Ever passed a chip shop and found yourself drawn in by the delicious smells?
Now experts think they have discovered what is behind the aroma - and it is a mixture of butterscotch, onion and ironing boards.
Food scientists at Leeds University unravelled the smell of chips in the laboratory as well as using human noses.
They broke down the smell into components using a process known as gas chromatography mass spectrometry.
An analyst sniffed the smells that could be detected by the human nose and recorded their type and strength.
The results showed chip aroma is made up of butterscotch, cocoa, onion, flowers, cheese and ironing boards.
The research, commissioned by the Potato Council for National Chip Week, was led by Dr Graham Clayton.
He said: "Whether oven-cooked or fried, the humble chip doesn't smell of just chips - the aroma is much more complex and probably explains why chips are everyone's favourite.
"One might not expect to find butterscotch or cocoa aromas in chips, but it has to be remembered that these are one part of the overall aroma.
"Perhaps these findings will see chips treated like wine in the future - with chip fans turning into buffs as they impress their friends with eloquent descriptions of their favourite fries."
The kind of potatoes, oil, cooking method and temperature all affected the aroma.
Dr Clayton said: "Lightly cooked or undercooked chips were found to contain three simple aromas including bitter cocoa.
"A little extra cooking was shown to produce a more complex aroma profile, with up to nine different aromatic notes."