Amorim get tough on cork taint

Posted by Helen Tate on 30 July 2013

Amorim get tough on cork taint

Amorim who are the world’s largest cork manufacturer, are about to unveil their latest piece of technology designed to detect trichloroanisole (TCA) compounds responsible for “corked” wine.
Amorim have joined forces with a UK firm specialising in gas chromatography analysis, to create an industrial-scale prototype which will allow corks to be tested individually.
At present the gas chromatography system requires 14 minutes to analyse a single cork sample, rendering it impossible for large scale use outside of the laboratory, despite this Amorims 15 machines in use allow 1.5 million of the 3.6 billion corks it produces every year to be checked.
The new prototype will allow one cork to be analysed every 20 seconds enabling Amorim to check up to 1.5 million of the 3.6 billion corks it produces every year.
Early testing has shown that the machine can detect 100% of corks with above 5 nanograms (parts per trillion) of TCA per litre, however this rate decreases to 88% for corks with TCA levels of 5-2ng/litre, which is still within the human threshold level of detection.
Lopes stated that, “We’re working to reach 100% on this range too,” which involves treatment using ROSA, an Amorim-patented steam treatment machine which, the company believe, removes any remaining TCA molecules perceivable to humans.
Lopes explained that: “Today we know TCA is not formed during production; it is a compound already found in the forests.” Discovered due to other closures entering into the mainstream sector. Therefore, Amorim are working to pinpoint which cork forests contain the greatest TCA levels.
Throughout cork production, a number of protocols are enforced in order to reduce TCA risk. Just after harvest, in order to prevent the onset of mould, which is a precursor of TCA, the bark is left to dry on metal rather than wooden pallets. Next, a boiling system cleans and flattens out the bark using frequently filtered water at a consistent temperature, which flows freely surrounding the cork, this aeration speeds up drying dramatically.
The lower part of the cork bark is removed due to its proximity to the forest floor, which makes it more susceptible to TCA contamination. Peroxide is used to clean the cork, in preference to chloride, as chlorine is a major component of the TCA compound.
Human sensory analysis is used as well as mechanical decontamination processes, including a vaporisation process before the corks are punched, which donates a 40% reduction in TCA, and the INOS II water bath applied to discs for twin top or sparkling wine corks, which contributes a 70% reduction.
Following the gas chromatography analysis, two types of Amorim’s patented ROSA steam treatment are utilised: namely a more vigorous version for granulated corks and a gentler, longer process for whole-punched corks, which results in a TCA decrease of up to 90% and 80% respectively, in addition to removing other volatile compounds.
These processes combine to result in Amorim decreasing average TCA levels from 2.68ng/l to 0.54ng/l between 2003 and 2012 for its whole-punched cork stoppers.
Despite these developments, cellar contamination remains an issue, however, data implies that wine bottled under cork is less vulnerable to this risk due to the material’s relative impermeability compared with synthetic cork, plastic-lined screw cap and the crown caps used for Champagne prior to disgorgement.
Antonio Amorim, chairman of Amorim, stated that: “the biggest challenge is to give consistency to cork.” However, he asserted that: “People have to accept there is the same problem with other closures.”
He also advised that manufacturers need to offer a range of closures, as:  “Different wines will take different corks – and probably even different closures.”


Source: www.thedrinksbusiness.com

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