Behind the Cork™ Wine of the Week

IMG_7267.jpg

2015 Gerd Anselmann Pfalz Trocken Riesling ($14)

This German Riesling, from the region of Pfalz, is "Trocken" meaning dry (little to no residual sugar). So, while many German Rieslings are sweet, this is an example of one that, while having little to no sugar content, is not sweet yet still exhibits the sweet fruit flavors of green apple, citrus and peach. An excellent example of a dry German Riesling that has bright acidity. When well chilled, this is a wonderful wine to enjoy with cheeses or a lighter meal. 

Is There a Relationship Between a Wine's Sweetness and Its Alcohol Level?

When choosing a wine, one of the characteristics of interest to you might be its sweetness.  But how can you really tell if a wine has sweet tendencies?  The label may have some sentences on the back label to tell you just a little bit about the wine but rarely will it give an indication of its sweetness. The only quantified characteristic of a wine that is printed on a label is its alcohol by volume (ABV) expressed as a percentage.

From this, you can make some indirect assumptions about a wine's sweetness. Rough rules of thumb say if a wine's alcohol content is 10% or less it will have sweet characteristics.  Wines that are even lower (especially down around 8 or 9 percent) will definitely be sweet. Wines in the 11% to 12.5% ABV range are considered 'off-dry' meaning that there is some notable residual sugar.  If it’s 12.5 percent or higher, the wine will be 'dry' and have little to no perceptible sweetness.

Most wines under 10% ABV will be sweet. Typically, wines such as German Riesling and Italian Moscato fall in this category. Wines in the range of 10.5% to 12.5% include Riesling's from Austria, Australia and the U.S., Sauvignon Blanc, and Pinot Grigio (a.k.a. Pinot Gris).  Then, in the 12.5% to 15.5% range you find Chardonnay, Pinot Noir, Cabernet Sauvignon, Malbec, Sangiovese, Syrah, Grenache and Zinfandel.

But, as previously pointed out, a grape that starts with low sugar levels, and ferments to the point where all the sugar is consumed by the yeast, will result in a wine with lower alcohol levels and little to no residual sugar. So, this is why alcohol levels are not a dependable way of determining a wine's sweetness.

So, while there’s definitely a loose relationship between a wine’s residual sugar and its alcohol level, it’s not a simple relationship.  But you can use the percent alcohol printed on the label as a first indication. Cheers!

Factors that Affect How Sweet a Wine Tastes

Last time, the topic of residual sugar was discussed.  Simply put, residual sugar (RS) is a measure of the sugar (typically in grams per liter) that remains in wine after fermentation.

During an uninterrupted fermentation, the yeast will continue to convert sugar to alcohol until nearly all the sugar is gone or the alcohol level reaches the point that the yeast can no longer live. But, if a wine maker decides to interrupt the fermentation, for example by lowering the temperature to the point where fermentation stops, they end up with wines having higher residual sugar.  That's one way to get a wine with higher residual sugar that tastes sweet.

In the case of sweet dessert wines, the grapes are either allowed to ripen to the point where they have very high sugar levels, dried to create a high sugar to water ratio (raisins) or, in the case of Ice Wine, the grapes are squeezed while frozen so the water does not get extracted and only a highly concentrated sugar solution results. In all these cases, fermentation starts with very high sugar levels so that upon completion of fermentation, there is a high amount of residual sugar.

Another way that wines can seem sweet has little to do with residual sugar.  Wines such as Gewürztraminer and Chenin Blanc are typically thought of as sweet wines.  But whereas a dry (very low RS) Cabernet Sauvignon or Zinfandel will have 0.5 to 1.0 grams per liter (g/L) of residual sugar, a Gewürztraminer can have as little as 1.5 g/L RS and a Chenin Blanc may have around 3.0 g/L RS.  To put this in perspective, a soda pop will typically have around 100 g/L RS!  So, yes, a Chenin Blanc may have twice the RS of a Cabernet, but it's tiny in comparison to a really sweet drink. So why are these wines often considered sweet?  Typically, it's because these wines have big, bright, bold fruit flavors and aromas that we associate with sweetness such as melon, apple, honey, rose, pineapple and grapefruit. Our nose 'fools' us into believing that the wine is sweet when it really doesn't have a significant sugar content.

On the other end of the spectrum are wines such as a sweet Riesling. These can have RS levels in the 40 g/L range. This is definitely sweeter.  One of the reasons that this sweetness is kept in-balance is by the high acidity of these grapes.  You've probably experienced this with lemonade and sodas such as colas which are very high in sugar (> 100 g/L RS) but also have very high acidity. The characteristics of sweetness and acidity balance each other out for a more enjoyable drink.

Another common wine that tends to be sweeter is White Zinfandel. It can have RS levels of 20-40 g/L.  Hence, it makes a great entry-level wine or just a sweet refreshing wine.

And, while we often think only of white wines and rosés as being the ones that can be sweet, even red wines can be a bit on the sweet side. Examples include common red wine blends found in grocery stores with brand names such as Apothic Red, Menage a Trois, Stella Rossa, Yellow Tail and Barefoot.  Even the very popular Meiomi Pinot Noir has 7 g/L of residual sugar.  Now you know why these brands are so popular!

As always, what's most important is that you drink what you like. And, if your taste buds steer you in the direction of sweetness, there are plenty of wines to explore and enjoy. Cheers!

What is Residual Sugar in Wine?

One of the terms that gets thrown around in the wine world is 'Residual Sugar.' But it's not something you are going to read about on a wine's label. So, what is it and why should you care?

Let's take a quick step back and review the basics of the wine making process. Simply put, grapes are grown, picked, crushed and fermented into wine then aged and bottled. It's the fermentation process where sugar comes in. 

Grapes naturally contain various types of sugar. Glucose and Fructose are the two most common sugars, but there are others. Grapes also contain varying levels of sugar. Grapes that are allowed to fully ripen, in warm climates, will contain more sugar than grapes that struggle to ripen in cooler climates. And, wine makers will closely monitor the sugar levels (Brix) in grapes while still on the vine, and choose to pick their grapes when the sugar levels are 'just right' for the grape-type they are growing and their style of wine making.

During the fermentation process, yeast is added to the sugary grape juice. The yeast feeds on the sugar and produces alcohol. If there is any sugar remaining after fermentation, it is referred to as 'residual sugar' (usually noted as RS) and is typically recorded in grams per liter (g/L). This is somewhat of a technical term for a wines' resulting sweetness.

Residual sugar is one component that can contribute to a wine tasting sweet. Next time we'll further explore sweetness in wines.  Until then, Cheers!