat treatment time and temperature combination should be established based upon the product to be treated and it's viscosity etc

UHT product after heat treatment may be sent to a Sterile tank to give a buffer prior to filling

Filling is usually done in a sterile atmosphere where the UHT packing machine flushes the package with Nitrogen and also keeps the area withing the filling heads flooded with Nitrogen to eliminate any air contamination as bacterea, moulds etc require air to grow

The shelf life of a UHT product can be up to 1 year at ambient temperatures

UHT heat treatment can affect the flavour of the product and time and temperature combinations should be established to minimize this effect

The equipment required for uht is straightforward and the first part is a UHT processing line (Heat treatment to a high temperature and also holding section)

Generally UHT plants are tube in tube, plate heat exchanger, shell and tube, scraped surface or direct steam injection and all systems will have a simple holding section matched to the product and required holding time.

The type of systems vary in the degree of automation and also damage to the product so careful selection of the type of system should be made based upon accepted industry standards for the product to be heat treated

The immediate advantages of the aseptic process settled its success wherever it has been introduced. This technique allows products, formerly considered perishable, to be stored and distributed without refrigeration for prolonged periods of time (from 6 to 24 months depending on the product).

In addition, the aseptic package ensures a contamination free product with virtually no loss of quality, taste or nutritional values. The aseptic process can be utilized to package a wide range of products, such as milk and dairy, fruit juices, flat drinks, wine, mineral water tomato sauce and others.


The aseptic packaging machine forms, fills and seals packages in one continuous operation in a sterile environment.

The first "step" of the aseptic process is the sterilization of the product by heating and then cooling. The treatment temperature and holding time is varied according to the type and viscosity of product. The package seal is based on an internal polymer and internal polymer melting and eliminating exposed edges from the inside of the package.

For sterilization, hydrogen peroxide (H²O²) may be utilized depending on country legislation and the sterilizing agent at the end of the sterilization residues is less than 0,5 parts per million

Holding time should be be validated / checked annually (www.easytest.biz) and also heat exchangers should be checked for cracks on an annual basis.
For more information or to discuss your requirements please contact us.

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