It is not every day that I get to drink both 50-year-old wine and 100-year-old wine. And no, I did not spit: I enjoyed these wines to the full.

“This is an old wine,” Wilhelm Weil says as he pours the glasses without showing us the label, as we follow a tasting through the 2020 vintage at Weingut Robert Weil with something completely different.

The wine is a dark caramel color and looks and smells sweet with a very mature nose showing honey, figs, caramel, and all the signs of intense botrytis. But it tastes almost dry.

It’s a Cabinet (with a C not a K). “Cabinet was the idea of dry wine in the early part of the twentieth century,”  Wilhelm says.  “I don’t know exactly, but there was a different view of dry wine then, and I would expect it had about 20g residual sugar.”

I’m sure that it must predate the second world war, and I’m thinking it might be 1937 or 1934 when Wilhelm shows us the label: it is 1921, perhaps the greatest year of the twentieth century. We celebrated its one hundred anniversary.

Botrytized notes dominate the palate, but without the kick of sweetness you usually get with a botrytized wine. It’s quite buttery, with the dryness letting some herbal impressions come through,  still lively, and wonderfully elegant.

We then went to dinner with Peter Winter of Siftung Georg Müller. After several current wines, we finished up with the 1971 Hattenheimer Wisselbrunnen Auslese.

It is now a medium caramel color. The restrained nose shows botrytis, following to a palate which is honeyed, figgy, buttery, with notes of caramel. The palate is now just off-dry. The wine has moved to an almost savory overall impression on the palate with age, but acidity still keeps it lively.

Peter says that not every bottle is this good, and that accords with my own experience of a 1971 Schloss Vollrads Spätlese, where I have been drinking one bottle from a case in my cellar every few years. (I have one bottle left.) There have been some real ups and downs, but the last bottle, a few years ago, was almost dry and quite savory, and contrary to all expectations, the best yet.

Based on the extensive statistical sample of these three instances, my rule of three is that an off-dry wine will taste bone dry after 50 years, a sweet wine at Spätlese level will taste almost dry, and an Auslese will taste off-dry.

This reinforces my view that if you find German wines to be a little sweet at any level (from nominally dry Grosses Gewächs to rather sweet Auslese) just wait a few years for the sweetness to lessen. Of course, it may not be practical to wait 50 or 100 years, but even after 10 years there is some reduction in sweetness, and after 20 years it can be quite substantial.

A certain absence of information on the subject leaves room for much misunderstanding. When I was discussing Grosses Gewächs last week with a sommelier in the Mosel, he advocated a younger vintage on the grounds that “it has more acidity, older vintages lose acidity”. Oh dear. In fact, hydrogen ions (i.e. acidity) have nowhere to go, and acidity does not change much as wine ages. Sweetness on the other hand really declines. The basis for the reduction in sweetness is quite unknown, but the best suggestion I have seen is that sugars might polymerize like tannins and lose sweetness as a result. I wish someone would investigate this scientifically.