Grape Background

Grape Origins

Riesling’s exact origins are unknown, however, genetic testing in 1998 concluded that one of its parent varietals is Heunisch Weiss, known in France as Gouais blanc; the other is unknown.  This makes Riesling related to Chardonnay, Sémillon, Gamay Noir, Melon and Aligoté.[1]  The grape is believed to have been developed in Rheingau, an old cultural region of Germany along the Rhine River, during the Middle Ages, with its first documentation being in 1435.[2] Legend has it that the first Holy Roman Emperor, Charlemagne, (b.747 – d.814) ordered Riesling vines planted on the steep, south-facing hill visible across the Rhine from the palace, because he saw that this was where the snow melted first each spring.​​
  • Germany and Alsace (France)
  • United States
  • ​Australia
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Germany and Alsace (France)​
In 16th century Germany (which in those days included Alsace), Riesling was perceived as a luxury wine as the church and the aristocracy promoted low yields and plantings in the most coveted sites.  Over the centuries, the church and political figures continued to promote the grape, ordering that the grape be planted to the exclusion of, or to replace, other varieties.  This resulted in 19th century German Riesling having wide-spread popularity and comparable prices to that of the Grand Cru of Bordeaux and Burgundy.  During this century, Riesling grapes were first imported to California.
United States

German immigrants were primarily responsible for bringing Riesling grapes to California in the mid-19th century.  There, it was planted in the coastal counties of Northern California, in particular, Santa Clara and Sonoma Counties.  

In Washington State, Riesling was one of the founding grape varieties, with plantings dating back to 1967 in the Yakima Valley.

New York’s Finger Lakes has produced wine since the mid-19th century, however its commercial success is attributed to Riesling.  In 1953, Gold Seal hired Konstatin Frank as a consultant to begin production of vinifera varieties.  Then in 1962, Dr. Frank created Vinifera Wine Cellars which quickly gained respect for making excellent Riesling.  The grapes' success ultimately attracted wine makers and the industry expanded greatly in the 1990s.  This culminated in 1998 when Semi-Dry Rieslings from Dr. Konstantin Frank’s and Fox Run Vineyards each earned a Gold medals in Strasbourg’s Riesling Wines of the World Competition.3
Riesling likely arrived in Australia with the First Fleet (the 11 ships that left Portsmouth, England in 1787, traveled to New South Wales, and established a penal colony) and was one of the original grapes planted.  Its first recorded plantings, in 1838, was near Penrith, New South Wales.  Since then, its popularity in Australia has led the country to have the second-most number of plantings of Riesling, after Germany. 

Growing Characteristics

  • Common Mutations
  • ​Climate/ Rainfall/ Soil/ Disease
  • Harvest
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Roter Riesling:  A very rare mutation causes a red skinned clone while still being a white wine grape. Red Riesling may be found in Germany and Austria with Rheingau region’s Weingut’s (winery) Fritz Allendorf planting the first commercial amounts of Red Riesling
​Growing Characteristics

Climate: Winkler Region I and Ib.  Winkler Region II is considered “warm”.   
  • Cool climates help the grape to keep its acidity.  However, to obtain adequate ripening, ample sunshine is required.  This makes South Aspect (facing) vineyards ideal in colder regions.
  • “Warm”  climates:   “The fruit of region II, has a relatively favorable acid content. Its products were distinct in aroma and pleasant in flavor, soft, and of good quality. They did not possess, however, the balance, richness, or delicacy of the best Riesling wines. The wines from regions III and IV possessed the properties of the variety, but the proportions were even less harmonious than for region II. Aroma and flavor were poorer, and the acidity was definitely low." [5]  -- Albert Winkler, Maynard Amerine 

Soil
  • The variety is adaptable to a wide range of soil types, with highest vigor on fertile soils with high moisture availability. [6]
  • It is most famed when grown in Germany's well-draining, heat-retaining slate, as this helps with ripening.  Slate also does not house phylloxera, and allows grapes like Riesling to be grown on original rootstocks.  
  • When grown in volcanic soils like in Alsaces’ Vosges mountains, Riesling has rounder flavors due to less acidity.   

Clonal Variation
A multitude of clones exist in Germany, yet only a few in Alsace.

