All posts filed under: wine faults

Big data supports expert wine tasters

In the course of developing software for predicting consumer wine preferences, a Houston-based start up, VineSleuth, shed new light on the abilities of expert wine tasters and the validity of blind tasting assessments. Contrary to popular belief, the company’s VineSleuth metrics, which are based on the work of Chief Science Officer Michael Tompkins and his team, reveal that tasters can consistently identify aroma and flavor characteristics in blind wine evaluations. “We have extensive experimental data which support that expert evaluators have the capacity to precisely identify wine characteristics in blind repeat samples,” said Tompkins whose work spans thirteen years in the field of numerical methods. “During the course of our experiments, our vetted evaluators repeat sample characteristics about 90% of the time,” he says. VineSleuth’s data directly confronts the popular misconception that consistent sensory evaluation of wine is a random occurrence. In developing an algorithm designed to help consumers make wine selections based on personal preference, the company has established a benchmark based on the results of its top-performing tasters (including this author) and intends …

Amorim's Dr. Paulo Lopes.

The Myth Buster: Dr. Paulo Lopes dispels long-held beliefs about cork

When it comes to wine storage, old habits are hard to break. But Dr. Paulo Lopes, Research and Development Manager at Amorim Cork, advises that if temperature and humidity are maintained at the correct levels, wine can be stored upright with no ill effects. In fact, sparkling wine should always be stored upright: a little-known fact that seems lost on many wine experts. During the course of his groundbreaking research, Lopes has seen no difference in the amount of oxygen found in wines that have been stored horizontally or vertically. Using science to debunk the myths that persist within wine culture is liberating largely because the facts can be even more compelling than the misleading maxims. In his recent presentation at the San Francisco Wine School on the reductive and oxidative nature of wine, Lopes made it abundantly clear that, after bottling, the main source of oxygen in wine comes from the cork itself. Atmospheric oxygen doesn’t make its way through the cork (neither does mold, for that matter); rather, the air trapped in cork’s …

Pyrazines: A double-edged sword

Pyrazines—too much of a good thing and they’re a fault; absent in varieties like Sauvignon Blanc and they leave something to be desired. In relation to bitterness, pyrazines can be the source of a flaw or fault, but that’s just one of many ways they can impact wine flavor. Ask any maker of Bordeaux varieties, someone who grows grapes in a marginal climate or experiences a colder vintage, about their concerns, and they’ll surely count elevated pyrazines among them. Admittedly, pyrazines are a double-edged sword. Without them we wouldn’t have the expansive range of wine styles that are possible from Sauvignon Blanc or the markers that help us identify the family of Bordeaux varieties and the likes of Carmenère. But in the extreme, pyrazines dominate wine at the expense of other varietal flavors. We’ve all tasted them—from pungently herbaceous boxwood (the polite reference to cat pee) and jalapeño pepper in Sauvignon Blanc to rank green bell pepper or even weeds in red wines that haven’t achieved physiological ripeness. Pyrazines are the family of volatile organic …

Your glass is half full

Minerality — Without question the most controversial and elusive of wine descriptors.   This comes as no surprise given that the exact definition of what minerals themselves are is still under debate and has been expanded as an element or compound formed through “biogeochemical” processes.  Nutrient or dietary minerals—single elements like manganese, potassium, magnesium, iron, phosphorus, calcium, copper and zinc—are minor components of red wine. White wines have small amounts of iron, calcium, potassium, phosphorus and zinc. A serving of wine can also contain several milligrams of halite, the mineral salt (sodium chloride is the chemical name for salt), and we can accurately describe its taste in wine as saline minerality. Knowing that wine contains minerals, why is describing minerality so problematic?  Largely because aside from halite, nutrient minerals are essentially tasteless. Only when they’re in a highly concentrated liquid form, for example as a dietary supplement, do they taste offensively bitter. But the elusive flavors we describe as “mineral” in some wines can be readily attributed to specific compounds. The two of the most common …

Bitterness: Examing the chemistry behind the taste sensation

Humans are particularly sensitive to bitterness. Thanks to a small but novel family of 30 genes, we can perceive thousands of bitter compounds. Our ability to discern bitter tastes evolved as a way to keep our early ancestors from eating poisonous plants. Bitterness is a taste sensation that we experience when monomeric flavonoid phenols, the compounds that are responsible for bitterness in wine, reach the bitter taste receptor cells on our taste buds. As the receptors send electrochemical signals to the gustatory cortex, we experience bitterness. To what degree determines whether we consider a wine to be merely complex, flawed or faulted. Read the entire article here –Bitterness June July 2016