"I was working at the lab at Davis and a wealthy American had bought two bottles from the Duke of Northumberland's cellar, so it had good provenance. He had one for a dinner party with his friends and the other we got presented with; I was in charge of the lab and had to do all the analysis on this wine.

Of course, the sophisticated machinery meant we could use 50ml of this wine and the rest we drank. We got all the people who were close to us – top professors like Roger Boulton, and people who would really appreciate the wine. (I still have every one of Roger Boulton's lectures on tape.)

I have tasted many wines when they are 10 years old and they are shot. This was from the 1860s and it was superb. It was honeyed, with nuts; we savored it. After half an hour, it went all brown because there was no sulfur left in it, but it was so memorable.

There are still single bottles around the world and some of them are in the museums, but we got to drink it."

As told to Rebecca Gibb

Fast Facts from Wine-Searcher's search engine:

1862 Constantia

• Country of origin: South Africa
• District of origin: Cape Point, part of the wider Coastal Region of the Western Cape
• Style: Dessert wine
• Grape: Muscat
• History: Famed in Europe in the 18th and 19th centuries as Vin de Constance
• Production: Devastated in the 19th century by outbreaks of phylloxera and powdery mildew.