One of the golden rules about Riesling is that it is never vinified or aged in barrique. The oak flavor that particularly new barrels impart on the wine erases Riesling's subtle flavor profile and hence producers use either large wooden casks that have been lined with tartrates over the years (thus rendering them neutral) or simply go all stainless-steel. But never ever put Riesling in barrique. Never.
As with any rule, there are exceptions. The 2006 Brauneberger Juffer Riesling Auslese** from Günther Steinmetz is one of these exceptions.
The label says that the Riesling was matured in wooden cask ("im Holzfass gereift"). Naturally, I assumed that the wooden cask refers to the Fuder, the traditional 1000 liter barrel of the Mosel region. Only after I had tasted the wine and asked winemaker Stefan Steinmetz for more information about this wine did I learn that the "Holzfass" was, in fact, a small barrique cask. And a new one on top of that!
Stefan Steinmetz decided to ferment some of the Brauneberger Juffer Auslese grape juice in barrique. In order to avoid too much oak character in the final wine the Auslese spent only three months of its fermentation process in new oak. "Of course you can only do that if the wine was fat to begin with", he told me in email. Steinmetz could not mention barrique on the label because in order to do so a wine needs to be matured in new oak for at least nine months by law.
I am sure nine months in barrique would have killed it, no matter how fat this Riesling was to begin with. But I do attribute the smoothness of this Auslese to the three-month fermentation in new oak. Oak flavors from the barrel are imparted to the wine usually during maturation and not during fermentation.
The 2006 Brauneberger Juffer Auslese** im Holzfass gereift had a medium golden color and a pronounced aroma of dried apricots and prunes with a hint of botrytis. Very ripe and concentrated aroma. It was sweet on the palate perfectly balanced by a crisp acidity. Medium(+) intensity of dried apricot, a flinty minerality, quince and grapefruit. Long length, very smooth with a distinctly mineral finish.
Elegantly balanced Riesling. A fine example of acidity and residual sugar creating a texture that is so smooth that it feels almost suspended in air. Impressive!