Grape Detective: Dry or Sweet Wines

Botrytis or "noble rot" plays a role in making some of the world's finest sweet wines.

The determination of whether to produce a wine that is dry, sweet, or somewhere in-between is made when the winemaker designs the wine and determines the process. When I get the urge to make wine, I think about the possibilities, including grape variety, the attributes of the vineyard, yeast selection (shall I go with commercial yeast or wild?), fermentation approach, equipment to be used, and, of course, sweetness level. I typically elect to make a dry wine, but even then, it is not just a matter of reading sweetness levels on a refractometer to determine when the wine has completed fermentation.

​When it comes to determining sweetness, I have a broad idea in mind. For instance, when I have determined that I want to make a dry wine, I check the wine throughout the fermentation process, not only using tools to monitor the wine’s progress but also by tasting the wine. By sampling the wine as it develops, I can identify the sweet spot, or perfect moment, to halt fermentation. If I halt it too soon, the wine will be sweeter than I intended. If I halt fermentation too late, the wine, while dry, will seem thin and lacking in character. There are no hard-and-fast rules that dictate fermentation timeframes. Each batch is unique, so I mother my fermentations, carefully overseeing each and every aspect of the development of the wine. And, that my friend, is only one of many reasons why making wine is such a hands-on, personal experience.

Some winemakers, when preparing to make wine, have no choice in the matter of sweetness level. An example of this would be if the winemaker is told to work within an established brand or house style so that he can ensure the consistency that his shareholders and consumers have come to expect. Even when a sweetness level has been decided upon, there is a range of the amount of sugar that you will find in the wine. Generally, a dry wine will have less than ten grams per liter of wine. That means you could find nine grams per liter in one dry wine and three grams in another, even though both fall within the dry wine parameter. Sweet wines, the type you would consider dessert wines, often have over thirty grams per liter. There are many wines that fall somewhere between the dry and sweet levels.

Most winemakers do not include nutritional information on their labels, though some do. This puts us all in the position of either tasting the wine for ourselves to assess sweetness or relying on a guide, such as a sommelier or retailer, to give us a feel for the level of sweetness. Also, certain regions, grapes and wine styles are typically expected to be dry or sweet. For instance, if you are buying a Moscato, you are shopping for a sweet wine. If you buy a Barolo, you would be very surprised if it was sweet unless you were buying it in spirits form such as a Chinato.

I was having a conversation with a French winemaker recently and he described the American palate as being drawn to bigger, sweeter Bordeaux style blends rather than the dryer, more austere wines that the French are known to cherish. I had to concede that wines from the Napa Valley and other warm regions in the States tend to be made with riper fruit and therefore have more perceived sweetness, higher alcohol levels and a bigger body than several French wines. Many American winemakers, however, are following a trend toward less sweet, lower alcohol wines by selecting cooler grape growing sites, canopy management, picking grapes before they get overripe, and steering fermentations precisely. This trend has also been going on in recent years in other countries, such as Spain and Argentina, who have a past reputation for big, oaky, alcoholic wines that tend to be sweeter than those of the French.

The sweetness level refers to the amount of residual sugar that remains in the wine after fermentation. A wine’s sweetness level starts in the vineyard, where every vintage has something different to offer in terms of the amount of rainfall and wind, sunshine and heat, and other variables. One of the most important decisions made by the winemaker is when to pick the grapes. If too soon, the wine may taste undeveloped or a bit green. Too late and the wine may be overly rich and alcoholic and sweet. Each vintage has something very different to offer, especially in regions with continental climates, and that is why serious wine buyers pay especially close attention to not only the producer and type of wine but the year of the harvest as well.

Once the grapes are brought into the cellar, the winemaker with the intent of producing a dry wine establishes ideal conditions for the yeast to actively feast on grape sugars. During fermentation, a happy, healthy yeast colony converts the sugars into, mostly, alcohol and carbon dioxide. This typically leaves very little residual sugar in the wine. To produce a sweet wine, the winemaker halts fermentation before the yeast can convert all of the sugars into alcohol and carbon dioxide.

The winemaker has several choices for halting the fermentation, and this basically means that her intent is to kill the yeast colony so it is no longer productive. She can chill the wine, add sulfites or other additives such as grape spirits, or filter the wine, or a combination of techniques. Wine can also be made sweet by adding a sweetener, such as unfermented grape juice, after fermentation and stabilization. This process is known as backsweetening.

When I was explaining the process of driving the sweetness level in a wine to a crowd, someone asked, “If you want to make a sweet wine, why add yeast at all? Then you won’t have to kill the yeast to stop them from eating the sugars.” My answer: grapes, apples, and other fruit have naturally occurring yeast on their skins and other parts, so one way or another, you will have yeast present. When you add commercial yeast to grape juice, it overtakes the wild yeast during fermentation to produce wine that is more stable and offers more predictable outcomes. If you were on a planet where no yeast naturally occurred on fruit and you added no commercial yeast, you would not have alcohol, you would simply have grape juice, because the work of the yeast would not take place. The grape juice you see on the shelf at the grocery store has been stabilized so it does not allow fermentation, and therefore alcohol, to occur.

Sweet wine production starts in the vineyard, where producers grow grapes that are naturally high in sugar and farm them in a way that will concentrate the sugars. Some sweet wine grapes are purposely allowed to become “infected” in the vineyard by a fungus known as Botrytis cinerea or noble rot. Some of the world’s finest sweet wines, such as those produced in the Sauternes region of Bordeaux, capitalize on the help of noble rot to concentrate the finished wine’s acids, flavors and sweetness. While the idea of allowing something to rot may seem off-putting in the world of wine and food, consider that the art of cheesemaking is a process of controlled spoilage. Do you think twice about eating cheese, or yogurt for that matter?