  • Budding: Late budding helps Riesling vines resist frost.
  • Ripening:  Mid to late ripening.
  • Vine problems 
    • Prone to botrytis 
    • Prone to coulure 
Harvest
  • A midseason variety.
  • Harvested brix:  18–22 °Bx.
  • pH:  Typically 3.0 to 3.3, though under 2 is not unheard of.  This high acidity allows for less Sulfur Dioxide (SO2) to be used in the winemaking process.
  • Titratable Acidity: 8-10 grams per liter (g/L) and will drop during fermentation by a gram per liter.

Wine Styles

Winemaking [7]

Reductive winemaking is the typical approach to Riesling.  This limits the wine’s exposure to oxygen and preserves the primary fruity aromas and flavors.
  • Pre-fermentation
  • Fermentation
  • Post Fermentation
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Pressing
  • Whole bunch pressing (no desteming)
  • Minimal skin contact is typical, but skin contact is not uncommon.
Fermentation
Slow and low approach to fermentation with temperatures typically ranging from 50°F to 59°F for three to four weeks.
  • Generally no malolactic fermented 
  • Lees contact is possible 
  • Inoculation is more common than wild fermentation.
  • To stop fermentation, once the desired Brix number is reached, the glycol jacket will drop the temperature to stop fermentation.  For botrytised versions, fermentation will stop on its own.
  • In Alsace, fermentation may occur in old oak vessels called fudres, which allows for a small amount of oxidation.  This technique is used to enhance texture and complexity.
  • ​Orange wine: Wine made with prolonged skin contact is another style
Aging
  • Typically bottled young, (within 6 months is common).
  • Riesling may be aged on lees to add texture and flavors. 
  • If aged, low temperature aging occurs in inert vessels like stainless steel.  In Alsace, the traditional method of aging up to a year in large oak vats may be used. 
  • If aged, low temperature aging occurs in inert vessels like stainless steel.  In Alsace, the traditional method of aging up to a year in large oak vats may be used.​​

Styles

Almost all Riesling is single varietal.  Of the single varietal wines
  • Dry (Trocken)
  • Residual Sugar Styles: Halbtrocken/ Kabinett ​/  Spatlese 
  • Sparkling/Sekt
  •  Riesling Alternatives
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Dry (Trocken):
  • German Rieslings labeled Trocken 
  • Alsace, Washington State Riesling labeled “dry,”
  • Most New York Riesling, and most Australian Riesling from Clare and Eden Valleys if not labeled are also dry.

Taste
  • Sugar: Dry to sweet depending on style
  • Body: Light
  • Tannins: None
  • Acidity: High
  • ABV: Less than 10%

Aroma Characteristics 
  • Lemon zest, lime, green apple, nectarine, honey, pineapple, apricot, jasmine
  • Kerosene notes produced by TDN, a compound that increases as grapes are exposed to sunlight, is a distinctive feature of wine made from this grape.
Semi-sweet/Halbtrocken (“Half Dry” or “Off-Dry”)

Sweet and Dessert Wines
  • German Kabinett and Spatlese Rieslings may be sweet.  The labeling terms will provide insight into the style


Sparkling
When making sparkling Riesling, the Charmat (Tank) method is preferred over the traditional method because it helps to preserve the wine's aromatic qualities. 
  • Sekt is a generic German term used for sparkling wine. The grapes do not need to be grown in Germany, however bottles must identify where the grapes are grown.  These styles of Sekt are not typically exported.
  • Deutscher Sekt (German Sekt) is made from grapes grown in Germany and is typically carbonated in the Charmat method.
  • German Sekt b.A. (Sekt bestimmter Anbaugebiete)  specifies the region in which the grapes were sourced, and uses a regional grape varietal like Riesling, Pinot Noir or Silvaner.  Typically it will use charmat method but will occasionally use the Traditional Method.
  • Winzersekt, the highest quality of Sekt, is typically made with Riesling, though it can be made with Chardonnay, Pinot Noir, Pinot Gris, and Pinot Blanc.  The grapes for Winzersekt must be from the producer’s vineyards and the wine must be made in the region in which the grapes are grown.  Additionally, the labeling must include the grape, vintage, and carbonation method.
For more on sket
 Riesling Alternatives
 Dry Riesling
  • Chenin Blanc
  • Pinot Blanc
  • Loureiro (Portugal)
  • Torrontés (Argentina)
  • Malvasia Bianca (Italy)
Sweet Riesling
  • Gewürztraminer
  • Muscat Blanc

