But how well do we actually know this magic bean? Not as well as we could, the owner of Ankina Coffee, Frank Standford, says.

''There is still 20 per cent of the roasted bean that we are unsure of its actual make-up,'' he said. These unidentified compounds remained a mystery for the coffee industry, but more was being learned about it every day.

Canberra's connoisseurs took a look at a few of the changes that science has brought to coffee production, in a session held last night as part of the Australian Science Festival.

Coffee trading expert Nick Chronis said, ''There's probably six key stages in coffee production and science is through all facets of it.

''The first process is planting the coffee tree where you plant it, altitude plays a big part in this.''

Mr Chronis said some types of coffee trees were best suited to low altitude, others to high and selecting the right plant type could influence the flavour of the final product. Moving from hand-picking to mechanical harvesting had also had a big impact and not always a good one.

''The best beans are hand-picked,'' Mr Chronis said.

''The trade-off of totally automating the process is a trade-off in quality.''

But in other areas, like the roasting of coffee beans, new technologies had improved outcomes in the coffee cup.

A new generation of coffee roasting machines could check the grade of roast they were making using light. ''The key innovation this machine has brought to roasting is the computer software that comes with it so you can actually program the roast blend . You can program it to roast at X degrees for X minutes to achieve X flavour profile.''

The science of coffee will be discussed again tomorrow at 6pm in Old Parliament House. Bookings: 62734366.