Food technologist - Vanessa Ralph

It's possible to make butter by hand, but it takes a long time and a lot of hard work.

Butter is believed to have first been made by the Celts in fifth century Ireland. The first step towards mechanising butter production was the development of the continuous butter making machine in the early 19th century, but this was not used in commercial production until after World War II.

Today most butter is made in a factory, where there are six stages in its production: separating the cream from the milk; heat-treating the cream to destroy micro-organisms and remove off-flavours; cooling the cream and allowing it to crystallise; churning the cream until the buttermilk separates from the fat; adding the salt (for salted butter); and finally, packing the butter into tubs.

I help make butter in the Bonlac Foods factory at Cobden in the heart of one of Victoria's main dairying regions. My job is to pasteurise and heat-treat the cream. It's an important job because it helps to ensure the quality and microbiological safety of the butter you buy. We also sell butter and other dairy products to many other countries including the former Soviet Union, the Middle East, Asia and New Zealand.

Growing up on a dairy farm meant that I had an early interest in the dairy industry. Then at high school I read about the associate diploma of applied science in dairy technology at TAFE and decided that was what I wanted to do. During the course I studied a range of science and applied science subjects such as frozen milk products. After completing my studies, I joined Bonlac Foods, where I have worked in several different areas including powdered milk production, buttermaking and packaging.

There is a lot more science in food than most people realise.

"Science Futures" was produced by Wisenet with the aid of a grant from the Department of Industry, Science and Tourism Science and Technology Awareness Program.