Bones in Wine?

                                Bone dry means there is a miniscule amount of sugar in the wine

Most everyone has probably heard the expression bone dry in reference to wine.  There are no bones in wine, right?    That would be wrong:  China has a wine called “Tiger Wine,” which actually is made with real tiger bones.  OK, now back to bone dry.   This descriptor, along with dry, and off-dry are all three terms used to identify the amount of sugar in a wine.  

So how does sugar get into wine?  Let’s start at the beginning.  In alcoholic fermentation yeasts eat the naturally occurring sugar in grapes and through a process of chemical reactions this sugar is converted to alcohol.  Therefore, the amount of residual sugar (RS) in wine depends upon when the fermentation is stopped. 

In dessert wines (aka sweet wines) fermentation is artificially stopped before all of the yeasts can turn the sugar into alcohol.  This means that these wines have higher sugar levels and lower alcohol.  Conversely, in bone dry wines all of the sugar has been eaten by the yeasts, which in turn means that the wine has a higher alcohol level than dessert wine.   Bone dry means there is very little, if any, remaining sugar. 

Below shows the amounts of RS in the different categories of wines:

                     Bone dry:  0.5% or less RS

                     Dry:  1% RS

                     Off-dry:  2-3% RS

                     Sweet:  3.5-12% RS

                     Dessert:  12-22% RS

An experienced wine drinker can often taste the nuances in a wine’s sugar level, but there are factors that prevent even experts from recognizing the differences between bone dry, dry, and off-dry.   Both tannin and a wine’s acid levels can distort one’s ability to discern RS.   For the novice, even a wine’s ripe fruit aromas or sweet florals can also trick one into thinking the wine has some sugar.

In closing, any grape varietal can be made into a wine that is bone-dry or a dessert wine.  So, how does one know if a wine is bone dry or if there is RS?   Since wineries are not required to put this on the label, most do not.  A good wine store will know.  Many of the better wineries also have “Technical Sheets” available online in which RS amounts are stated.

How Can Wine Smell like a Banana?

                 Banana, green apple & gooseberry profiles are the result of chemical reactions

Why in the world does a wine taste or smell like any fruit other than a grape?  This is the second article in a blog series on the science behind certain flavors and aromas in wine.  This particular article will discuss three fruit flavors/fragrances that can appear in wine.  In fermentation, yeasts eat the sugar in the grapes and convert it to alcohol.  In this process thousands of various chemical compounds are produced.  All three fruit flavors below are a result of these complex chemical processes.

Banana

The banana-like smell and taste is a result of a chemical compound by the name of isoamyl acetate, a by-product of yeasts during fermentation.  The isoamyl acetate also occurs naturally in the banana plant, as well as in pears.  It is present in most wines, however, it is below the threshold of one’s ability to taste it.  It should come as no surprise that artificial banana flavoring is made from isoamyl acetate.

This banana smell and taste can appear in both white and red wines.  Aromatic white wines that are fermented at cooler temperatures (lower temperature enhances the amounts of isoamyl acetate) often display ripe banana notes.  For example, that banana nuances can often be found in Chardonnay, Pinot Gris and Albarino.  Beaujolais is one of the few red wines that has a banana profile.

Green Apple

This flavor and smell profile found in wines is due to the lactic acid which is created during malo-lactic fermentation.  Lactic acid gives off green apple-like scents and flavors, in addition to a creamy mouth feel.  Wines that have pronounced green apple character are classically cool climate dry whites such as Chardonnay, Riesling and Gruner Veltliner.

Gooseberry

Like green apples and banana nuances, this flavor and aroma is not part of the grape.  Gooseberry is created during alcoholic fermentation and is a by-product of yeast activity.   This fruit is typically less sweet so its taste is on the tart side (think pucker),  but gooseberries can also have a slightly floral scent.  Generally found in aromatic whites, gooseberry is classically associated with Sauvignon Blanc (particularly those from cool weather regions such as coastal New Zealand, or France’s Loire Valley).

Keep in mind that each person has a different innate level of tasting various substances.  It doesn’t matter what you taste or don’t taste in a wine.  The only thing that counts is if it pleases you.