"Working by Hand" (Winemaking)

Winemaking: Riesling At-A-Glance
Most common styles
Still; sweet (some sparkling, mostly in Europe)
Winemaker choices and options
Virtually all winemakers keep intervention to a minimum, preferring resulting wines to be all about the purity of the fruit: minimal if any skin contact, malolactic (ML), lees stirring, etc.
Aging
Stainless steel, concrete, large oak vats (also known as foudres)
Aging potential (yes/no). If “yes,” give range
Yes: Still versions can be drunk young (2-5 years) yet possess the potential to age 20 or more years. Sweet examples can live up to 15 years in California (and decades in Germany’s better appellations)
Presented solo or frequently blended with
A mono-variety wine, Riesling is rarely blended with other grapes, although there have been occasions when small amounts of Riesling can sneak into other white wines discreetly to enhance aromatics.

Leave the fermenting wine must (grape pulp and solids) in contact with the skins before, during and/or after the fermentation.


What it does

It “pops” the fruit character by extracting components from the skins that make the wine opulent and flashy. The downside is that, over time, the wines often brown and oxidize (that is, age) more quickly and can ultimately seem more like sherry than still wine 


Comment

In winemaking, the delicate nature of the Riesling grape requires careful handling during harvesting to avoid crushing or bruising. Without this care, broken skins can release tannin into the juice, giving it a markedly bitter taste and upsetting the wine’s balance. And while there are a few winemakers who purposefully welcome skin contact, they are the exception

What it does

Proponents of wild yeast embrace the unique flavors coming from the “place,” including savory and matchstick-like aromas that many love. Cultivated yeasts are more predictable and can be selected/customized to contribute specific flavors and aromas.


Comment

Some winemakers blend the two, sometimes starting with native yeast and reserving use of commercial yeast only if something does not go right (e.g., fixing a stuck fermentation). Others may create cuvées/cocktails of specific commercial yeasts to achieve a desired flavor profile, since each strain brings something different. As Riesling is all about pristineness and purity, most winemakers opt for cultured yeast with predictably minimal flavor impact (e.g., Champagne yeasts like Prise de Mousse and Epernay II are preferred)

What it does

The cooler the temperature, the slower and longer the alcoholic fermentation lasts. Warmer temperatures equate to shorter and more extractive fermentations.


Comment

To preserve the fresh quality of Riesling, grapes and juice may be chilled throughout the vinification process, immediately following harvest, to preserve the grapes’ more delicate flavors, after the juice has been processed through a press and right before fermentation. During fermentation, the wine is usually kept cool in temperature-controlled stainless-steel tanks kept between 10–18°C (50–65°F)

The wood employed for most wine barrels, used for aging the wine or actual fermentation of the wine in the barrel. Barrel decisions include the type of wood, the amount of toast (when the staves of the barrels are bent over an open flame), size (smaller = higher ratio of wood to wine = stronger oak influence), and the age of the barrels. 


What it does

  • Heavily toasted barrels impart more intense roasted flavors (caramel, molasses, toffee, coffee, and burnt sugar)
  • Oak bestows a waxy, velvety texture and can add a sweet buttercream flavor to the wine 
  • New oak contributes much more flavor than older, previously used oak which, depending on the wine and the grapes, may be a better choice
  • Small (barrique-size) barrel fermentation, at warmer temperatures than those in stainless steel and over shorter increments of time, also imparts a richer, smoother texture to the wine than one that is not fermented in barrel


Comment

Few would dispute that Riesling does not like new oak; new wood generally stomps all over Riesling’s delicate flavors. For those that do employ oak, it is large (foudres and vats), older and distinctly neutral in impact.

Converts wine's malic acid (the sharp acid found in tart green apples) into milder lactic acid (as in sour cream, yogurt, etc.).


What it does

Softens the wine's acidic edge, contributes a velvety smooth texture and can add a strong buttered popcorn flavor. (In red wines, it is mandatory for stability’s sake -- few exceptions.)


Comment

Malolactic fermentation alters the lovely floral characteristics that make Riesling the special grape that it is. Diacetyl (a byproduct of ML, responsible for the buttery popcorn notes) is not important and avoided.

Stirring or agitating the dead yeast cells (lees). During alcoholic fermentation, as the yeast metabolizes the sugar and produces alcohol, dead yeast cells tumble slowly to the bottom of the fermentation vessel, where they can be stirred, aka bâtonnage.


What it does

Adds smooth texture (a rounder “mouthfeel”), additional toasty flavors and an extra dimension of complexity


Comment

Considered particularly important in Chardonnay and Pinot Noir, for those desiring either pure or blended styles with texture, roundness and creaminess. A common practice that originated in Germany, it’s still employed to add roundness and texture to Riesling.

Some grapes, mostly white, are extremely versatile and capable of producing world-class wines in all styles from bone-dry to sparkling to intensely sweet. 


What it does

Targeting a sweetness level for the wine determines its style: dry, off-dry, medium-sweet or sweet.


Comment

With Riesling, its inherent high acidity is key. Acidity provides a counterpoint to sweetness and has a balancing effect upon wines made with measurable residual sugar. Most Rieslings are dry. Many, however, are off-dry, such as Kabinett and Spätlese in Germany, with a snap of sweetness. The exceptions, of course, are intentionally sweet styles, such as Beerenauslese (BA), Eiswein and Trockenbeerenauslese (TBA) in Germany, or vendange tardive (off-dry) and Sélection de Grains Nobles (SGN) in France’s Alsace Riesling, with its susceptibility to botrytis infection. But Riesling’s retention of acidity through the very late stages of ripening allows botrytis-infected grapes to become concentrated through dehydration, yet still retain sufficient acidity to balance the high residual sugar.