There is probably no chance of China's supermarkets doing away with free plastic shopping bags - like some of ours here tried to do, before changing their minds - because, there, you can buy beer in plastic bags.
Soft drink, milk and water producers swapped from glass to plastic bottles years ago: Coca-Cola introduced plastic in 1978 (although the first plastic bottles were made in 1947).
The wine industry here introduced plastic bags in cardboard cartons in the 1980s for still wine made for early drinking.
But beer in plastic here is limited mainly to the refillable 1.25-litre to 2-litre PET (polyethylene terephthalate) from pubs and some smaller brewers. They replaced the refillable glass half-gallon flagon ("half-G" or "Peter" as it used to be known) from the 1960s.
Beer in plastic is more widespread overseas. The PET was introduced in the United States in 1998, mainly for sales at sports stadiums. PET sales account for about 10% of US beer sales.
Sales of beer in plastic in Europe now account for more than 10%; in Korea, more than 15%. In Latvia about three-quarters of all packaged beer is sold in mostly 1-litre plastic bottles. Heineken this year introduced two of its brands in 1.5-litre plastic bottles in the Czech Republic.
Local breweries have been slow to move into plastic: Lion and DB Breweries say plastic might be feasible as the technology improves. But perhaps the main obstacle is their fear drinkers will see a brew in plastic as of lower quality.
DB Breweries has been producing 400ml PET bottles of Tui, DB Draught and Export Gold since 1999 for sports and music events where glass or cans are banned. The third-largest brewer in the country, Christchurch-based Harrington's recently started selling 2-litre PETs in a supermarket, and intends introducing a 1.5 litre for wider distribution.
Our breweries' reluctance to move to plastic is mainly because plastic breathes, letting in oxygen, which is the enemy of beer (and wine) but not of soft drinks, water or milk.
The plastic-based PET bottle (introduced in the 1970s) is the same as that used for non-alcoholic beverages, but with additional layers of resin coatings to inhibit the entry of oxygen and also the egress of carbon dioxide.
Even then its shelf life is limited compared with glass bottles or aluminium cans (up to 12 months). Soft drinks will last three or four months in plastic, but opinion varies on how long beer lasts. Dunedin-based Emerson's, which fills 1.25-litre or 2-litre PETs, recommends consumption within 10 days. Harrington's has a shelf-life of a month; DB claims four months.
Some overseas breweries claim a shelf-life of up to 15 months from advances on the PET.
Plastic bottles can be recycled but resin-based coatings make them less recyclable, thus less socially acceptable.
