Riesling Grape Variety

 

In 2006, Riesling was the most grown variety in Germany with 20.8% and 21,197 hectares (52,380 acres),[2] and in the French region of Alsace with 21.9% and 3,350 hectares (8,300 acres).[3] There are also significant plantings of Riesling in Austria, Luxembourg, northern Italy, Australia, New Zealand, Finger Lakes, USA, Canada, South Africa, China and Ukraine. In the countries where it is cultivated, Riesling is most commonly grown in colder regions and locations.

History

Riesling has a long history, and there are several written references to the variety dating from the 15th century, although with varying orthography.[4] The earliest of these references dates from March 13, 1435, when the storage inventory of the high noble Count John IV. of Katzenelnbogen in Rüsselsheim (a small principality on the Rhine, close to today's Rheingau) lists "22 ß umb seczreben Rießlingen in die wingarten" ("22 shillings for Riesling vine cuttings for the vineyard").[5][6] The spelling Rießlingen is repeated in many other documents of the time. The modern spelling Riesling was first documented in 1552 when it was mentioned in Hieronymus Bock's Latin herbal.[7]

A map of Kintzheim in Alsace from 1348 contains the text zu dem Russelinge, but it is not certain that this reference is to the grape variety.[4] However, in 1477, Riesling was documented in Alsace under the spelling Rissling.[8] In Wachau in Austria, there is a small stream and a small vineyard both called Ritzling, which are claimed locally to have given Riesling its name. However, there seem to be no documentary evidence to back this up, so this claim is not widely believed to be correct.[9]

Parentage

Earlier, Riesling was sometimes claimed to have originated from wild vines of the Rhine region, without much support to back up that claim. More recently, DNA fingerprinting by Ferdinand Regner indicated that one parent of Riesling is Gouais Blanc, known to the Germans as Weißer Heunisch, a variety that, while rare today, was widely grown by the French and German peasantry of the Middle Ages. The other parent is a cross between a wild vine and Traminer. It is presumed that the Riesling was born somewhere in the valley of the Rhine, since both Heunisch and Traminer have a long documented history in Germany, but with parents from either side of the Adriatic the cross could have happened anywhere on the way.

It has also been suggested, but not proved, that the red-skinned version of Riesling is the forerunner of the common, "white" Riesling.[10] Most likely, the genetic differences between white and red Riesling are minuscule, as is the case for the difference between Pinot noir and Pinot gris.

Longevity

Riesling wines are often consumed when young, when they make a fruity and aromatic wine which may have aromas of green or other apples, grapefruit, peach, gooseberry, honey, rose blossom or cut green grass, and usually a crisp taste due to the high acidity.[11] However, Riesling's naturally high acidity and range of flavours make it suitable for extended aging. International wine expert Michael Broadbent rates aged German Rieslings, some hundreds of years old, extremely highly.[12] Sweet Riesling wines, such as German Trockenbeerenauslese are especially suited for cellaring since the high sugar content provides for additional preservation. However, high quality dry or off-dry Riesling wine is also known to have not just survived but also been enjoyable at an age exceeding 100 years.[13]

The townhall of Bremen, Germany, stores various German wines, including Riesling based wines, in barrel back to the 1653 vintage.[14]

More common aging periods for Riesling wines would be 5-15 years for dry, 10-20 years for semi-sweet and 10-30+ for sweet versions.[15]

Petroleum notes in aged Riesling wines

With time, Riesling wines tend to acquire a petrol note[16] which is sometimes described with associations to kerosene, lubricant or rubber. While an integral part of the aroma profile of mature Riesling and sought after by many experienced drinkers, it may be off-putting to those unaccustomed to it, and those who primarily seek young and fruity aromas in their wine. The negative attitude to aromas of mature Riesling, and the preference for young wines of this variety, seem more common in Germany than in Alsace or on the export market, and some German producers, especially the volume-oriented ones, have even gone so far as to consider the petrol notes a defect which they try to avoid. In that vein, the German Wine Institute has gone so far as to omit the mentioning of "petrol" as a possible aroma on their German-language Wine Aroma Wheel, which is supposed to be specially adapted to German wines, and despite the fact that professor Ann C. Noble had included petrol in her original version of the wheel.

