Laziness doesn't Pay!: The Diversity of Mosel Riesling

The Germans are known to be anything but lazy. When dealing with wines from the Mosel region this “laziness doesn’t pay” develops different meanings. First of all, looking at the steep slopes and observing people climbing the vineyards to tip some shoots makes you realise that this area provides growers with only hard-earned bread. On the other hand, the tremendous diversity of styles and taste profiles of Mosel Riesling demands a lot of attention from the wine lover to capture its essence.

The Climate

The Mosel area is located on the 50° northern latitude, the border for wine growing in the northern hemisphere so far. The region provides the early ripening Riesling with a marginal climate to allow a cool, long and slow ripening period for a maximum of flavour and extract ingress despite moderate sugar development, while keeping acidity high. The climate is really continental, which has some benefits to viticulture, because the rapid temperature fall in autumn enhances fruit ripening, while slowing down vegetative growth and coolness late in ripening can help to conserve delicate aromatics in the berries. However, the higher incidence of summer rainfall in continental climates results in vintage variations.

MIcroclimate

When looking at all the different single vineyards along the serpentine course of the river, it is no surprise that there are tremendous differences in a wine’s taste. Then every difference in orientation toward the sun and wind, proximity to the climatically balancing river, different steepness levels and different soil composition and colour, all make huge differences in microclimate and temperature during the day and night. Most of the metabolic actions and the transport of sugar into the grapes occur at night. The temperature influences the rate of metabolic actions and therefore affects the wine’s taste. It furthermore affects the degradation of malic acidity, which explains why Riesling wines from the Ruwer area with cooler nights have a sharper acidity than wines from the Mosel area. When you talk with Christoph Schaefer (Willi Schaefer Estate), who explains that it is not unusual to have a very long hang time with 150 days from flowering to harvest, it is not surprising that the smallest differences in those mentioned facts have huge effects on a wine’s taste.

To further illustrate this, a comparison between the single vineyards Brauneberger Juffer and Piesporter Goldtröpfchen will help. The latter consists of finely granulated slate soil with high clay content and is therefore deeper and heavier. The vineyard faces south and is shaped like an amphitheatre. The vines are better sheltered than those of the Juffer vineyard and this sheltered site means warmer nights than in any other vineyard of the Mosel valley. The result is a more baroque style, with rounder and juicier acidity. You will seldom find citrus aromas in these wines, but rather multilayered exotic fruits. The Juffer vineyard is higher in skeleton structure and more exposed to the wind. Therefore the microclimate is a hint cooler than in Piesport. The style of its wines is lighter, fresher and more filigree despite profoundness. To make it even more complicated, Wilhelm Haag, the famous grower with big plots in the Juffer Vineyard, writes cask numbers on the labels. Number 6 is a plot in the Juffer Sonnenuhr that faces east and that therefore gets the morning sun, resulting always in lighter wines with the highest mineral impression and ascetic beauty. Number 10 faces west, gets the evening sun and is more opulent and powerful. Others like Willi Schaefer (for example) use different “AP-numbers” when filling different plots of “the same” wine (like Graacher Himmelreich Kabinett).

When growers bottle different wines from the same vineyard at the same Prädikat level, the fourth set of digits in the AP number (05, here) will differ.

Soil

Soil is another important factor when talking about the flavour profile of Mosel Riesling. It predominantly consists of slate, and is high in stone content and low in fertility. This leads to a low nitrogen content in the must, which affects the yeasts metabolism during fermentation, creating different aromas. Riesling from alluvial soils (like in Rheinhessen, for example) is much more fruity and opulent, while Riesling from stony slate soils is more steely and restrained in fruit aromatics and therefore has more mineral impression.

Furthermore, these poor and acidic slate soils influence the pH of the wines. These soils are very old and all chalk contents were washed out during the millennia. (In contrast, the younger slate soils in the “Bündner Herrschaft” in Switzerland are high in chalk content and therefore more alkaline.) How acidity is perceived and therefore how residual sugar is balanced is especially linked to wine pH. In Germany, wines produced on alkaline, chalky soils have a higher pH value and tend to buffer the acidity better. Therefore, Riesling from Rheinhessen for example has in general a pH of around 3.3, while a Riesling from the Mosel generally has a pH around 2.9. As pH is a logarithmic system, this makes a big difference. To illustrate to you the importance of this issue for the balance of residual sugar, a comparison of a Riesling from Rheinhessen with a one from the Mosel will help. The latter can taste perfectly dry with 15 grams per litre residual sugar, while the Rheinhessen Riesling with 7 grams per litre of residual sugar tastes already markedly fruity, despite the same acidity level. To make it clear: It is the generally low pH in Mosel Riesling which explains the unique tension between acidity and sweetness, which is so typical for these wines.

