There was a very good article about natural cork in our Independent newspaper last week (you can find the reference on jancisrobinson.com) which, for once, was admirably objective. (So much of the fire and brimstone on this topic is supplied by those who have made up their minds either one way or another.) The pro-cork gist was eloquently and dispassionately put - all that stuff about natural eco-systems in S Portugal being destroyed. Now of course that is not sufficient argument for us all to continue with natural cork if it results in a significant proportion of tainted bottles but it is one factor to bear in mind (even though it is my belief that because so much more wine is sold in bottle rather than bulk nowadays, global demand for natural corks is still rising quite significantly). I would advocate hanging on to natural cork for some wines only if it were proved that this was a sensible thing for wine quality. Unfortunately, the only serious scientific study of different closures so far undertaken over any length of time has been for quite simple white wines (AWRI who when I last asked weren't planning a similar one for oaked whites or reds). My comparative tastings suggest that screwcap/Stelvin is excellent for aromatic unoaked whites but the jury is out on oaked wines. These are much less transparent anyway and tend to exhibit TCA taint less, but I wouldn't mind betting there is some qualitative benefit, as yet under-explained, of aging serious, oaked wines under natural cork over the long term. In the mean time, I'm naturally prejudiced in favour of producers who risk consumer disapproval by putting any sort of wine under screwcap.