This has an impact on the amount of carbon dioxide emitted as a result of bottle manufacture & transport (empty & full) to market.
Bottle weight & carbon dioxide emissions are directly linked to origin. For example carbon emissions for a 1000 case container of wine from Bordeaux, France, are 71% less than those from Nelson, New Zealand (source JF Hilebrand Carbon Calculator).
The average empty 75cl wine bottle weight imported into the UK is 500 grams (according to WRAP, Waste & Action Resources Programme). Reducing the bottle weight to the lightest available on the market of 300 grams would result in a 30% reduction in carbon emissions from Australia (WRAP). Regrettably heavy bottles have become erroneously associated with higher quality wines; particularly those from aspirational new world producers wishing to make an imprint on Wine Shows & Journal Tastings.
A recent Berrys’ supplier survey (Sept 2008) revealed that the average bottle weight (75cl) to be 574 grams, with the heaviest being 633 grams & lightest 555 grams. Berrys’ New World suppliers’ bottles average out at 563 grams, only 2% lighter than the French equivalent (excluding the heavyweight Champagne bottles at 900 grams); a function of the market. While 14% of respondents are looking to switch to lighter bottles, regrettably there are still instances where empty bottles are shipped from France to the Southern Hemisphere only to be filled & returned to Europe for sale.
Research by Yalumba, Australia’s Oldest Family Winery, calculated that a wine’s closure is responsible for less than 1% of a wine bottle’s carbon footprint, with overall packaging at 5%.
A recent 2008 Life Cycle Analysis by Price Waterhouse Coopers of cork, screwcap & synthetic closures, sponsored by cork supplier Amorim, concluded that cork had the least overall impact on the environment; the indicators measured being energy & water consumption, green house emissions, atmospheric acidification, photochemicals, eutrophication of surface water & waste. The aluminium screwcap was shown to be the least thirsty during its manufacture of the three.
In today’s high-tech world, sealing a finely-honed wine with a piece of wood might seem incongruous yet cork remains the closure of choice for c. 80% of the market. Its hegemony has remained unchallenged for nearly two hundred years…until cracks started to appear in the mid-1990s, causing taint & premature oxidation, estimated at between 5 – 10%, directly attributable to sub-standard cork; the result of years of underinvestment. As a result swathes of New World producers, fed up with apparently being offered only those corks previously rejected by their Old World counterparts, gave up the cork in favour of the aluminium screwcap; something incidentally they’d pioneered back in the 1970s.
Bounced into action the cork industry seems to have cleaned up its act & its corks. A new generation of ‘technical’ & agglomerate corks have been introduced, promising a performance closer to that of a screwcap.
‘Synthetic’, plastic corks have provided alternative form of relief from cork taint for some (mostly among Old World producers), as well as saving them the cost of retooling for screwcap, but with it has come creeping concerns over oxidation - significantly more than with cork. They are rarely adopted by fine wine producers.