Aluminium and plastic closures vs cork: the environmental battle

A study was carried out a few years ago by PriceWaterhouseCoopers to look at the environmental impact of different wine closures, considering cork, aluminium and plastic options. What they looked at was the lifecycle of each type of closure to work out the cost to the environment of 1,000 closures, in terms of energy, water consumption, air pollution and solid waste. The cork industry has been saying for a long time that cork is one of the most environmentally friendly products on the planet, as it comes from sustainable indigenous forests, where the trees are not cut down when the cork is harvested, but left to regenerate so that they can be harvested again.

However, even given the fact that cork trees themselves are obviously only of benefit to the environment, processing the cork obviously has an environmental cost, because it requires machinery for some parts of processing (although natural cork production is still largely manual), transportation, disinfecting and so on. Below is a table showing the main statistics to emerge from the scientific study:


Environmental Indicator                                                                                                       Type of Closure

.                                                                                                                  Cork            Aluminium          Plastic

Non-renewable energy consumption                                                     102              442                     497
(MJ/1000 closures)
Water consumption                                                                                    26               13                       41
(m3/1000 closures)
Emission of greenhouse gases                                                               1,534           37,172               14,833
(g CO2 eq./1000 closures, direct 100 years)
Contribution to atmospheric acidification                                             1.3                8.3                     2.1
(g H+ eq./1000 closures)
Formation of photochemical oxidants                                                    3.5               14.0                    5.1
(g ethylene eq./1000 closures, average)
Contribution to the eutrophication of surface water                            0.6                 0.7                    0.9
(g phosfates eq/1000 closures)
Production of solid waste                                                                         3.7                 7.4                     5.8
(kg/1000 closures)

The main conclusions that can be drawn are that:

  • Corks stoppers use less than a quarter of the energy required to make plastic or aluminium closures
  • Aluminium closures produce 25 times more greenhouse gases than cork and twice the solid waste  (plastic around 10 times the gases and 1.5 times the solid waste)
  • Aluminium produces significantly more atmospheric pollutants that contribute to acid rain and photochemical smog
  • Cork requires more water to produce than aluminium closures, but less than plastic

Many consumers are becoming more conscious of the environmental impact that packaging has; so many products from supermarkets have traditionally come with superfluous packaging that is frequently not biodegradable and made from non-renewable and polluting sources, but over recent years, consumers have been demanding change and many more environmentally conscious brands have listened and adjusted their packaging.

It is really time that wine producers and wine consumers consider the impact of the packaging that they use – aluminium screw top closures might be convenient for some and plastic is no doubt a cheap alternative, but convenience and price should only be a part of the equation. Natural wine corks are a beautiful and natural product and it would be a tragedy for it to be overlooked as a closure for wine in the rush to save money and save drinkers the trouble of whipping out a cork screw (and didn’t that used to be part of the fun of opening a bottle of wine anyway?!).