Testing & Tasting

Brad Post:

After reading my brothers posting yesterday about “writing on wine” I began to think more about the influences on my own writing.  As a relative newcomer to wine critique, mostly a response to my introduction to wine course, my experiences and insights are tainted from an academic perspective.  Understanding experiences of visitors was my gig for awhile, using a pragmatic approach, meaning it could be purely experimental quantitative or headlong into qualitative methods such as naturalistic observation. In any case my approach to wine appreciation or wine making is muddied from my screwy philosophical position: post-positivism / pre-constructivism.  It’s my own version of a philosophy of science that gives me lots of latitude in understanding things.  These days the experience I am striving to understand is Wine Appreciation and Wine Making.

Wine appreciation is totally different compared to wine making.  You see, as I am making wine a different part of my brain is activated, the part that gets off on science.  When making wine, I am critically looking at the various grape parameters; first I visually inspect the new grapes to make sure they look sound, then I take a good sniff to make sure they smell right (i.e., they don’t have an unpleasant, vinegary odor), and then a more quantitative process begins.  This quantitative process can be as simple as taking a refractor reading, a measurement of how much sugar the grape must possesses, and tests for pH, acidity, and calculations for additions (e.g., yeast, enzymes, tannins, etc.).  Not that wine making is formulaic but there tends to be a lot of science in the cellar these days.

Complementary to my wine making is wine appreciation, the artist side of my brain, where I am encouraged to release my inner-prose. The simple act of attempting to gain a deeper understanding of a wine by first viewing, then smelling, and finally tasting is more difficult than I initially anticipated.  When going through my tasting ritual, instead of identifying specific aromas like grapefruit or honey, I may have a recollection of a time long ago, a faint dusty, earthy quality of a memory and then romantically inspired words to spew forth.  A very different experience from wine making, one might even say there is a qualitative difference between the two.  I enjoy both immensely.

There is harmony between the craft of wine making and the appreciation of wine. Last Thursday I set-up my wine laboratory at the winery and spent the day conducting our regular, periodic wine tests.  My bench, a portable lab table, provided ample space within the cellar to construct a series of wine tests. Every so often wine makers need to assess pH, acidity, and sulfur-dioxide (SO2, aka: sulfites) in the aging wine and adjust, as necessary, to keep the wine happy and protected from micro-critters and oxygen.  In front of me (from left to right) is an array of scientific devices; first is a Titratable Acidity (TA) assembly where, just like in high school chemistry lab, we titrate to determine the acidity in the wine. Crowded next to that is my desktop pH meter where, after calibration, I take pH readings of the wine. And to my far right is a Free SO2 Assembly, another elaborate set-up that might look illicit to someone who hasn’t been in a lab for awhile. (Photo: from my home wine lab).

Lab days tend to be hurry-up-and-wait days.  It goes something like this: take samples from the various fermentation tanks, test for pH, run an acidity test and calculate TA, and then conduct a Free SO2 test (add additional SO2 if required).  Each test takes a different amount of time and precision: pH, quick and easy; TA, about 2 minutes unless I screw up the titration (then I have to re-do it); and finally the Free SO2 test which takes at least 10 minutes to run and a bit more for the math calculations.  All told, it takes a better part of a day to run a series of laboratory tests for only our white wines (I didn’t finish them all either).

I taste, I test, and I try to remember.  Testing is a meditative effort, repeated tasks, calculations and formulas; Tasting is also a contemplative process, smelling, tasting, and feeling.  Each aspect, whether tasting for learning or appreciation, or tasting to assess a fermenting wine, is a complementary process – one without the other and something would be amiss.  There are a lot of things I don’t know about wine – but one thing is certain, I will continue to strive to understand wine from both a scientific point of view and from an artistic/philosophical perspective.

Wine Faults: I Taste Caramel!!!

Brad Posts:

Several months ago we visited a Midwestern winery, tasted several of their wines, and purchased a bottle of “pink” (or blush or rose’) and placed it on our wine rack and forgot about it. A few nights ago we decided to uncork the bottle. As I placed the bottle on the counter Jill remarked on how our pink wine had developed a darker hue (our winemaker alarms were activated!). As I poured the wine into our awaiting glasses we braced ourselves for the inevitable – oxidation!

In white wines, oxidation is evident in yellowing, loss of fruity character, increased bitterness, lifeless aroma, and a has a distinctive caramel aroma (or honey smell); in pink wines, oxidation is evinced similarly and typically has a brownish hue; and in red wines, oxidation shows its ugly head when the pigments in red wine become polymerized and lose their color. White and pink wines are more susceptible to oxidation.

Whatever the cause of oxidation (and there are many) the root of the problem rests mostly on how the wine is handled – read: lack of attention to detail by the winemaker. When processing wine it is important, and there are some exceptions, to keep oxygen away from our must and wine. For the professional winemaker that means a judicious use of inert gas covers during crush and transfers. By flushing a receiving tank (during a racking or transfer) with an inert-like gas such as carbon dioxide, nitrogen or argon, the oxygen is displaced by the heavier gas and our wine is protected during this potentially oxidative situation.

As you might expect, even in the most stringent of conditions some oxygen makes its way into our must/wine. How do winemakers manage oxygen that finds its way into wine? Through the addition of sulfur-dioxide (SO2) – you see it as a message on the bottle that says “sulfites added.” SO2 or “sulfur” serves a couple of important purposes: 1) Antiseptic: at crush, it inhibits the growth of wild yeasts (although yeast can handle SO2 better than bacteria), bacteria (acetic – vinegar and lactic acid bacteria, aka: secondary fermentation), and mold; 2) Antioxidant: sulfur inhibits enzymatic action of polyphenol oxidase and laccase that leads to oxidation.

Pretty simple: SO2 cleans up our must/wine (antiseptic) and SO2 protects our wine from oxygen’s dark side (antioxidant). It is imperative for winemakers to evaluate the levels of SO2 in our wines to ensure they are properly protected. Regularly monitored using a fairly easy test, called aeration-oxidation method, gives accurate readings of how much SO2 is available or “Free” to bind with oxygen -- and informs to whether we need to make an addition!

If the Midwestern wine industry wants to be competitive and taken seriously by those outside of our region we must ensure all of our wines are properly protected against the adverse effects of oxygen.

Sources:

Margallit, Y. (2004). Concepts in Wine Technology. Wine Appreciation Guild, San Francisco, CA.

Dharmadhikari, M.R., and Wilker, K.L. (2001). Micro Vinification: A practical guide to small-scale wine production. Southwest Missouri State University. Mountain Grove, MO.