The test beams a ray of light thinner than a human hair through a transparent chip on which sits some of the precious liquid.
Researchers at the University of St Andrews found that firing light from one optical fibre and collecting it with another allowed them to analyse light scattered from the whisky.
It allows them to work out precisely how much alcohol is in a sample - fake whisky often has less than the required 40 per cent.
But the scientists can also work out colour and texture - and claim they can identify the brand and age of the malt under test, and even which cask a sample came from.
The research, which has been patented and is being presented to industry, was carried out by physicists Praveen Ashok, Kishan Dholakia and Bavishna Praveen.
Mrs Praveen said: 'Counterfeiting is rife in the drinks industry, which is constantly searching for new, powerful and inexpensive methods for liquor analysis.'
'Using the power of light, we have adapted our technology to address a problem related to an industry which is a crucial part of Scottish culture and economy.'
The rapid, easy test could make it far easier to test for counterfeit whiskies both at home and abroad.
Researchers said the method exploits both the fluorescence of whisky and the scattering of light and shift in energy when it interacts with molecules, known as its Raman signature.
Mr Ashok said: 'Whisky turns out to be very interesting. We can not only gather information about the alcohol content but also (about) the colour and texture.'
'These are dictated by the manufacturing process which of course influences greatly the type of whisky people enjoy.'
The group originally used the chip involved in the research to detect 'bioanalytes; in other studies.
Professor Dholakia added: 'It is amazing to think that the technology we are developing for biomedical analysis can also be used to help us enjoy a wee dram.'
The study is being published by the journal Optics Express.