The Science of Tasting Wine

I guess you can take the girl our of science (since I now teach Physical Education) but you can’t take the science out of the girl.  My undergrad and graduate degrees in Biology and the way too many years as a microbiologist are ingrained in me.  Although I don’t deal with science on a day to day basis anymore, I actually really do still love the topic.  Using my wonderful Blogshelf ii iPad app, I now subscribe to about thirty blogs.  Although most are about wine, I have sneaked in a few about sports (Go Fins, Rangers, Nets, and Mets) and several about science, genetics being my love.
When I taught AP Biology, I always got a little happier when it came to the point of the school year where we talked about genetics.  Think about it.  Without going into real detail, it is amazing that your mother’s 23 chromosomes came together in the exact perfect way with your father’s 23 to get you.  Every one of us is a a scientific miracle. Not to mention the fact, that scientists are mapping all of our genes to determine future cures for disease or birth defects.  I could go on and on, but since this blog is about wine I’ll just let you read about the Human Genome Project if you want. And it isn’t any different for grapes (except chromosome number) Read  my previous blog entry “Genetics of a Grape: Cabernet Franc” here.
You may be asking yourself “How does wine tie into this blog of science?” Here’s your answer: Tasting wine is a science.  You do not need to be a scientist to enjoy wine.  Anybody can take a sip of wine out of any old glass and decide whether or not they like it. But to truly “taste” wine, you are delving deeply into science.  You may not even be aware of it, and you don’t need to be, but you are.  Tasting involves using your senses.  Everyone knows about senses. The advent of senses is actually credited to Aristotle (384-382 BC).  Much later, it was determined that our senses consist of organs with specialized cellular structures that have receptors for specific stimuli. It is with two of these senses we can truly “taste” wine.

 Some of you may be saying that “tasting” involves three senses.  If we are drinking wine just for the sake of enjoyment, then yes, the third sense of seeing is involved.  But a true tasting should be done blind.  It is important to taste without sight.  Since we subconsciously make decisions about wine by their color.

In reality, color is due to skin contact time and the grape varietal, and it varies. Past experiences have taught us that whites are more light yellow when young and turn darker amber as they age. While reds turn a brickish brown color as they age and are a deeper purple when they are young.  By seeing the color we may make an unconscious predisposition towards that wine.  A true blind tasting is done in black glasses or under red lights without seeing the bottles themselves.  (the bottle shape is a tip off on to what the wine is)
The two senses that are really involved scientifically are smell and taste.
Aroma, or smell, is the most important sense when it comes to food, and therefore wine.  There are actually two ways you smell your wine.  Externally and internally.  Pretty cool, right?  The external sense is called orthonasal olfaction.  This is what is being used when you place your nose in the glass. The second smell, known as retronasal olfaction is from inside the mouth. (it actually means reverse smell) This is what gives you the perception of flavor.  When you say you “taste” cherry in reality you are smelling cherry.  We are not able to taste cherry. This is why we swoosh the wine around our mouth.  It is not to “taste” the flavors but rather to “smell” the flavors.

Taste works by the flavor travels up your “internal nares” located inside your mouth. The “pinching of your nose so you don’t taste something bad” trick doesn’t really work, because those flavor molecules hang around and are there once you release your nose. Gustation is the actual sense of taste and while we are describing flavors that we either enjoy or decide are not pleasurable, it is not taste, it is smell.  To make it even more elaborate wine drinkers use two different terms for these flavors. We use aroma and bouquet.  These are very different things. When someone is discussing the aroma of the wine, they are referring to what comes from the grape itself.  Fruit, herbaceousness, and spice are examples of aroma. When describing bouquet, these are the qualities that came from the winery through the process of fermentation, processing, and aging. An example would be oak or yeast intensity.
Taste, is what occurs on the tongue.  There are only five things that we can taste.  These include sweet, sour, bitter, salty and umami. There has been a long debate as to whether umami could actually be tasted. Finally, in 1985 scientists agreed that we can actually taste the specific amino acid that provides us with the savory taste often described as “brothy” or “meaty.”  I have to agree that “umami” sounds so much cooler than “savory.”
Taste is possible because we have taste buds on our tongue. Our taste buds sit on raised protrusions called papillae. Although there are four types of papillae, only three hold taste buds involved with gustation.  Just as we didn’t know about umami back when we were in school, we were also taught wrong about how we taste. Remember when we were told different areas of the tongue could taste different things?  Well, guess what? That has been proven wrong.  It is now known that all taste buds are capable of tasting all five categories.

In terms of wine, we focus in on only three of these categories.  Sugar can not be detected when it is less than one percent.  Sour comes from the acid in the wine and is described as tart.  Bitterness comes from the tannins created by the seeds and skin and provides an astringent mouthfeel.
Initially, it may be tough to recognize and describe aromas and bouquets in wine. Plus, everyone is not the same.  What I perceive as cherry, may not be what you perceive as cherry.  Additionally, our tolerances for taste vary person to person.  Some people enjoy sour (think sourpatch kids) while others do not.  Some have a higher affinity to tasting bitterness than others.  But the good news is, there is no right or wrong answer and practice does make perfect.  These are wonderful qualities about wine tasting. Although the experience is unique to every individual,  wine doesn’t care about your gender, age (as long as you are 21), status, or any other so called qualifier in life, everyone can sit down and enjoy a glass. I’d like to recommend you do that now, if you aren’t already doing it.  So tell me, what’s in your glass?
`Slainte!