The petrol note is considered to be caused by the compound 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN),[17]which during the aging process is created from carotenoid precursors by acid hydrolysis. The initial concentration of precursors in the wine determines the wine's potential to develop TDN and petrol notes over time. From what is known of the production of carotenoids in grapes, factors that are likely to increase the TDN potential are:[16]

• Ripe grapes, i.e., low yields and late harvest 
• High sun exposure 
• Water stress, which is most likely in regions which do not practice irrigation, and there primarily in certain dry vineyard sites in hot and dry years 
• High acid content 

These factors are usually also considered to contribute to high quality Riesling wines, so the petrol note is in fact more likely to develop in top wines than in simpler wines made from high-yielding vineyards, especially those from the New World, where irrigation is common.

Noble rot

The most expensive wines made from Riesling are late harvest dessert wines, produced by letting the grapes hang on the vines well past normal picking time. Through evaporation caused by the fungus Botrytis cinerea("noble rot") or by freezing, as in the case of ice wine (in German, Eiswein), water is removed and the resulting wine offers richer layers on the palate. These concentrated wines have more sugar (in extreme cases hundreds of grams per litre), more acid (to give balance to all the sugar), more flavour, and more complexity. These elements combine to make wines which are amongst the most long lived of all white wines. The beneficial use of "noble rot" was discovered in the late 18th century at Schloss Johannisberg. Permission from the Abbey of Fulda (which owned the vineyard) to start picking the grapes arrived too late and the grapes had begun to rot; yet it turned out that the wine made from them was still of excellent quality.[18]

Production regions

Riesling is considered one of the grape varieties that best expresses the terroir of the place where it is grown.[19]It is particularly well suited for slate and sandy clay soil.[20]

Germany

Originating in German soil[21] today Riesling is Germanys leading grape variety, known for its characteristic transparencyin flavour and presentation of terroir,[22] and its balance between fruit and mineral flavours. In Germany, Riesling normally ripens between late September and late November, and late harvest Riesling can be picked as late as January.

Three common characteristics of German Riesling are that they are rarely blended with other varietals, hardly ever exposed to commercial yeast[23] and usually never exposed to oak flavour (despite some vintners fermenting in "neutral" oak barrels). To this last item there is an exception with some vinters in the wine regionsof Palatinate (Pfalz) and Baden experimenting with new oak aging. The warmer temperatures in those regions produce heavier wines with a higher alcohol content that can better contend with the new oak.[24] While clearer in individual flavours when it is young, a German Riesling will harmonize more as it ages, particularly around ten years of age.

In Germany, sugar levels at time of harvest are an important consideration in the wine's production with prädikat levels measuring the sweetness of the wine. Equally important to winegrowers is the balance of acidity between the green tasting malic acid and the more citrus tasting tartaric acid. In cool years, some growers will wait until November to harvest in hopes of having a higher level of ripeness and subsequent tartaric acid.[25]

Before technology in wineries could stabilize temperatures, the low temperatures in winter of the northern German regions would halt fermentation and leave the resulting wines with natural sugars and a low alcohol content. According to local tradition, in the Mosel region the wine would then be bottled in tall, tapered, and green hock bottles. Similar bottles, although brown, are used for Riesling produced in the Rhine region.[26]

Riesling is also the preferred grape in production of Deutscher Sekt, German sparkling wine.

Riesling wines from Germany cover a vast array of tastes from sweet to off-dry halbtrocken to dry trocken. Late harvest Rieslings can ripen to become very sweet dessert wines of the beerenauslese (BA) and trockenbeerenauslese (TBA) class.

Alsace (France)

Riesling is on record as being planted in the Alsace region by 1477 when its quality was praised by the Duke of Lorraine.[27] Today over a fifth of Alsace's vineyards are covered with Riesling vines, mostly in the Haut-Rhin district, with the wine produced here being very different from neighboring German Riesling.[28] This is partly from difference in the soil with the clay Alsatian soil being more dominately calcareous than the slate composition of Rheingau. The other differences come in wine making styles, with the Alsatian preferring more French-oriented methods that produce wines of higher alcohol content (normally around 12%) and more roundness due to longer time spent in the steel tanks. Alsace Riesling are never aged in oak barrels. In contrast to German wine laws, Alsatian rieslings can be chaptalized, a process in which the alcoholic content is increased through the addition of sugar to the must.[29]

In contrast to other Alsatian wines, Rieslings in this area are usually not meant to be drunk young, but many are still best in the first years. Rieslings produced here tend to be mostly very dry with a cleansing acidity. They are thick bodied wines that coat the palate. These wines age exceptionally well with a quality vintage ageing up to 20 years. This is beneficial since the flavours in an Alsace wine will often open up after three years, developing softer and fruitier flavours.[28] Riesling is very suitable for the late harvest Vendange Tardive and the botrytize SElection de Grains Nobles, with good acidity keeping up the sweetness of the wine.

