More musings on chemistry

Can't live with it, can't live without it

I believe that the science of chemistry alone almost proves the existence of an intelligent creator — Thomas Alva Edison

Or perhaps the devil incarnate. Ha… just kidding. You’ll recall that I’m enrolled (incarcerated) in the UC Davis Basic Chemistry for Winemakers course, and that I promised to report on my progress. So, keeping it honest, for me it remains a total mind-sap and devourer of time, and I genuinely resent the hours I put into it—not to mention the recurring and exhausting dreams (seriously) I have attempting to solve some impossible equation calculation.

But something else unexpected is happening.

Watching one of our virtual chemistry lectures recently I actually laughed out loud at a particularly abstruse rant our professor, Grady Wann, was delivering as he attempted to teach us equilibrium constants calculations…

Kc equals the concentration of C raised to the C power times the concentration of D raised to the D power divided by the concentration of A raised to the A power times the concentration of B raised to the B power. The capital letters inside the brackets represent the concentration of the species in moles per liter, and this concentration factor as an exponent component that is equal to the coefficient of that species in the balanced chemical equation. So we have the concentration of the products in the numerator raised to the appropriate power and the reactant concentrations, again, raised to the appropriate power in the denominator.

To the uninitiated, this would have been just so much psychobabble. But in some crazy, improbable way I now actually understood it. And that took my breath away.

Walk the talk. Ethanol molecule T-shirt from The Molecule Store

Over five weeks of endless classes have passed since I last whined about chemistry in this newsletter. In that time we’ve digested 38 more pre-recorded lectures, read 7 more chapters in our eTextbook, completed 9 Dynamic Study Module homework assignments, had 6 live Zoom review sessions, and have sweated 3 more tests. My performance has somewhat improved since the first 2 tests (scores 89 and 81), with new test grades of 93, 84 and 91. I’ve now, somehow, just barely, worked my way into an “A” range as my current overall grade for the course. I find this absolutely remarkable and I brag to myself a lot. To everyone else I still whine.

But what I find even more remarkable is that of the 140 or so students still enrolled in the course—I think we had around 170 to begin with—a good number of these prospective winemakers are Zooming in from other countries and are actually navigating all the nomenclature and verbiage of chemistry with English as their second language. Seriously impressive, seriously humbling.

We began over two months ago attempting to master the basic concepts of general chemistry—atomic structure, chemical bonding, chemical reactions and the Mole, gas behavior and solubility, electrolytes and ions, chemical equilibria, acids and bases, the pH scale and buffers. Now we are merging into organic chemistry and then biological chemistry, and finishing it all up in about three more weeks.

A review slide of one week’s lectures

Even though, admittedly, there is newfound excitement, even power, in actually understanding this daily penance, I fear we are simply jumping from the frying pan into the fire as we now tackle alkanes and aromatic hydrocarbons, oxygen functional group and thiols, carbohydrates, chirality and stereoisomers, carboxylic acids and esters, protein hydrolysis and denaturation—it all seems too much and I’m running out of juice. And I still wonder if some of it is overkill for winemakers, even challenging Grady on one test question about titration that had us doing a calculation that we’d probably never do in a real winemaking scenario—he was not amused.

Whoa, stop the presses! Just after writing the above paragraph I took a break from newsletter writing (which I love) to jump back into chemistry (which I… well, you know how I feel). I listened to Lesson 10.5 Phenolic Compounds and Tannins—one of this past week’s lectures. It began like this:

In this lesson we will get our first glimpse into the wide and wild world of phenolic compounds in wine. Anyone who has spent some time around wine has heard of the importance of phenolic compounds. From our studies [so far] in organic chemistry we know that phenol is the simplest aromatic alcohol having a hydroxyl group attached to a benzine ring.

However, if you were to think that this means that phenolic chemistry is going to be simple, you couldn’t be further from the truth. Phenolic compounds in grapes and wine are an incredibly diverse and complex group of molecules. A great deal of research has been done over the past 50 years, and much has been learned to date. But it has only served to expose how complicated the world of wine phenolics truly is.