Mosel slate

Soil colour is important for the taste of wine as well. In general you will find predominantly blue/grey slate on the Mosel banks and slopes. However, there is a short part where red slate soil (see picture) is dominating the surface, namely in the villages of Ürzig and Erden. The latest scientific studies in Geisenheim showed that soil colour affects the reflectance of sunlight radiation into the canopy both in quantity and quality. Furthermore, it has an influence on soil temperature as well as on fruit and canopy temperature. In other words, the colour of the soil may be almost as important as its composition, as Hans Reiner Schultz from the Geisenheim University stated. These results are interesting to compare with another study made in Neustadt. There, two wines from red soil were tasted: one from Ürzig/Mosel (iron-rich slate) and one from the 150 km apart Birkweil/Pfalz (reddish breccias). Both wines are growing in very different climates but were surprisingly similar in aromatics, more focused on herbal flowers, spices and less on the classical stone fruit aromatics known for Riesling. It seems that it is no coincidence that the most famous vineyard in Ürzig is called Würzgarten (“spice garden”).

Vineyards near the village of Ürzig

Characteristics of some other famous single vineyards

Bernkasteler Doctor
3.5 hectares

This is a very steep, small vineyard next to the village Bernkastel. Most parts are planted with un-grafted vines on weathered slate soil. The slope is facing southwest and the “Doctor” is known for getting a lot of sun radiation while being cooled down by the wind at the same time. Typical is the exotic, ripe but very pristine fruit character.
Best producers: Geheimrat “J” Wegeler and Reichsgraf von Kesselstatt.

Erdener Prälat
1.5 hectares 

To quote Ernst Loosen: “Prälat is the Richebourg from the Mosel”. There is some truth in it, because the Prälat is one of the richest, most luscious, opulent and sensuous Riesling wines. The vineyard is especially known for producing higher Prädikate, from Auslese upwards. This has to do with the very sheltered, south-facing exposure, which leads to an earlier budding and earlier ripening. Soil is red slate, typically in the villages Erden and Ürzig, giving the wines a spicy note.
Best producers: Dr. Loosen and Dr. F. Weins-Prüm.

Wehlener Sonnenuhr
(44.3 hectares)

Huge vineyard – the best parcels are located on the lower parts close to the Mosel. As the name suggests, it is a south-facing slope – that is why a sundial was built here in the 19^th century. It is not as sheltered as the Prälat or the Goldtröpfchen. The soil is higher in stone content, resulting in elegant wines full of aromatics of yellow fruit and mineralic impression.
Best producers: Joh. Jos. Prüm, Markus Molitor, Selbach-Oster and Reichsgraf von Kesselstatt.

Trittenheimer Apotheke
(68.5 hectare)

South-west facing vineyard on slate soil, sometimes mingled with gravel. Known for tightly structured wines, with piercing acidity and yellow fruit aromatics. Some very good dry wines are made here, by Eva Clüsserath (Ansgar Clüsserath winery).
Other good producers: Grans Fassian, Clüsserath-Eifel and Clüsserath-Weiler. (Sorry, around 30 people in this small village with 1200 citizens are called Clüsserath…)

 Winninger Uhlen
(14.5 hectares)

Terraced parcels and very steep slopes are typical for this vineyard. The different parcels are based on different soil types. There is for example the “Laubach” named after the “Laubach strata” which is slate high in fossil and chalk content. Another example is the “Roth Lay”, which is slate high in iron oxide content. It is poor soil, high in stone content. The most famous producer in this vineyard is Heymann-Löwenstein, known for powerful “dry” wines with a lot of mineral impression. 

Viticulture

The parcelling of vineyards was based on the law of physical division (similar to the French heritage law), which is why some growers had and still have plots no bigger than a towel. There is some new reallocation of land (f.e. in the Piesporter Goldtröpfchen or Graacher Domprobst) meaning that small plots are exchanged between owners, so that people end up with a larger piece of vineyard, which makes their work easier and profitability higher. However, reallocation is complicated and is not done in every vineyard; growers like Joh. Jos. Prüm have plots in the Wehlener Sonnenuhr vineyard with very old, un-grafted vines, and they are therefore not really interested in exchanging their parcels with others.

