Turning one into three

Mosel winemaker Kilian Schmitges from Erden embarked on an unusual experiment in autumn 2016, distributing the grapes from his best dry Riesling evenly across three different containers. What makes it special: In addition to a steel tank and an oak barrel, a granite barrel was also used. While the three wines (labelled Steel, Stone and Wood) were still very similar in the first year after bottling, they now reveal significant differences as they mature. Initially, the stainless steel version was ahead of the granite version, but with the appropriate time lag, we have a completely different ranking.

The stone barrel made from a nine-tonne block of granite weighs a good still weighs a good two tonnes with the lid. While granite barrels are already are already used more frequently in Austria, they are almost unknown in Germany. Kilian Schmitges was given the opportunity to try out the 15000 euro barrel for a year.

The expectations were high. “Granite goes very well with Mosel Riesling, there's nothing more natural than stone,” says Schmitges. “Just as the barrique barrel imparts its unmistakable flavour to the wine, the granite barrel is now intended to emphasise the minerality in the wine.”

The wines of the experiment come from a plot of the Erden Treppchen, which is planted with ungrafted vines. On 29 October 2016, the ripe grapes with a must weight of 93 degrees Oechsle were selectively harvested by hand from an area of 5500 m². After a six-hour maceration period and gentle pressing at 0.4 bar for further six hours, the must was distributed to the three containers after natural pre-clarification. After spontaneous fermentation, the wines remained on the full lees until mid-January and on the fine lees until bottling in April.

When we tasted the three Rieslings blind side by side for the first time in June 2017, we found it difficult to assign the wines to the containers in which they were matured. Overall, we found more similarities than differences. At the time, we still favoured Steel, followed by Stone. Wood didn't make it easy for us.

For our second tasting of the wines, which have now matured for six years in the bottle and which we naturally carried out blind again, we repeatedly changed the tasting sequence in several flights in order to eliminate psychological influences on sensory perception as far as possible. This time, the differences were more obvious. Even though the grape material was the same, the three wines described very different development curves. What's more: detached from the discourse on the style of the wines, Wood overtook Stone and Steel, and Stone overtook Steel. This reversed the previous ranking. Steel was quite present early on, but seems to have already passed its peak. Wood was able to improve and has probably now reached its zenith, but still seems to have reserves for some extra years in the bottle.

Stone sits enthroned between Steel and Wood in stoic calm. It is not yet clear how long he will hold his own on the plateau he seems to have found. We suspect that in the longer term it will have at least the ageing potential of Wood. Ageing in granite barrels opens up an interesting alternative to stainless steel for Kilian Schmitges. As expected, Stone showed a striking minerality, albeit somewhat at the expense of the complexity we found in the Wood.

It remains to be seen to what extent the granite barrel will establish itself in the future. We certainly see great potential here, especially when blended with batches from wooden barrels. We recreated a 1:1 mixing ratio in the glass and found this blend to be very promising.