Sunday, July 22, 2012

FAULTS in Wine; Always Too Much!

Imbalances in a wines character or composition are considered to be a fault(defect) in the wines character & physiology. Good wine should be a complex and balanced living entity where its building blocks are perceived to be in balance with one another.  These principal elements are the same for all wines: alcohol, sugar, acids, polyphenols(tannins & pigments), and grape extract(flavor). Beyond that, all wine is about 80-85% water.  It is the recognition of imbalances in the same base wine that will be tested on the third chapter of my upcoming Wine Educators certification exam, titled "Faults and Imbalances Wine Identification".

Nine(9) glasses of the same base white wine are displayed across the tasting mat, including two un-altered wines.  Of the remaining seven(7) samples, all have been altered to around the threshold of recognition for various composition/tasting faults.  The game is to correctly identify each of these, including the un-altered(base) wine.  On sight, they are all not the same color, as several samples appear to be a darker hue. The noticeably darkest sample is immediately isolated, as it can be only one of two possible faults: excess tannin or oxidation.  If overly tannic, it will won't give away its imbalance by aromas, but by taste where it will quickly dry the top & bottom gums of moisture(protein-based saliva)and have a short, very dry finish by comparison. If oxidized, it will have a distinctive cooked fruit or sherry-like aroma, and upon taste may offer a memory of caramelized sugars with a dry roof of the mouth as well as a short finish when compared to the control sample..
Oxidation may darken wine color early.

Upon nosing the glasses, scent molecules collected thru the nasal cavity are transmitted to the exposed nerve receptors and on to the olfactory bulb of the brain, hopefully triggering a scent memory. Samples that smell of rotten eggs or burnt matches probably are the result of excess hydrogen sulfide, a common wine production additive (sulfur dioxide) that prevents spoilage. Aromas that remind us of vinegar or nail polish remover(ethyl acetate) probably indicate an imbalance in the wines necessary acetic acid once it combines with alcohol(ethanol). This perceived imbalance should 'burn' the nose, and create a flatter wine with an almost pasty body to it. As a fault, this combined character in wines is known as acescence.  Another tainted sample that may feel like a singe of the nasal hairs is excess alcohol, but it won't have the ethyl acetate characters.
Acetone or Ethyl Acetate pronounced aromas

An imbalance of alcohol can create greater 'body' in a wine, and I find that familiar whiff of alcohol to be presented upon an exhale through the nostrils following a taste. By appearance, higher alcohol may also be represented by more defined 'tears' running down the glass following a swirl. Another wine sample with the feeling of greater or richer body would be a wine imbalanced with excess sugar(sucrose).  Because it's sweet component is in greater proportion, this wine should usually taste cloyingly less tart and offer a mouthfeel of richer body.

Not surprisingly, acidity in wine balances out sweetness and bitterness. Of the acids found in grapes, tartaric, malic and citric acids are primary and tend to be 'fixed' in the chemical process of winemaking.  Tartaric acid is the most important among these, as it provides a prominent role in maintaining the stability of any wine. It holds things together, just like cream of tartar. But when it is out of balance, it excessively lowers acid strength(pH), robbing the wine of freshness and usually making wine citric tart.  If we correctly identified our samples, the wine that matches the control sample should be the single taste remaining.  Good Luck!

Many other faults, such as diacetyl(rancid butter) or brettanomyces(barnyard, gamey horse aromas) can also be present in commercial wines.  These can reflect everything from poor hygiene or improper wine stabilization in the cellar and post-production incidents such as heated storage or dirty glassware. Even as volatile and complex compounds compose each and every wine,  individual recognition thresholds for any defect or flaw are unique and vary to each wine taster. Beyond making recognizing trace faults in wine that much more difficult, I also have a limited recognition threshold with any wine when I have had too much!.

The exam is next week at the Societies annual conference, and I'll report results as quickly as I'm advised or become sober, whichever comes first.