Riesling is a native of Germany, where it’s believed to have been cultivated for at least 500 and possibly as long as 2,000 years. First documented in 1435, the storage inventory of the Counts of Katzenelnbogen lists the purchase of six barrels of riesslingen from a Rsselsheim vintner. It is considered one of the world’s great white wine grapes and produces some of the very best white wines. Today Riesling is Germany’s leading grape variety, known for its characteristic “transparency” in flavor, presentation of terroir, and its balance between fruit and mineral flavours.
In Germany, sugar levels at time of harvest is an important consideration in the wine production. 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. Riesling normally ripens between late September and late November, and late harvest Riesling can be picked as late as January.
Riesling has a powerful and distinctive floral and fruit-like aroma that frequently mixes in mineral elements from its vineyard source and is often described as “racy.” Its high natural level of Tartaric acid enables it to balance even high levels of residual sugar.
In Germany, sweet wines are graded in ascending order of sweetness as AUSLESE, BEERENAUSLESE, and TROCKENBEERENAUSLESE.
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.
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.
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, 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, and more acid to give balance to the flavour.
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.
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.
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”). The beneficial use of “noble rot” was discovered in the late 18th century at Schloss Johannisberg. The 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, but it turned out that the wine made from them had excellent quality.
Riesling is about balance, the subtle interplay of sweetness, fruit, acidity and alcohol. You should really taste other than its upfront fruitiness, a racy acidity that is pleasing to the nerve ends.
The Riesling grape’s ability to retain its acidity while achieving high sugar levels is what creates wines with considerable aging potential.
While clearer in individual flavors when it is young, a German Riesling will harmonize more as it ages, particularly around ten years of age.
Riesling’s naturally high acidity and range of flavours make it suitable for extended aging. International wine experts rate few hundred years old German Rieslings, extremely highly.