Long-term closure performance benchmarking trial
The client
Diam Bouchage is the leading global supplier of technical cork closures for the wine and
spirits sector. The company sells over 2 billion closures globally every year and supplies
more than 80 countries worldwide.
The company prides itself on designing innovative products to provide wines and spirits
producers with closures that optimise the aromatic profiles during ageing.
The challenge
As a natural product, cork closures can be inherently variable in their ability to protect wine
in the bottle. Diam’s patented process uses supercritical CO 2 to extract impurities from the
cork, including TCA (responsible for cork taint).
Diam approached Affinity Labs to gather objective data on its closures’ ability to protect and
harness the development of high price-point Australian white (Semillon) and red (Cabernet
Sauvignon) table wines.
The solution
Chemical, physical and sensory analysis were carried out on the series of wines at regular
intervals over a 10-year period, to evaluate the impact of two of Diam’s best-selling
commercial closures, alongside established natural cork and screw-cap closures.
Results showed that wines under the Diam closures compared favourably with the
established reference closures, in terms of sulfur dioxide (SO 2 ) retention and colour
development. The relatively low oxygen transmission rate (OTR) of these closures resulted
in the display of more prominent fresh fruit and floral characteristics during extended ageing,
when compared with wines sealed with the screw-cap closure.
The outcome
The results provide winemakers with independent unbiased evidence of the effectiveness of
the Diam closures, in comparison with established natural cork and screw-cap closures,
allowing them to make informed decisions for their wine products.
‘The study provided valuable information for Diam, proving that the consistency and the
controlled oxygen permeability of our closures can help to extend the cellaring period and
provide a long shelf-life for wines.’
Christophe Loisel, R&D Director, DIAM BOUCHAGE
