In very much of a coincidence, the day after reading this at The Elegant Sufficiency, the Picardy newsletter passed across my desk. For those who don't know Picardy, it is a winery in the Pemberton district of Western Australia, started by the Pannell family who also started the very well regarded Moss Wood vineyard at Margaret River. Moss Wood in fact is one of the vineyards that were responsible for putting this region on the wine map and Picardy wines are no slouches either, so when they write about a subject in their newsletter it's well worth listening to what they have to say.

What Stephanie was posting about in part was the issue of cork versus screw cap as the method of wine closure and that on this particular occasion was looking for a wine under screw cap as she didn't want to risk cork taint. I knew exactly what she was talking about and my feelings on the subject seem close to hers, I like wines under screw cap, so it was a bit of a shock to read this from such a well regarded winery.

A recent assessment of a very large number of wines in a UK wine show revealed that 2.2% of them are developing SLO (sulphur like odours) under screw caps. By contrast, due to improved cork selection and treatment, the level of TCA (cork taint) in wines under cork is running at about 1%. This percentage appears to be even lower at Picardy with around 0.3% of cork taint in the wines.
Our Chardonnay, Pinot Noir and Shiraz wines are produced using reductive techniques involving long periods on yeast lees, and are prone to reduction (development of SLO) under screw caps. This problem can be avoided by treating the wine with copper-sulphate (copper fining), but this will remove many of the nuances and complexities which we look for in our wines.
We had always envisaged that when we made a Sauvignon Blanc at Picardy, it would be bottled under screw cap. Research by Dr Henty Sweigers et al at The Australian Wine Research Institute gave us cause to reconsider!
Copper fining is a necessary pre-requisite to bottling Sauvignon Blanc under screw cap. Unfortunately, this process also removes many of the compounds which are responsible for Sauvignon Blanc character in the wine.
We proved this to ourselves by experimenting with a number of bottles under screw cap from the 2006 trial batch of Sauvignon Blanc. The loss of varietal character from the wine can only described as devastating compared to the majority of the wine which is under cork.
Picardy Sauvignon Blanc (due in 2008) will certainly be bottled under cork as a result of this experience.

The newsletter went on to say that screw caps had had a positive influence on the quality of corks, forcing cork producers to find answers to the problem, and cork taint levels that were running at 3% had fallen in their experience to less than 1%. It was interesting that Stephanie had written that she was disappointed in the wine she had bought and given that she spent around thirty dollars, would have reasonably expected something decent, perhaps the wine had been copper fined and as a result was lesser for the experience. It looks like I'm in for a rethink on the whole screw cap versus cork debate.

In another coincidental matter, my friends, Prince Wine Store are offering a free tasting of wines from the Iberian Peninsula, with wines from Spain and Portugal. This is what Jancis Robinson has to say about Portuguese wines...

Portuguese table wines are a mystery – to most non-Portuguese anyway. This is a great shame as Portugal has many unique attributes as a wine producer, not least its dazzling range of indigenous grape varieties, many of them, such as Touriga Nacional, Touriga Franca, Trincadeira and Castelão among many reds and Arinto, Bical and Fernão Pires among whites, with their own powerful and attractive identities. This is in stark contrast to Spain which has almost five times as much vineyard as Portugal and yet has drawn on a much narrower range of vine varieties.

I wonder if any of the Portuguese wines will be under screw cap?

When: Saturday, April 21 (12-2pm)
Where: Prince Wine Store, 177 Bank Street, South Melbourne
Cost: FREE

Edited to add: After I posted this I had a chat to one of the guys at Vintage Cellars about this subject and he added that some wines do better than others under screw cap. He particularly mentioned riesling as one wine that did well and chardonnay as one that didn't. Can anyone shed further light as to which wines work well under screw cap and those that don't?

Labels: cork, Portuguese wine, screw cap