The small parcelling has many implications. First of all, this and the steep, partly terraced vineyards were the reason why vines used to be trained using the single post system. This has the pragmatic advantage that the grower can easily cross the steep parcels in every direction, but the challenge is the relatively crowded canopy, which results in lower sugar levels in the berries and more risk of botrytis. Quality can only be achieved with selective picking because the grapes on one vine can ripen very differently from another. However, Christoph Schaefer (Schaefer estate) appreciates the system, because he finds that this allows him to pick every Prädikat, resulting in wines with clear flavour differences. Vines trained into trellis systems on wire have the advantage that they are more easily to treat with plant protection, are easier to mechanise and have a more aerated and homogenous canopy.

Willi Schaefer's Graacher Domprobst vines, trained in the single post system

The small parceling and steep vineyards are also the reason why organic winegrowing is not widely spread as in other winegrowing regions, like the Pfalz. First of all, the steep slate slopes often suffer limited water supply and therefore cover crops have to be controlled to avoid stress on the plants. These small and crowded mini plots are often treated with herbicides because other cultivation methods were too tedious and expensive, particularly for second and third-row small growers. Herbicides reduce the activity of soil organisms and this reduces nutrient uptake. These wines can therefore lack complexity. Furthermore, when neighbours spray systemic agents, the drift makes it impossible with those small plots to really practice organic wine growing. Another reason is that for many small wineries, winegrowing is unprofitable and you will find many parcels laying fallow. This causes another huge problem, the increased incident of black rot, which thrives on old and dead wood. Clemens Busch, the famous organic pioneer in the Mosel region, had huge problems with this fungus in 2004. The disease is hardly to control with organic plant protection and he lost over 30 percent of his crop in that year. It was the reason for him to apply additional to organic methods, biodynamic preparations by the way. However, there are some respected growers working with organic methods, such as the aforementioned Clemens Busch in Pünderich, and one of the most respected biodynamic pioneers in Germany, Rudi Trossen in Kinheim-Kindel. The latter is one of the eco-warriors, known for his dry sense of humour, his fabulous ability to philosophize and of course his fantastically authentic wines, some of which are served in the Noma restaurant in Copenhagen.

The Lost "Real" Kabinett

In the past, a Kabinett from the Mosel with 75° Oechsle (9.5% potential alcohol) was physiologically ripe. Today, the same wine from the same vineyard has to have 85-90° Oechsle (around 11% potential alcohol) to reach its full aromatic potential. This has to do with different factors such as global warming and better canopy management. But it seems that systemic plant protection sprays are also to blame, as Georg Meissner (Geisenheim university) and growers like Steffen Christmann (Pfalz) and Daniel Vollenweider (Mosel) presume. To be specific: canopy treated with systemic plant protection stays green and keeps therefore the full assimilation power until the end of the vegetation cycle. Furthermore, it seems that the plants are shocked when they get treated with systemic agents, and physiological ripening stops despite sugar ingress. With organic plant protection, the experience of growers like Christmann and Vollenweider shows that it is possible to lower the potential alcohol content. For that reason, Daniel Vollenweider uses systemic agents only in the beginning of the growing season and uses organic plant protections for the last applications.

However, another reason why the Prädikat Kabinett is in some way outdated is the practice of declassifying an unconvincing Spätlese into a Kabinett.

Wine Styles and Vinification

Wine styles vary from dry to every imaginable sweetness level. For the sweet wines, the incident, development and stage of noble rot (Botrytis) is key for deciding in which Prädikat the wine ends up. Botrytis does not come overnight, attacking the berries and leaving raisins within one hour. No, it is a steady development, dependent on the weather. Best are humid nights which help the fungus develop, followed by dry, warm days, which aid concentration and prevent excessive rot. One can imagine that the regular incidence of noble rot and variation of weather typical in continental climates are factors in determining vintage differences. Noble rot attacks berries and weakens their skin to access sugar and nutrients. This causes tiny punctures through which water evaporates: the berry shrinks and its contents are concentrated. Furthermore, while the fungus feeds on the grape it causes the formation of viscous glycerol and honey-scented aroma compounds, while destroying varietal aromatic compounds such as terpenes. This is the reason why wines made from fully botrytised berries do not have any varietal aromatic definition anymore.

Kabinett wines are made of just ripe grapes with no Botrytis and represent the light and refreshing wine style with a high amount of varietal character. Spätlese is made from later harvest grapes with no or little Botrytis in a very early stage; Auslese has more Botrytis, showing already honeyed tones but still retaining varietal character. Beerenauslese and Trockenbeerenauslese are made from raisined berries; therefore, the wines are highly concentrated, they do not show any varietal character anymore, and the flavours are based on the fabulous honeyed, dried fruit aromatics noble rot is known for.