In addition to Muscat, Gewurztraminer and Pinot Gris, Riesling is one of the acceptable varieties whose planting is allowed in Alsace's grand cru sites.[30]

Australia and New Zealand

In 1838 William Macarthur planted Riesling vines near Penrith in New South Wales.[31] Riesling was the most planted white grape in Australia until the early 1990s when Chardonnay greatly increased in popularity.[29]Riesling still flourishes in the Clare Valley, in particular the areas of Watervale and around the Polish Hill River, and the cooler Eden Valley and High Eden regions. Riesling is also being grown with increasing popularity in the Western Australian regions Albany, Frankland River and Porongorup. The warmer Australian climate produces thicker skinned grapes, sometimes seven times the thickness of German grown grape.[24] The grapes ripening in free drain soil composed of red soil over limestone and shale, producing a lean wine that as it matures produces toasty, honeycomb and lime aromas and flavours. It is common for Australian Rieslings to be fermented at low temperatures in stainless steel tanks with no oxidation of the wine and followed by earlier bottling.[32]

Australian Rieslings are noted for their oily texture and citrus fruit flavours in their youth and a smooth balance of freshness and acid as they age. The botrytized Rieslings have immense levels of flavour concentrations that have been favorably compared to lemon marmalade.[33]

Riesling was first planted in New Zealand in the 1970s and has flourished in the relatively cool climate of the Marlborough area and for late harvests in the Nelson region. In comparison to Australian Riesling, New Zealand produces lighter and more delicate wines that range from sweet to dry.Home of cool climate wines, Central Otago, has recently emerged as another area producing terroir driven wines.

Austria

Riesling is the second leading white grape varietal after the indigenous Grüner Veltliner.[34] Austrian Riesling is generally thick bodied, coating the palate and producing a strong clarity of flavour coupled with a mouthwatering aroma. A particular Austrian Riesling trademark is a long finish that includes hints of white pepper. It flourishes in the cool climate and free-draining granite and mica soil of the Wachau region where Austrian wine laws allow for irrigation. With levels normally around 13% it has a relatively high alcohol content for Riesling and is generally at its peak after 5 years.[32] Austrian Riesling is not known for its sweetness and is mostly dry with very few grapes affected by botrytis.

United States

In the late nineteenth century German immigrants brought with them Riesling vines, named Johannisberg Riesling to qualify them as œlegitimate German Riesling. New York, particularly in the Finger Lakes region, was one of the earliest U.S. producers of Riesling. Plantings started to appear in California by 1857 and followed in Washington State in 1871.[32]

New York Riesling generally has a characteristic effervescent light body with a similarly light, mellow flavour. The wine can be dynamic though rarely robust, and ranges from dry to sweet. New York is also a notable producer of Riesling based Ice Wine, although a large majority of New York Ice Wine is made from Vidal Blanc and Vignoles.

In California, Riesling lags far behind Chardonnay in popularity and is not as commonly planted. A notable exception is the growing development of high quality Late Harvest dessert wines. So far, the Late Harvest wines most successfully produced are in the Anderson and Alexander Valleys where the weather is more likely to encourage the needed botrytis to develop. The Riesling that does come out of California tends to be softer, fuller, and having more diverse flavours than a "typical" German Riesling.

