per cent nitrogen and 25 per cent CO2. This premixed gas which only works well with creamy beers is often referred to as Guinness Gas, Beer Gas, or Aligal. Using "Beer Gas" with other beer styles can cause the last 5 per cent to 10 per cent of the beer in each keg to taste very flat and lifeless. Keykeg Since the 2000s, a number of brewers and outlets have been introducing a variation on keg dispense. Keykegs deliver the product under gas pressure, but it is internally held in plastic bag, rather like a wine box, so that the gas does not affect the beer. Keykeg beer can also be naturally carbonated, and lightly filtered, removing some of the objections to the older keg format. Nonetheless, it retains much of the advantage in terms of shelf life of the older keg format. Almost any kind of beer can be delivered in this format, although it tends to be mainly associated with imported, stronger, and speciality beers. The keykeg format is suitable for transporting beer internationally, unlike traditional cask ales, allowing pubs and other outlets to offer a cosmopolitan range. On the other hand, this is a plastic single-use keg. What is, environmentally a major disadvantage. Sparkler A sparkler is a device that can be attached to the nozzle of a beer engine. Designed rather like a shower-head, beer dispensed through a sparkler becomes aerated and frothy which results in a noticeable head. Some CO2 is carried into the head, resulting in a softer, sweeter flavour due to the loss of normal CO2 acidity. There is some dispute about the benefits of a sparkler. There is an argument that the sparkler can reduce the flavour and aroma, especially of the hops, in some beers. The counter argument is that the sparkler takes away harshness. A pub may favour sparklers because the larger head they produce means it does not need to supply as much beer. Breweries may state whether or not a sparkler is preferred when serving their beers. Generally, breweries in northern England serve their beers with a sparkler attached and breweries in the south without. Bottled beer Whilst draught beer takes up the majority of the market, bottled beer has a firm place and is a growing sector. Some brands are sold almost entirely in the bottled format, such as Newcastle Brown Ale and Worthington White Shield. CAMRA