Many people are predisposed to preferring either dry or sweet wines, but both hold a special place at the dinner table. Just the other night Peter and I were at a lovely restaurant in La Jolla, California, and when it was time for dessert, I opted for a sweet wine from vineyards in the Montilla-Moriles wine region in Southern Spain in lieu of the pastry offerings. The Alvear Pedro Ximénez Solera 1927 was my dessert, and I was as happy as a cat jawing a fresh-caught mouse. The Alvear winery was founded in 1729, and the family specializes in fortified wines featuring the Pedro Ximénez grape, also known as PX when it is offered as a single varietal.

The Solera 1927 is one of the world’s best PX wines. It is made using a solera system that was built in 1927, and hence the name of the wine. Solera is a system for blending and aging wine, beer, brandy, vinegar or other liquids so that the finished product integrates the various ages. The moment I laid my eyes on the dessert wine menu and found this offering, I knew it was going to be something special. And it was, with a full body and rich, complex flavors. Honeyed figs, maple, crushed nuts, and caramel come pleasantly to my memory.

If you taste a sweet wine of high quality for the first time, you may be surprised by how fresh and alive it is because the sugar is beautifully balanced by concentrated acidity, flavor and possibly tannins. Any grape variety can be made in either a dry or sweet style, but some varieties are especially versatile and will shine on both ends of the spectrum, such as Chenin Blanc, Sémillon and Riesling. Many sweet white and red wines are blends, such as Tokaji, Port, Sauternes, and Vin Santo Rosso; blends are not included in this list.

If you taste a sweet wine of high quality for the first time, you may be surprised by how fresh and alive it is because the sugar is beautifully balanced by concentrated acidity, flavor and possibly tannins.

You can develop your ability to determine the sweetness of wine by tasting wines at all sweetness levels and categorizing them in line with what trusted resources say about them. Developing your ability to determine sweetness levels is a fine excuse to spend an afternoon with a knowledgeable friend or mentor, tasting through various wines and labelling them as dry, off-dry or sweet. I love setting my palate to one of the driest wines available, and that is a Fino Sherry which is made using the Palomino Fino grape. Fino Sherries have a number of yeast strains to create “flor” involved in their production. The flor creates a thick layer on the surface of the wine in the barrel. You also have flor making its way through the body of the wine and providing lees (dead yeast) at the bottom of the barrel. All this chewing and eating by the flor as it lives and dies gives us a unique and ultra-dry wine with a very distinct character. Most wines enjoyed after a glass of Fino Sherry quickly reveal their level of sweetness.

When determining the sweetness level, keep in mind that residual sugar is only one component of the wine. Perceived sweetness is what we are talking about, with factors such as acidity, tannins, fruit concentration and other aspects influencing the final taste. Specific categories exist for the dry to sweet spectrum, such as dry, off-dry, medium-dry, medium-sweet, sweet, and luscious. You do not have to get that fancy or specific, but giving thought to the sweetness level of a wine helps you select wines that are in line with your particular palate. Thoughtful assessment also increases your knowledge and appreciation of wine.

Wines that are described as “off-dry” or “semi-dry” fall somewhere in the middle of dry and sweet, finishing with a mild and pleasing sweetness. Since our list does not focus on attributes that fall somewhere in the middle of any spectrum, off-dry/semi-dry wines are not included. Sometimes a wine is not technically sweet but gives you an impression of sweetness because the grapes were picked when they were very ripe. This is common in wine regions with hot climates. Oak barrels can also give the impression of sweetness when you pick up the aromas of vanilla or caramel, for example. While our minds link flavors like ripe fruit and vanilla to sweetness, the finish of the wine in your mouth is the best indicator of the sweetness level. If you are working toward a certification and need to identify the sweetness level in a blind tasting exam, consider what one of my teachers advised the class: most wines are considered to be dry.

Dry Varieties

Whites:

Albariño
Arneis
Arinto
Chenin Blanc (dry)
Colombard
Cortese (Gavi)
Dafni
​Furmint (dry)
Garganega (Soave and Gambellara)
Godello
Grechetto
Grenache Blanc
Grillo
Grüner Veltliner
Macabeo
Palomino Fino/Listán Blanco
Pinot Grigio
Prié Blanc
Riesling (dry)
Sauvignon Blanc
Verdejo
Verdicchio
Vermentino
Viura/Macabeo
Torrontés (dry)
Trousseau/Bastardo

Reds:

Aglianico
Bobal/Bovale
Cabernet Sauvignon (cool climate)
Dolcetto
Mourvèdre/Mataro/Monastrell
Nebbiolo
Nero d’Avola 
Petite Sirah
Petit Verdot
Pinotage
Ruchè
Sagrantino
Sangiovese
Syrah/Shiraz
Tannat
Tempranillo
Touriga Nacional

Sweet Varieties

Whites:

Chenin Blanc (sweet)
Gewürztraminer (sweet)
La Crescent
Muscat Blanc/Moscato (sweet)
Pedro Ximénez/PX
Petit Manseng (Jurançon, Pacherenc)
Riesling (sweet)
Sémillon/Semillon (sweet)
Silvaner/Sylvaner (sweet)
Solaris
Zinfandel (white)

Reds:

Brachetto d’Acqui
Muscat (black)
​Liatiko (sweet version)

This is one in a series of Grape Detective blogs featuring the attributes of wine and how your love for a specific wine grape may lead you to discover new grapes with similar characteristics. The focus of the list is grape variety and does not include blends, wine regions, or styles.

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