MAKING SWEET WINE

In most ways, sweet wines resemble dry (or non-sweet) wines.

The process that makes both wines is fairly simple. Ripe, sweet grapes are crushed, then yeasts change the grapes’ sugar into carbon dioxide and alcohol.

But sweet wines are sweet because, in various ways, some of the sugar in the ripe grapes remains unfermented. (In dry wines, it’s all—or nearly all—fermented.)

Sweetness many ways

• Sometimes the beneficial mold botrytis cinerea envelops the grapes while they still are on the vine and consumes and evaporates their water, further concentrating the sugar in their juice. Sauternes and Barsac achieve their sweetness that way, as do the Tokays of Hungary, the Beerenauslesen of Germany and many Sélections de Grains Nobles of Alsace, late-harvest wines of both Australia and the U.S., and Quarts de Chaume from France’s Loire Valley.

• Sometimes the grapes are left on the vine, long into the winter, and they freeze, so that, at pressing, their water is separated (in the form of ice) from their sugar-laden juice. This happens with German and Austrian Eiswein (ice wine).

• Sometimes the grapes ripen and then are laid on mats to dry and “raisinate” (in Italian, this process is called passito). Over several weeks’ time, the grapes become sweeter and sweeter—too sweet to ferment all the sugar. During fermentation, as the yeasts produce a level of 16%-17% alcohol, they die off, thus ceasing fermentation. What remains in the wine is unfermented sugar (sweetness). Many Italian sweet wines are made this way: for example, recioto della Valpolicella, the vino santo of Trentino and the vin santo of Tuscany.

• Sometimes the winemaker puts a halt to fermentation by creating an environment that is hostile to the yeasts—by bringing the fermenting vat to near-freezing temperatures, for example, or by adding the common preservative sulfur dioxide (SO2). Many late-harvest Rieslings and Gewurztraminers from California are made this way, as are semi-sparkling Moscatos from Italy and other countries. (Adding SO2 is also how winemakers stop fermentation in Sauternes and other late-harvest sweet wines.)

• Sometimes the winemaker stops fermentation by adding distilled alcohol, which kills the yeasts before they have fermented all the sugar in the wine. Port and Madeira come about this way, as does sweet Sherry, the vin doux naturels of southern France (sweet Rasteau, for instance, or Banyuls and Rivesaltes), Sicily’s Marsala, many sweet wines from Australia (fortified Muscats, Ports and Tokays—all called “stickies” down under), and Muscat de Setúbal.

Photo by Corina Rainer on unsplash

The amount of sugar that remains in a sweet wine can range from about 8 percent by volume in a Moscato d’Asti, to 10-12 percent in a Sauternes or a Port, to 12-18 percent in a Hungarian Tokay Aszú.

Port
The world’s two best-known sweet wines are Sauternes and Port. Sauternes is fairly straightforward to understand—white grapes dry out, concentrate and make sweet wine—whereas Port, especially the various sorts of Port, can confuse.

To make it simple, only two types of Port exist, those that are aged in wood and those, in glass.

After Port is made, the thick, super-concentrated, black-red and sweet wine is aged for a period of three to many, many years in either wood casks or glass bottles. If bottles, the Port is a Vintage Port—only about three percent of the entire annual Port production. Vintage Port is made only in excellent or “vintage” years.

Not every year is a “vintage year”—that is, a year of the highest quality worth extra aging. And even when some port shippers “declare” a vintage, others do not. In any case, Vintage Port is expensive, can age upward of 30-40 years and must be decanted before serving.

Ports of the wood
All other ports are Ports of the wood—that is, before being bottled they age in cask for a period of a few, or up to many, years.

Ruby and Premium Ruby, Tawny and Late-Bottled Vintage are all Ports of the wood.

Rubies age about three years in cask. Tawnies age much longer, sometimes as long as 40 years. The older a Tawny is, by and large, the more it costs.

Some of the most delicious Ports are Tawny Ports. Whereas Rubies emphasize power, fruit and plummy intensity, Tawnies play up nutty, woody aromas and tastes. Because much wine has evaporated from the cask during the years in which Tawnies have aged, they also are intensely concentrated in flavor and have a voluptuous feel in the mouth.

Ports such as Late-Bottled Vintage Port are from finer, individual harvests that mature for a brief time in cask and finish their aging in bottle. White Port is something like Sherry and is enjoyed chilled or (all the rage now) with tonic water, as an apéritif.

Interestingly, 40 percent of Port production is bought up by the French—not the British, as many would assume—and most of what the French buy is young Tawny and Ruby Port. The French serve it chilled, as an apéritif.

Because it is both fortified and sweet, once opened, a bottle of Port lasts longer than normal table wine. A Ruby or Tawny can last two weeks to a month; a Late-Bottled Vintage or a Vintage, about a week to 10 days. When the bottle is not in use, refrigeration helps.

Quotable Notable:
"He drank Port as Port should be drunk—a trial of the bouquet; a slow sip; a rather larger and slightly less slow one, and so on; but never a gulp; and during the drinking, his face exchanged its usual bluff and almost brusque aspect for the peculiar blandness which good wine gives to worthy countenances." — From Notes on a Cellarbook, by George Saintsbury