Back to Enology, Part 4: “Wine is Made in the Vineyard”

And the Myth that Winemaking is More Art than Science: 1 of 2 Posts

With the start of the 2024 harvest, I felt it prudent to address one of my least favorite phrases echoed across the wine industry, “Wine is made in the vineyard.”

Taken literally, and one would think that filled wine bottles sprout from the stems of the vines during the growing season.

Figuratively, there is obviously truth in the phrase. Great quality grapes are required to make great quality wine.

One cannot take poor quality grapes and make stellar quality wine. We can take poor quality fruit and make something “commercially viable,” but great quality is unattainable.

I believe this phrase originated to emphasize the need to take care in the vineyard in order to have the opportunity of producing delicately balanced, delicious wines in the winery. But too often in my career, I’ve heard the phrase used as a replacement for taking care in the winery.

Simply, this cannot be.

Winemaking and enology are subject areas required for making high quality wines. One’s knowledge cannot end with growing good grapes and expecting the fruit will automatically become good quality wine. I’d like to point out that for all the “good quality fruit” I’ve seen in my life, I have tasted a lot (a lot!) of poor quality wine produced. This was at no fault by the grape growers.

In the text, “Understanding Wine Chemistry” (Waterhouse, Sacks, and Jeffery, 2016), it’s cited that “about 6% of the wines submitted to the 2008 International Wine Challenge were considered faulted or flawed.” Approximately 10,000 wines from across the world were submitted that year (Waterhouse, Sacks, and Jeffery, 2016); this is equal to about 600 wines having a noticeable wine flaw (reduction, Brettanomyces, oxidation, or cork taint). These 4 flaws are primarily caused by errors in the winemaking process.

Making wine is a humbling experience. Even when we know what we are doing, we don’t.

It has only been since ~1960s that the industry started emphasizing the production of low alcohol (not fortified), fault-free/flaw-free, varietal, terroir-driven wines. This is what Robert Mondavi was famous for popularizing; he found a way to shift taste preferences in America (Robert Mondavi Winery Tour, 2010). If we think about that sincerely, the wine industry has drastically learned a lot in the last 60-so years of producing table wines. But as I tell every one of my clients, every winemaker will make mistakes in their wine. Every winemaker will produce a wine or wines with flaws. It’s fully possible to make rubbish from something that initially seemed infallible.

This is why understanding the science behind winemaking is as equally important as embracing the artistic nature of wine production.

Enology

Enology is the science of making wine. It’s a collection of our current scientific understanding of wine’s component parts, how they interact in the wine, and how production operations influence those various components. Everything from pH to SO2 has decades of science behind it, creating a beautiful outline of fundamental theories associated with how to make wine.

The very basic of enological components that winemakers can track and follow through production includes

• pH,
• titratable acidity (TA),
• free SO2,
• bound SO2,
• total SO2,
• volatile acidity (VA),
• alcohol concentration,
• malic acid concentration, and
• sugar concentration.

Winemakers with scientific backgrounds and enologists can gain a lot of insight from following these chemical parameters associated with wine.

If you look at the chemical profile of enough wines, you start to identify trends. For example, high potassium retention in a wine tends to be associated with high pH post-fermentation, but with “normal pH’s” and higher TA’s prior to the start of fermentation. These chemical clues lead a winemaker to test potassium levels in the wine, and the potassium concentration then alludes to various ways a winemaker can treat the wine (or future wines) for better chemical balance, color retention (if a red), and stability.

Acid retention and trends associated with acid are additional enological examples that can provide insight into winemaking practices. In some growing regions, acid retention is higher than what is considered “normal” for the U.S. market. In these regions, the enological parameters, pH and TA, start to define just how much higher the acidity tends to be for various wines within a region or a winery. Nationally speaking, if Western red wines are the subjective standard for the American market (due to concentration in the market), then we know any dry red wine that has a TA higher than  4 – 5.5 g/L tartaric acid is going to be outside the realm of expectation for many American wine consumers. In an essence, this is what the DGW Production Guide: Wine Analysis Expected Results attempted to illustrate: for many of these fundamental chemical parameters, there are “norms.”

Some great wines fall outside those norms. I consider those the exception, but not the rule for most standard table wines sold in the U.S.

The French Way

While focusing on wine analytical results may seem nitpicky or unnatural (lacking artistry or creativity), I’d like to point to one of the best winemaking regions of the world: Bordeaux, France.

Bordeaux is a winemaking region that has built its reputation on the quality of the winemaking. In contrast to Burgundy, in which vineyards are coveted for terroir influences on wine quality, Bordeaux wines are produced with an estate identity based on where and how the wines are made. Yes, vineyards still matter, here. But, there is an equal and important emphasis on the winemaking practices, as well.

