A little background may be in order. A beer widget is the plastic device added to the can that contains pressurized nitrogen gas; when the can is opened, the nitrogen escapes and dissolves into the beer and produces a finer, smaller-bubbled carbonation and head that is thick and creamy. The body of the beer, likewise, takes on a smooth and creamy feel as well.
Guinness developed and popularized the widget; they were researching it as early as 1968 and in the late 80’s, introduced the widget can (which subsequently appeared in the US in 1990).
Since then, the widget can has appeared with other Irish and UK brews, as mentioned above. Which takes us back to the question of why only those beers?
The best partial answer I can find is from this Beer Hunter article that first appeared in 1991. Michael Jackson postulated that it’s a way to capture the British pub experience—the draught-only, cask ale style of beer—in the can for mass market appeal.
This is the only country to have persisted on a large scale with cask-conditioning: the practice of delivering barrels of beer in a not-quite-ready state (with some unfermented sugars, and live yeast) to the pub, so that it can complete its development in the cellar. Because this secondary fermentation can only take place at a natural cellar temperature, and produces only a light, natural carbonation, cask-conditioned beer has none of the aggression of colder, gassier, products. It is soothing and sociable. It fits the mood of the pubs and cannot easily be made available at home….
Brewers would like to retain a "draught" character in bottled or canned beer. In the United States and Japan, the word "draught" on a bottle or can usually means that the beer has been filtered to the point of sterility. This strips out flavour and body, but removes the need for pasteurisation.
The newest trick – being used in the British Isles to make products identified as "draught" in cans – retains pasteurisation but addresses itself to another area of taste: creaminess, softness and gentle, low carbonation In fermentation, beer produces only one gas: carbon dioxide. When it is hand-pulled, the manual pump action introduces air. Within air is nitrogen, and that enhances the texture and head by producing bubbles smaller than those created by carbon dioxide….
Not only does the nitrogen make the beer more creamy, and produce a better head, it also protects against oxidation. The brewer can therefore permit the beer to be less carbonated. The "canned draught" products have levels of carbonation similar to those in cask-conditioned ales, and less than half those in some bottled beers.
This is a compelling case for the British cask/pub experience in a can, so then: why haven’t other canned beers (particularly American) adopted this? Could it simply be because only the British care enough about this experience to emulate it?
Some wild speculations (I may be totally off here):
- Since Guinness owns the patent on the beer widget, it can only be produced in Ireland and the UK. (This doesn’t seem entirely likely.)
- Since the canned craft beer movement in American is only just getting off the ground, it’s simply a matter of time; i.e., American "microcanners" are still getting used to the canning process and experimenting with widgets is inevitable but not there yet.
- Alcohol laws (or FDA or something?) doesn’t allow craft brewers to add widgets/foreign objects to alcohol (cans). Imports exempt?
- Not cost effective for small brewers, who are only just able to start affording canning systems.
Can anyone shed some light on the subject?
Updated: Fixed some geographic problems; see the comments.