In the Pacific Northwest there is a stark contrast in Riesling production. The grape is currently on the rise in Washington State but on the decline in neighboring Oregon. Riesling from this area ranges from dry to sweet, and has a crisp lightness that bodes well for easy drinking. Often there will be an easily detectable peach and mineral complex. Some Washington State winemakers, such as Chateau Ste. Michelle, are adapting German-style Riesling production methods, and even partnering with well-known German vintners like Dr. Ernest Loosen to create specialty wines such as the Eroica Riesling. With annual productions of over 600,000 cases a year, Chateau Ste. Michelle is the worldwide leader in the production of Riesling wines by volume. In 2007 Pacific Rim Winemakers, another Pacific Northwest winery and owned by Randall Grahm of Bonny Doon, has built the first wine facility in Red Mountain AVA dedicated completely to Riesling production.[35]

Canada

In Ontario, Riesling is commonly used for Icewine, where the wine is noted for its breadth and complexity.[33]Niagara is a major producer of ice wine in general, putting it neck-and-neck with Germany. Late Harvest wines and some sparkling wines are produced with Riesling in Niagara but it is table wines from dry to off-dry that hold the largest share of production. The climate of the region is typically quite warm in the summertime which adds a layer of richness in the wines. It is interesting that the founder of St. Urbanshoff in the Mosel, Herman Weiss, was an early pioneer in Niagara's modern viticulture, selling his strain of Mosel clone Riesling to many producers in west Niagara (these vines are well over 20 years old now). This clone and Niagara's summer heat make for uniquely bright wines and often show up in interesting dry styled versions. Many producers and wine critics will argue that Niagara's best offerings come from the Niagara Escarpment region which encompasses the Short Hills Bench, 20 Mile Bench and Beamsville Bench.

In British Columbia, Riesling is commonly grown for use in Icewine, table wine, and sekt style sparkling wines, a notable example of which is Cipes Brut.

Other regions

Riesling is also widely grown in South Africa, Chile and Central Europe, particularly Romania and Moldova.

Production

In wine making, the delicate nature of the Riesling grape requires special handling during harvesting to avoid crushing or bruising the skin. Without this care, the broken skins could leak tannin into the juice, giving a markedly coarse taste and throwing off balance the Riesling’s range of flavours and aromas.

A wine that is best at its freshest. states, the grapes and juice may be chilled often throughout the vinification process. Once, right after picking to preserve the grapes' more delicate flavours. Second, after it has been processed through a bladder press and right before fermentation. During fermentation, the wine is cooled in temperature controlled stainless steel fermentation tanks kept between 10 and 18 °C (50 and 64 Â°F). This differs from red wines that normally ferment at 24 to 29 °C (75 to 84 Â°F)

Unlike Chardonnay, most Riesling do not undergo malolactic fermentation. This helps preserve the tart, acidic characteristic of the wine that gives Riesling its thirst-quenching quality. (Producers of Sauvignon Blanc and Pinot Grigio often avoid malolactic fermentation for the same reason.) Riesling is often put through a process of cold stabilization, where the wine is stored just above its freezing point. The wine is kept at this temperature until much of the tartaric acid has crystallized and precipitated out of the wine. This helps prevent crystallization of the acid (often called "wine diamonds") in the bottle.[36] After this, the wine is normally filtered again to remove any remaining yeast or impurities.

In viticulture, the two main components in growing Riesling grapes are to keep it "Long & Low" meaning that the ideal situation for Riesling is a climate that allows for a long, slow ripening and proper pruning to keep the yield low and the flavour concentrated.[19]

With food

Riesling is a versatile wine for pairing with food, because of its balance of sugar and acidity. It can be paired with white fish or pork, and is one of the few wines that can stand up to the stronger flavours and spices of Thai and Chinese cuisine.[37] A Riesling's typical aromas are of flowers, tropical fruits, and mineral stone (such as slate or quartz), although, with time, the wine acquires a petrol note as mentioned above.

Riesling is almost never fermented or aged in new oak (although large old oak barrels are often used to store and stabilize Riesling based wines in Germany and Alsace).[38] This means that Riesling tends to be lighter weight and therefore suitable to a wider range of foods. The sharp acidity/sweetness in Rieslings can serve as a good balance to foods that have a high salt content. In Germany, cabbage is sometimes cooked with riesling to reduce the vegetable's smell.

As with other white wines, dry Riesling is generally served at a cool 11 Â°C (52 Â°F). Sweeter Rieslings are often served warmer.[39]

Clones

There exists a large number of commercial clones of Riesling, with slightly different properties. In Germany, approximately 60 clones are allowed, and the most famous of these have been propagated from vines in the vineyards of Schloss Johannisberg. Most other countries have sourced their Riesling clones directly from Germany, but they are sometimes propagated under different designations.

NOTES AND REFERENCES