Milk permeate is a by-product of the dairy production process, formed after ultrafiltration of milk to extract protein and fat used to produce cheese. Permeate has a watery consistency, and is green in colour due to the presence of B vitamins. It consists of lactose, water, vitamins and minerals.
Permeate may be added to fresh milk as part of a process called standardisation, to keep consistent levels of fat and protein in the product which may have seasonal variations. In addition, using permeate as an additive can save dairy processors the cost of disposing of the product.
Controversy in Australia
The re-addition of permeate to milk has caused some controversy. In 2008, dairy farmers in Australia accused food producers of "watering down" milk with permeate to save costs by reducing the volume of milk required from farmers. The processors acknowledged that permeate was added to milk for retail sale, but that this was done to standardise levels of fat and protein as required by food standards regulations. However food standards just require a minimum content of fat and protein for regular milk, and a maximum fat content but same minimum protein for skim milk.
Although there are no known health risks associated with consumption of permeate, further consumer concerns in 2012 over its addition to milk resulted in several milk brands and dairy processors in Australia declaring their products as "permeate-free".
- Beck, Maris; Hawthorne, Mark (17 April 2012). "Cheese waste in up to 16% of milk". The Sydney Morning Herald. Retrieved 18 July 2012.
- Frith, Maxine (13 May 2008). "Creamed off by milk companies". The Sydney Morning Herald. Retrieved 18 July 2012.
- Locke, Sarina (25 June 2012). "Dairy processors say no to permeate". ABC Rural. Retrieved 18 July 2012.