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Wednesday 25th May 2016
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Why Does The Head on a Pint Taste So Much Worse?


Why does the head on a pint taste so much worse than the rest of it... whereas it doesn't in pop?
Matt, Clapham


Name: Mike, Maida Vale
Qualification: Chemical engineer dealing with foam (although usually with crude oil)
Answer: Foam on ale is 'stable' foam and lemonade is 'unstable' foam - to do with the speed it disapates. The reason a foam is stable is it has surfactants that like the interface between the foam and the liquid. They congregate between gas and liquid so have a higher concentration on the foam than in the liquid. It is these that taste bad and they only form in this way in stable foam.


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