What happens when German Riesling gets old

I love sweet German Riesling. If you don't know that, you don't me. I too often get pigeonholed as "Trocken or Bust." I focus on the trocken wines because I would love them one day to be as well known as the sweeter styles and I find the arguments against them specious at best. As I have been pigeonholed as a guy who only likes trocken, Germany, as a wine producing country is pigeonholed as a country that ONLY makes sweet wines. This is beyond wrong. Now, don't get me wrong, I love old sweet German Riesling and I love young sweet German Riesling, Hell, I even love closed sweet German Riesling. When it's young though it is an entirely different animal than when it is old. Many people have varied preferences. Not all sweet German Riesling tastes great after it has 30 years of age on it. For example the sweeter styles from the Pfalz, Rhienhessen and the Nahe don't need nearly as much age as say the wines from the Middle Mosel. It's hotter in the Pfalz, Rheinhessen and Nahe plus the soils are very different, but the main reason is it is hotter and the wines are riper.

So when a sweet German Riesling gets old what happens? A comment I hear a lot is that it loses its sweetness. That is wrong. The sugar level in a wine is locked in from the moment it is bottled and that cannot be changed. Same with the acidity. But our perception of these components changes. As Riesling gets older it gets leathery, gamey and earthy like a forest floor and the sweetness recedes into the background but as I said before the levels as measured by a lab are locked in for the life of the wine. The acid may also be a little lower by our perception but chemically speaking 10 grams of acid is 10 grams of acid. Age can change a wine as much as age can change a person. Heck, some Rieslings even get salty, like we do when we get older. Most Mosel Riesling from the top producers like JJ Prum, Willi Schaefer, Weiser-Kunstler, J.J. Christoffel-Erben can all age easily for up to 30 years. An important factor as well in the aging process is the vintage. Vintages that have high acidity will age longer than ones with lower acidity as acidity is a preservative. But, vintages with high ripeness which usually leads to higher residual sugar levels also can last very long even if they don't have high acidity. Examples of high acid vintages are 2001, 2008, 1971,  1996, 1994, 1975 and 1990. Examples of high ripeness vintages are 2009, 2007, 2005, 1997 and 2006. Examples of vintages when both of these crossover are 2010, 2001 and 1990. All of these vintages ones should feel safe buying from top producers and if the wines have been stored properly.

When you catch an old German Riesling at its apogee it will spin your head like no other wine. For me the 1971 JJ Prum Wehlener Sonnenuhr Auslese GK is the one that spun my head last summer. Creamy, rich, leathery, spicy, saffron like aromas, earthy, perfumed, exotic, youthful yet aged, blah, blah, blah. Needles to say I was waxing poetic.