Hermit
fuddle
The problem, as far as stouts are concerned, is that the low concentration of dissolved nitrogen means the process works at only a 15th of the rate seen in ales and lagers. But Dr Lee has an answer to that: more cellulose. He and his team spiked their beer with extra fibres from a cut-up coffee filter and watched the bubbles form under a microscope. By crunching the numbers from these observations, they calculate that lining a can of stout with nine square centimetres of fibres should form a head as good as that produced by a widget. If their method works on an industrial scale it will have two benefits. Stout will be cheaper. And those irritating adverts proclaiming that you do not need to know how a widget works in order to enjoy its benefits will disappear for ever.
http://www.economist.com/node/18329424
http://www.economist.com/node/18329424