Excessive Copper in Screw Capped Wine Bottles

Last year I wrote an article for Harpers' Closures supplement in which I discussed why copper sulphates were being routinely used throughout Australasia to make wines safe under screw caps, and the negative effect this had on an individual wine's terroir and typicity.

So, it comes as no surprise that a German company has rejected a 4,000 cases shipment of New Zealand Pinot Noir because, at 2.6ppm, it contained excessive levels of copper sulphate. The EU's legal limit is I ppm, the same as the joint Australian and New Zealand standard for wine, and higher than the US's 0.5ppm limit.

New Zealand does not currently test for residual copper sulphate levels in wine for either export or local consumption, so it is impossible to know the extant of excess levels across the country's wine base.

Ten years ago, the cork industry had all the hallmarks of the tobacco lobby: denial and argument based on biased, industry-generated scientific trials.

Over time the cork people came to their senses, cleaned up their business and greatly improved the quality of their product.

The screw cap lobby, it seems, has a lot to learn from the reformed cork industry.

Paul White, Wine writer, Wellington, New Zealand