Strawberry and Buttercup may provide us with litres of fresh, nutritious milk, but you don't get to drink it until it's been pasteurised and sent to the market in clean containers. However, even with the best of care, milk can taste off before its use by date has expired.

The occasional tainting and off smell is due to tiny organisms called psychrotrophs.

"These sorts of organisms enter the milk after the milk has been pasteurised and enter from the factory environment."

At the right temperature, the psychrotrophs will thrive, and although they won't cause you any harm, they are certainly unpleasant. And until now, there hasn't been a reliable test to determine if they were present. But now scientists from Food Science Australia have developed a world first - a super sensitive test, called Psychro-Fast, which can detect the organisms.

Psychro-Fast is added to a milk sample from the large vats, at the factory, then incubated at 30 degrees overnight. If psychrotrophs are present, their numbers rapidly climb to millions per milliliter and the indicator turns the milk sample pink.

So if Strawberry's milk turns to strawberry pink, it's thrown away guaranteeing that only psychrotroph free milk gets to the market place and you don't get an unpleasant surprise.

CSIRO Enquiries
Email: Enquiries@csiro.au
Phone: 1300 363 400
Locked Bag 10
Clayton South
VIC 3169