In general, for sweet wines whole bunch pressing is widespread. This is followed by a long and cool fermentation, often with indigenous yeasts. Depending on the winery’s philosophy, fermentation may take place in stainless steel (e.g. at Joh. Jos. Prüm) or in big wooden casks called “Fuder” with a 1000-litre content (e.g. at Willi Schaefer). Those wooden barrels are often 50 years and older, and can be named “yeast-hotels” too. It is typical that every barrel has its own “natural” yeast population, developing different aromatics, giving more complexity. Furthermore, the slow oxygen ingress can help to control the volatile sulphur compounds developing during fermentation. Natural yeasts are known for producing those compounds, but also the natural low nitrogen content of the grapes here is the reason for those aromatic compounds. To be specific: when must is deficient in nitrogen (which is normal when grapes are grown on low fertile soil and are perchance affected with botrytis) yeast metabolizes sulphur-containing amino acids to get “food”, resulting in volatile sulphur compounds. Those can be fun, because they cause some “mineral” aromatics, but too much causes off-flavours like a smell of rotten eggs. It is the choice of the winegrower to play with these compounds.

At high Prädikate like Beerenauslese or Trockenbeerenauslese, fermentation stops naturally. When to stop fermentation at all other Prädikate in order to keep a balanced amount of residual sugar is a sort of art. As Manfred Prüm (Joh. Jos. Prüm) told me once, the sweetness should taste in youth quite clunky, because it will imbed into the wine during ageing.

Old wooden barrels in the traditional "fuder" size (1000 litre)

Not only sweet wines can be found here. There is much discussion about dry Mosel wines. Some say it is not in the nature of wines with such high acidity and low pH to make balanced dry wines. Others, like producers Daniel Vollenweider, Clemens Busch or Eva Clüsserath, disagree. They see it as a chance to create a new wine style. Furthermore, it has to be acknowledged that the domestic market still prefers dry wines and the classical sweet style of the Mosel is only in favour with real wine connoisseurs in Germany. Therefore, dry Riesling is also economically important for the growers, especially for those who don’t have their focal point on export.

To make a balanced dry wine, some things in viticulture and vinification must change, starting with the yield. Here it is interesting to know that Riesling can show potential and typicity at very different yield levels. For sweet wine, an average yield of 70 hl/ha (from QbA, Kabinett and up to Trockenbeerenauslese) is not unusual for growers like Willi Schaefer or Joh. Jos. Prüm. Sweet Mosel Riesling, especially the lower Prädikate like Kabinett or Spätlese, live from the airy style and lightweight body. Lower yield levels in this case would create just higher sugar gradations, which would weigh down this unique structure. Riesling is the variety that proves that quality doesn’t mean necessary concentration. However, for dry wines you have to restrict the yield to a maximum 40 hl/ha. Here you need more concentration, alcohol and extract to buffer the acidity, since there is no sweetness. Hang time must be long to lower acidity and increase ripeness and a great deal of vineyard work has to be done to keep the grapes healthy, because too much Botrytis in dry wines will make the wine taste dull. Skin maceration of around 8 to 36 hours is used to extract potassium from the skins to increase pH, to buffer acidity. A long fermentation follows, mostly with indigenous yeast, which produces more glycerin and gives the wines more mouth-feel. Malolactic fermentation is not unusual, depending on the vintage. The result is exciting and unique, and produces savoury wines with pure slate mineral impression and saltiness. One great example is the dry Riesling called “Schimbock” from Daniel Vollenweider. The un-grafted vines were planted in the 1970s and are growing on a west-facing slope. After around 24 hours maceration he presses the pulp with an old-fashioned vertical wooden press, resulting in clear juice and allowing oxygen ingress. The wine is for one year in barrel and one year in the bottle before release. It has restrained but very complex and intense aromatics of citrus, grapefruit and a savoury tone, but special is really the texture. Vollenweider got the perfect amount of phenolics into the wine, giving it a delicate weight and length. A great wine with rough edges but full of personality – a real love-it-or-hate-it wine which needs food to shine.

