Cork is the most sustainable form of closure, study finds

A year-long life cycle analysis (LCA) of the environmental impact of cork, plastic and aluminium screwcap stoppers has found what is already widely accepted: that cork is the most environmentally-friendly stopper.

The was study undertaken by analysts PricewaterhouseCoopers, commissioned by Amorim, the world’s largest cork manufacturer.

The report found plastic stoppers, including the plastic capsule that goes over the top of the bottle, are nine times more damaging to the environment – and aluminium screwcaps are twenty-two times – than cork stoppers, including corks with a plastic capsule.

The LCA included an evaluation of a plastic capsule designed for both cork and plastic stoppers to compare ‘like with like’ against screwcaps, which do not need a plastic capsule.

The first independent survey comparing all three main types of wine bottle stopper, the study was conducted in accordance with

ISO (International Standards Organisation) protocols which require peer

review, and involved representatives from manufacturers of the other types of closures as well as a life cycle analysis expert.

It calculated various environmental impacts: non-renewable energy consumption, water consumption, greenhouse gas emissions, atmospheric acidification, formation of photochemical oxidants which cause ozone layer depletion, the production of solid waste, and the eutrophication (loss of animal life) of surface water.

Of the seven environmental impacts studied, cork performed best on six of them. But performance was only second-best on water consumption.

Written by Sally Easton