Proof right there that we’ve definitely leapt from the frying pan, but, gasp, we’re actually talking about wine! And the rest of the lecture didn’t disappoint—enlightening us on how the non-flavonoid phenolics found in grape pulp, like hydroxycinnametes are good antioxidants, and how the stilbenes like resveratrol have possible anticarcinogenic properties. Then there are the main groups of flavonoids, like anthrocyanins that are responsible for red wine color and stability, and tannins that have a direct correlation to astringency and mouthfeel, and the flavonols with reported anticarcinogenic activity. And then how a phenolic from an outside source, like vanillin from oak barrels, is a phenoaldehyde that plays an important role in flavor and sensory impact,

Sure, it all still sounds just as complicated as before, and is definitely a total mindf--k, but it’s about wine and I perked up instantly. This is what I’ve been after from the beginning! And to learn that after 50 years the guys and gals in white coats still don’t fully understand what’s going on. Well, that just feeds my fantasy that wine is a magical potent—not yet defined empirically by science—with mysteries and delights still to be discovered.

Okay, so I begrudging acknowledge that Grady has successfully built a basic understanding of chemistry in most of us, and without that foundation there would be no way to appreciate the phenolics lecture described above. However, with that knowledge I feel empowered, dare I say excited, to learn its practical application in winemaking. Calculating and controlling molecular SO2 additions, recognizing and rectifying spoilage and oxidation issues, correcting for acid deficiencies or determining the impact of sacrificial tannins or the alchemy of finishing tannins—bring it on!

A frame capture from the Tiny Vineyards movie, J.W. Nickel’s wonderful Pi Acres wine label. Chemistry and math in “practical” application in winemaking!

In reflection, I’m curious as to why I’ve been so resistant, so “anti-learning” to all of this. I’m not sure if it’s because my initial philosophy of winemaking had me siding strongly with the “natural” approach—use as little intervention as possible, especially with chemical additives or corrections, and allow the wine be what it’s going to be—or if it’s just that at my age I no longer wish to be in a “classroom situation” for hours a day (maybe I never did). And then, it might just be that with more than a year of COVID lockdown, the continued sequester of required daily study is the proverbial straw and camel act.

Funny thing is, I decided to take this course not because I required the prerequisite to participate further in the overall Winemaking Certificate—I already had enough science background in college to qualify—but rather because I knew for certain that I wouldn’t remember anything from those halcyon days.

Yet there was something else.

When reading about the Basic Chemistry for Winemakers course on the UC Davis website I came across a background blurb about our instructor, Professor Grady Wann, who is also the overall Director of the Winemaking Certificate program and has decades of personal experience as a winemaker. It included a comment from him which, quite frankly, sold me on the deal:

Minimalist winemaking may be a good basic philosophy, but sometimes it is better to make good wine. Like most winemakers, I started my career with the goal of non-intervention in the winemaking process. The idea that good grapes will turn into good wine with as little manipulation from me was my goal from the start. However, one thing that you learn fairly early on is that the term “winemaker” is just that, a maker of wine. Your role is one of properly caring for the development of the wine all along the way. There are hundreds of little decisions (small “manipulations”) that will result in the wine’s final style.  And whether the wine calls for a little acid here, a little tannin there or even a little filtration, sometimes it is necessary to intervene in order for the wine to be the best it can be.

The numbers are important, but you need to learn to trust your palate. I was a trained organic chemist when I first became a winemaker. As you might expect, I had great regard for the analytical side of winemaking. What I learned along the way is that while the numbers (pH, ethanol %, titratable acidity, residual sugar, phenolic content, etc.) are important, they are not at all the way consumers evaluate wines. Analytical measures provide reasonable parameters and ranges that help guide your decisions as a winemaker, but they do not directly translate into better wines. Learn to trust your palate to tell you what tastes good. And the good news is that practice improves your ability to describe wines. And they call this work!

It feels like Grady is going to deliver, so I shall carry on and somehow get through these final weeks of matriculation. Then we’ll see how it all applies when we get down to the real nitty-gritty.