Riesling is a white grape variety which originates in the Rhine region of Germany. Riesling is an aromatic grape variety displaying flowery, almost perfumed, aromas as well as high acidity. It is used to make dry, semi-sweet, sweet and sparkling white wines. Riesling wines are usually varietally pure and are seldom oaked. As of 2004, Riesling was estimated to be the world's 20th most grown variety at (with an increasing trend), but in terms of importance for quality wines, it is usually included in the "top three" white wine varieties together with Chardonnay and Sauvignon Blanc. Riesling is a variety which is highly "terroir-expressive", meaning that the character of Riesling wines is clearly influenced by the wine's place of origin.
In 2006, Riesling was the most grown variety in Germany with 20.8% and , and in the French region of Alsace with 21.9% and . There are also significant plantings of Riesling in Austria, northern Italy, Australia, New Zealand, United States, Canada, China and Ukraine. In the countries where it is cultivated, Riesling is most commonly grown in colder regions and locations.
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. However, in 1477, Riesling was documented in Alsace under the spelling Rissling. 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.
It has also been suggested, but not proved, that the red-skinned version of Riesling is the forerunner of the common, "white" Riesling. Most likely, the genetic differences between white and red Riesling are minuscule, as is the case for e.g. the difference between Pinot noir and Pinot gris.
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, honey, rose blossom or cut green grass, and usually a crisp taste due to the high acidity. 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. 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.
The townhall of Bremen, Germany, stores various German wines, including Riesling based wines, in barrel back to the 1653 vintage.
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.
The petrol note is considered to be caused by the compound 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), 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:
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.
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 flavor, 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.
Three common characteristics of German Riesling are that they are rarely blended with other varietals, hardly ever exposed to commercial yeast and usually never exposed to oak flavor (despite some vintners fermenting in "neutral" oak barrels). To this last item there is an exception with some vinters in the wine regions of 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. While clearer in individual flavors 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 is an important consideration in the wine's production with prädikat levels measuring the sweetness of the wine. As 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.
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.
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.
Riesling is on record as being planted in the Alsace region by 1477 when its quality was praised by the Duke of Lorraine. 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. 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.
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 flavors in an Alsace wine will often open up after three years, developing softer and fruitier flavors. Riesling is very suitable for the late harvest Vendange Tardive and the botrytize Sélection de Grains Nobles, with good acidity keeping up the sweetness of the wine.
In 1838 William Macarthur planted Riesling vines near Penrith in New South Wales. Riesling was the most planted white grape in Australia until the early 1990s when Chardonnay greatly increased in popularity. Riesling still flourishes in the Clare Valley, in particular the areas of Watervale and around the Polish Hill River, and the cooler Eden Valley where some sparkling Riesling is produced. The warmer Australian climate produces thicker skinned grapes, sometimes seven times the thickness of German grown grape. 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.
Australian Rieslings are noted for their oily texture and citrus fruit flavors in their youth and a smooth balance of freshness and acid as they age. The botrytized Rieslings have immense levels of flavor concentrations that have been favorably compared to lemon marmalade.
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.
New York Riesling generally has a characteristic effervescent light body with a similarly light, mellow flavor. 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 in popularity to Chardonnay 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 flavors 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..
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.
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 flavors. 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°-18°C (50°-65°F). This differs from red wines that normally ferment at 24°-29°C (75°-85°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. 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 flavor concentrated.
Riesling is almost never fermented or aged in new oak (although large old oak barrels are often used to store and stabilise Riesling based wines in Germany and Alsace). 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°C (52°F). Sweeter Rieslings are often served warmer.
The VIVC lists the following crosses with Riesling as the first parent : Alb de Yaloven, Arnsburger, Augustriesling, Beutelriesling, Bouquetriesling, Dalkauer, Edelmuskat, Ehrenfelser, Feinriesling, Floricica, Frühriesling, Geisenheim 195, Geisenheim 643-10, Geisenheim 643-20, Geisenheim 649, Johanniter, Kocsis Zsuzsa, Manzoni Bianco, Marienriesling, Müller Thurgau, Multaner, Muscat de la Republique, Naumburg 231-52, Oraniensteiner, Osiris, Osteiner, Quanyu B, Rabaner, Rieslina, Riesling Magaracha, Romeo, Weinsberg S186, Weinsberg S195
And as the second parent : Aris, Arnsburger, Aurelius, Dalmasso 12-40, Dona Emilia, Dr. Deckerrebe, Elbriesling, Freiburg 3-29, Geilweilerhof F.S. 4-208-13, Geilweilerhof Koe-49-81, Geilweilerhof Koe-68-107, Geilweilerhof Koe-70-4, Geilweilerhof Koe-70-96, Geilweilerhof Sbl. 2-19-43, Geisenheim 154, Geisenheim 156, Kamchia, Kerner, Lafayette, Misket Varnenski, Negritienok, President Carnot, Rabaner, Rieslaner, Riesling Bulgarski, Ruling, Thurling, Weinsberg S509, Weinsberg S516, Weinsberg S523, Weinsberg S2630
Beregi Riesling, Beyaz Riesling, Biela Grasevina, Dinca Grasiva Biela, Edelriesling, Edle Gewuerztraube, Feher Rajnai, Gentil Aromatique, Gentile Aromatique, Gewuerzriesling, Gewuerztraube, Graefenberger, Graschevina, Grasevina Rajnska, Grauer Riesling, Grobriesling, Hochheimer, Johannisberg, Johannisberger, Karbacher Riesling, Kastellberger, Kis Rizling, Kleigelberger, Kleiner Riesling, Kleinriesler, Kleinriesling, Klingelberger, Krauses, Krausses Roessling, Lipka, Moselriesling, Niederlaender, Oberkircher, Oberlaender, Petit Rhin, Petit Riesling, Petracine, Pfaelzer, Pfefferl, Piros Rajnai Rizling, Pussilla, Raisin Du Rhin, Rajinski Rizling, Rajnai Rizling, Rajnski Ruzling, Rano, Reichsriesling, Reissler, Remo, Rendu, Reno, Renski Rizling, Rezlik, Rezlin, Rezlink, Rhein Riesling, Rheingauer, Rheinriesling, Rhiesling, Riesler, Riesling Bianco, Riesling Blanc, Riesling De Rhin, Riesling Echter Weisser, Riesling Edler, Riesling Gelb Mosel E43, Riesling Giallo, Riesling Grosso, Riesling Gruener Mosel, Riesling Mosel, Riesling Reinskii, Riesling Rhenan, Riesling Rhine, Rieslinger, Rislinenok, Rislinok, Rizling Linner, Rizling Rajinski, Rizling Rajnai, Rizling Rajnski, Rizling Reinskii, Rizling Rynsky, Roessling, Rohac, Rossling, Rosslinger, Ruessel, Ruessling, Russel, Ryn-Riesling, Ryzlink Rynsky, Starosvetske, Starovetski, Szuerke Rizling, Uva Pussila, Weisser Riesling