Vintage and Aging

Riesling is known to be a grape variety with a high potential to age, especially the best sweet wines, which seem to be made for eternity. During ageing, all components react in the wine, developing the famous tertiary aromas driven by petrol notes but also of tea, ash and floral tones. This is because acidity reacts with different alcohols, producing different esters, leading to a change in aromatic profile; in addition that acidity is perceived as rounder and less sharp. The residual sugar is reacting with amino acids, leading to the so-called “Maillard” reaction, which you may know from roasting meat in a pan. It produces the famous toasty and caramel aromas, which are also appreciated for example in aged Brut Champagne (and the reason why I don’t like the aged demure Brut Nature Champagne…). The residual sugar is still there, but because of the reactions, the sweetness almost disappears out of the taste profile. A well-aged sweet Auslese has a dry finish and the morbid sugar has the same texture as silky tannins. Such wines are ideally suited for game and other meat dishes – and another tip: try an aged Auslese with oysters and you will be surprised!

There are wineries in the Mosel area were you can drink every vintage, like at Joh. Jos. Prüm, Willi Schaefer and Fritz Haag. The vintage character in these cases is part of the terroir. When you drink a vintage like 1981 (really a nasty one) from one of those estates, it is like super model Miranda Kerr compared to a person who has sticking-out ears but a charming and loveable smile.

To give you a rough overview, a chart with vintage information about the last 10 vintages:

• 2011 -  great classical year, with balanced acidity and average yield. Pure fruit expression.
• 2010 - low sunshine and a lot of rain, wines with incredible high acidity and the first year in decades where de-acidification was used.
  Can be good for sweet wines, but still, they some show very unripe green acidity.
• 2009 -  One of these vintages “of the century” – a ripe vintage, full bodied, ripe acidity (personally, I like more the classical ones with less meat on the bones but higher acidity, like 2011 or 2007).
• 2008 -  average vintage with high acidity, could have a bit more concentration, good for ice wine.
• 2007 – outstanding, classical vintage, ripe but refreshing acidity.
• 2006 - a lot of rain, very early Botrytis, not good for dry wines, some good Beerenauslese and Trockenbeerenauslese (if you like the broader and a bit muddy flavour that botrytised wines can have).
• 2005 -  lush, ripe and creamy wines, very ripe vintage, outstanding vintage.
• 2004 – classical vintage, leaner structure, firm and refreshing acidity, fast developing.
• 2003 -  like everywhere else a very hot year, dry wines are mediocre, outstanding sweet wines because of concentration without Botrytis.
• 2002 – rain before harvest, somewhat soft wines, lacking a bit pristine focus.
• 2001 – top vintage, classical and elegant, ripe and refreshing acidity, perfect sweet wines made for eternity.

Some Politics

The VDP does great work to promote German wine all over the world. However, it is also a big elite club and some members are keen on keeping their competitive advantage without any respect towards young and upcoming wineries. This constrains the further development of this region, in my opinion. It is difficult to make a living with a winery in the Mosel area. Land holdings are small (4 hectare acreage is already big), labour is intensive and the traditional sweet style not popular in the domestic market. For growers it is important to get a chance in export markets. (The top VDP wineries with focus on classical sweet styles have an export share of around 70%!) However, it is of course expensive to work in markets abroad, and for small growers it is impossible to conquer those. As one of the small growers told me, it makes him very angry, that at the Vinexpo in Hong Kong the VDP members claim that every superior German wine carries an eagle on the neck. I can understand the anger of those growers. You should keep in mind that not every great winery is member of the VDP and not every VDP member is great. It is worth looking at growers like the young Jan Klein from the Staffelter Hof in Kröv, classical wineries like Max Ferdinand Richter in Mülheim, the fantastic biodynamic pioneer Rudi Trossen in Kinheim-Kindel or the passionate Suisse Riesling master Daniel Vollenweider in Traben-Trarbach.

Conclusion

The classical sweet Mosel wines are perhaps Germany’s wines best appreciated internationally. It is a wine style that cannot be copied. Nowhere can wines with such a cornucopia of flavours be produced at such a low alcohol level. Nowhere does this balance between sweetness, acidity and mineralic impression dance more effectively in the glass. Their ageing potential can be endless and the wines change personality year by year as they age. This, along with the big diversity of different single vineyards, microclimates and winemaker personalities (each their own philosophy), results in a cornucopia of different wine profiles that have to be conquered as a wine lover. If you are doing that, the effort – not laziness – will pay!

Romana Echensperger has worked for 12 years as a sommelier in high-end restaurants in Germany. In 2005, she was elected “Best Sommelier of Berlin”, working from a list of 1,000 German wines. From 2007 to 2010, she was head sommelier at the three-star restaurant Vendôme near Köln, which was selected “Best Restaurant of Germany”. Echensperger is a second year Master of Wine candidate and passed already the theory exam.