Is that coffee or is it wine? Traces of caffeine found in wine.

The proverbial shit hit the fan last week with a letter published in The Sunday Times on 7 August  that traces of caffeine  had been discovered in wine. Yvette Naude of the  Department of Chemistry at the University of Pretoria got more than she bargained for while doing tests on aroma profiles of so called coffee styled Pinotages.

Herewith an extract of her letter:

Some time ago we evaluated aroma compounds in Pinotage to see which combinations of compounds are responsible for the coffee-chocolate note in the so-called mocha-styled Pinotage. While busy analysing a number of mocha/coffee Pinotage wines I idly wondered if the coffee perception was not from wood products alone, but was instead from a little help of the real thing? Lo and behold we detected caffeine in one of the wines …

Upon contacting her for further comment all she would say is that she stands by her findings. The million dollar question is: what wine was these traces of caffeine found in?