Considering the savings it generates, it is surprising that partial homogenization is not more widely used. Because you only put about one fifth of the product flow through the homogenizer – with the rest bypassing it – you can invest in a smaller and less expensive machine. And the savings don’t end there: partial homogenization also allows dairy producers to drastically reduce their operating costs.
“Partial homogenization is not something that is often talked about or widely used, but it does offer huge savings,” says Nicole Uvenbeck, Line Product Manager at Tetra Pak.
In full-stream homogenization – which is the common approach to homogenizing milk – the product is standardized before homogenization and the entire flow passes through the homogenizer.
In partial homogenization, a maximum cream fat content of 18% is recommended. This results in a flow through the homogenizer of about one fifth of the full-stream flow. The skim milk simply bypasses the homogenizer. The skim milk flow and the 18% fat flow are then mixed together to the desired final fat content, and the same end product is achieved as with full-stream homogenization.
As an example, instead of 20,000 litres of milk going through the homogenizer, with partial homogenization only about 4,000 litres is homogenized. What does this mean in financial terms? “You can buy a much smaller model of homogenizer, so investment costs are lower – in this case around 55% lower,” says Uvenbeck.
In terms of running costs, the reduced demand for electricity, cleaning in place and water means that partial homogenization can bring down these costs by a massive 70%, compared with full-stream homogenization.
“Some suppliers might not be comfortable with only homogenizing the cream part, or wouldn’t even dare to think that it would work,” says Uvenbeck. “But we have a lot of experience with partial homogenization and know that it does work. There are lots of dairies out there that could really save a lot of money by selecting partial homogenization.”
How they compare: full-stream homogenization versus partial homogenization
|Tetra Pak Homogenizer 300 (full-stream homogenization)||Tetra Pak Homogenizer 200 (partial homogenization)|
|Cleaning in place||33kW||6kW|
|Flow through homogenizer||20,000 litres/hour||3,890 litres/hour|
Specification: Tetra Pak Homogenizer 300 and Tetra Pak Homogenizer 200.
- Capacity: 20,000 l/h for full-stream homogenization and 4,000 l/hr for partial
- End product: milk with 3.5% fat content
- Pressure related to chilled milk, one-week shelf life.
- Running time: 12 h/day
- 300 days/year
- 2h CIP/day
Partial homogenization is mainly applied to pasteurized market milk.
55% in investment cost
73% in annual running costs.