Blends

Serving Suggestions

  • Temperature: 38–45°F / 3-7°C
  • Glass Type: White Wine Glass
  • Decant: No
  • Cellar: 10+ years is possible, debatably the best aging potential of any white wine

For dry to off-dry Riesling 

  • Protein
  • Fruits and Veg
  • Herbs and Spices
  • Cheese
  • Desserts
  • Cuisine Styles
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Protein
Chicken, duck, pork (and bacon), shrimp, crab, lobster

Fruits and Vegetables
  • Vegetables: Bell pepper, carrot, eggplant, squash, and red onion
  • Fruit: coconut

Herbs and Spices
Thyme, Cayenne Pepper, Ginger, Clove, Cinnamon, Allspice, Turmeric, Sichuan Pepper, Shallots, Soy Sauce, Sesame, Marjoram, Basil, Rice Vinegar, and Teriyaki Sauce.

Cheese
  • Subtle flavored soft cow’s milk cheese
Insight coming soon
Styles of Cuisine
  • Indian Food including spicy curry
  • BBQ Pork Chop
  • Sushi and Ramen

Major Growing Regions

Cool Regions: Winkler I

  • Rheinhessen and Pfalz
  • Mosel and Rheingau
  • Alsace  (France) and Niederösterreich (Austria)
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Warm Regions: Winkler II

  • Columbia Valley AVA (WA) and Finger Lakes AVA (NY)
  • Clare Valley and Barossa (Australia)
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Sources and Suggested Reading

​Sources
  1. Regner, F. & Stadlbauer, A. & Eisenheld, C.. (2001). Molecular markers for genotyping grapevine and for identifying clones of traditional varieties: Marqueurs moleculaires pour le genotypage de plants de vigne et l'identification de clones de varietes traditionnelles. Acta Horticulturae. 546. 331-342. 10.17660/ActaHortic.2001.546.41.

  2. Sefc, K. M., H. Steinkellner, J. Glössl, S. Kampfer, and F. Regner. “Reconstruction of a Grapevine Pedigree by Microsatellite Analysis.” Theoretical and Applied Genetics 97, no. 1-2 (1998): 227–31. Retrieved from: https://www.academia.edu/27433104/Reconstruction_of_a_grapevine_pedigree_by_microsatellite_analysis 

  3. Finger Lakes Wine Alliance. History. Retrieved January 6, 2021 from https://www.fingerlakeswinealliance.com/trade/history/ 

  4. Wine Australia. (n.d.). Discover Australian Wine. Retrieved January 6, 2021, from https://www.wineaustralia.com/discover-australian-wine/riesling 

  5. Winkler, A.J., Amerine M.A.  Quality of Musts and Wines of California  http://hilgardia.ucanr.edu/

  6. Wine Grape Varieties in California: Riesling. University of California Agriculture and Natural Resources, 2003. http://iv.ucdavis.edu/files/24332.pdf 

  7. Patterson, Tim.  Wine Maker Magazine. https://winemakermag.com/article/221-cool-refreshing-riesling



Additional Reading and Resources
  • “Riesling.” Wikipedia. Wikimedia Foundation, January 4, 2021. https://en.wikipedia.org/wiki/Riesling. 
  • Sweet, Nancy. “Riesling Selections.” FPS Grape Program Newsletter. University of California Davis Foundation Plant Services, October 2009. http://iv.ucdavis.edu/files/121501.pdf. 
  • International Riesling Foundation: drinkriesling.com/ 
  • Wine with Jimmy.  Key Grape Varieties: Riesling (Advanced) for WSET L3 and 4.  March 31, 2020  youtube.com/watch?v=42aXMjzkiqs 
  • Regional Typicity of Cool-Climate Rieslings October 2017   by Demetra M. Perry and Anna Katharine Mansfield https://winesvinesanalytics.com/columns/section/19/article/190169/Regional-Typicity-of-Cool-Climate-Rieslings Copyright © Wines & Vines