Today in 1996, US Patent WO 1996012669 A1 was issued, an invention of Alexander Richard Dunn and John Cooke, assigned to Scottish & Newcastle Plc, for their “Method and Apparatus For Enhancing a Beverage Head.” Here’s the Abstract:

A gas jetting apparatus is used to jet a fine jet of gas through an orifice at a nozzle (18) into a beverage, for example beer, to promote formation of a creamy head. This apparatus may be incorporated into a beverage dispenser, for example a beer tap which dispenses draught beer.

And includes the following description:

“Method and Apparatus for Enhancing a Beverage Head”

This invention relates to a method and apparatus for enhancing a beverage head, particularly, but not exclusively, a head on a draught beer dispensed from a tap.

Sparklers are sometimes used to agitate a flow of beer as it is dispensed from a beer tap; this can promote frothing of the beer and contribute to formation of a head on the dispensed beer. It is also known to provide a single use secondary chamber within a sealed, pressurised beer can from which gas and/or beverage is jetted into beer within the can when the can is opened.

According to a first aspect of the present invention there is provided a method of promoting formation of a beverage head, comprising jetting a fine jet of gas derived from a gas source through at least one orifice and into a dispensed beverage.

The method may form or assist in the formation of a head.

The beverage may be dispensed from a tap; it may be a draught beverage.

The gas may be jetted into the beverage once the beverage has been dispensed. Alternatively or additionally, the gas may be jetted into the beverage whilst the beverage is being dispensed, it may be jetted into a stream of beverage.