If we look specifically at Chateau Cheval Blanc (link contains their website with scientific illustrations), one of the first growths of Bordeaux, a simple scan through their wine facts on their website illustrates both the attention to scientific detail in their vineyards and their wines. Vineyard data often includes temperature and rainfall records as well as water balance through the growing season. As we move over to the wine, the various blends for each vintage illustrate the percentages of different varieties that go into that vintage’s blend. There is also an illustration of the vineyard blocks associated with each variety that went into the blend. Further data is provided detailing wine volume and bottle packages. And last, but not least… Many of the vintages include a table that describes the alcohol concentration, total acidity, volatile acidity, pH, total SO2, and sugar content.

For almost every wine, these scientific details are provided.

While this is just one estate within Bordeaux, I’m sure we can find similar data for many of the other premium brands of Bordeaux wine.

It’s something that I’ve anecdotally noted in my interactions with French winemakers and consultants over my career. They often speak with certainty about how to make the wine. This includes directions like, “We use ‘x’ percent of new oak from ‘z’ tonnellerie with minimal intervention on our aging process. We stir lees occasionally to reduce sulfur dioxide or inhibit reductive aromas.” Their instruction sounds very matter-of-fact and simplistic. Intuitive. Perhaps, even, artistic.

But when you continue a conversation of out of curiosity, pressing with more detailed questions, it becomes more and more apparent that the science – the chemistry – behind their wines is regularly monitored by these winemakers. They will talk pH and TA, YAN and potassium ions, or the concentration of acetaldehyde if you manage to ask them the right questions.

To me, this illustrates a deeper appreciation of winemaking beyond the surface of artistry. They simply know that something like TA is important, and don’t require people like me to preach it in various blog posts about enology. *wink, wink* In fact, I have had some internationally-based wine consultants or winemakers ask me, specifically, how American winemakers make wine without knowing certain chemistries in the wine.

(Did you know they pondered this?)

American winemakers and brand ambassadors, in contrast, tend to approach winemaking with a lot more blind faith. If they don’t know what something is, then it must be okay. At the risk of turning people off from this argument, there is a strong capitalistic/business approach to winemaking and enology decisions: we can reduce the cost of wine by reducing as much wine analysis as possible.

Until they have a huge problem. Then, one of two approaches usually ensues:

1. start evaluating the costs and wrap that into the cost per bottle to pass off to consumers.
2. pretend like the problem isn’t there (and usually, add sugar). Pass this off to consumers as good wine.

I’m not writing this to be coy or shameful in any way. Culturally, our industries approach winemaking differently. Both approaches come with pros and cons towards wine quality and business sustainability.

Let’s not assume that talking about science dilutes the intricacies of making wine. Talking about the science enhances the artistry of crafting wines.

I know that so many U.S. winemakers value the perspectives of winemakers from French winemaking regions. The French have prestige, experience, education, and centuries of making renown quality wines. They wow us with their vineyards, soil pits, large Chateaux, and weather records. As winemakers, I would argue we also need to value their (albeit quiet) appreciation for and integration of the science of making wine. Ultimately, without this piece to the puzzle, the puzzle is not complete.

How can we integrate a better appreciation for science in our winemaking practices?

As harvest is around the corner for many of us, I’d like to point out that integrating science into your winemaking practices does not have to be daunting, overwhelming, or difficult. It can be done in pieces over time, and that starts with knowing where to start. It’s easy to get lost in directions from winemakers that emphasize “x” is important or “don’t forget about y” or “I never measure ‘z’ because I don’t need it.” In truth, these absolute statements are never quite absolutely true scientifically.

You can start gaining scientific charisma even if you already feel lost. Here’s how:

• The most important juice chemistries are pH, Brix, and YAN. If you have the ability to measure TA, this will be very helpful for making pivots during the winemaking process, but it will only be valuable if you know where and how to pivot. Find expertise to help you understand when and how to make these pivots; this is the role and skillset of the head winemaker (or a consultant).
• In wine, the most important juice chemistries are pH, free SO2, total SO2, alcohol, and volatile acidity (VA). The analytical components of TA, malic acid concentration, and residual sugar may also be quite valuable for certain types of wine. However, if you needed a starting point, start with the fundamentals: pH, SO2, alcohol concentration, and VA.
• Having easy-to-read, consistent record keeping templates is a good way to encourage yourself to maintain science-based records of your wines. If you need help, DGW offers straightforward record templates for fermentation: Fermentation Records. DGW Members and Clients have access to these templates.
• Most of the time, a winemaker will not find wine analysis important because they simply do not understand why it is important. Even if provided the value, they wouldn’t know what to do with the number. You may not know all the analytical significance associated with making wine, but you can start somewhere. Start small and then be consistent in measuring that component for all of your wines on a regular basis.
  • Nitrogen in Grapes: The concentration of nitrogen in grapes is one of those places where many winemakers put their decisions into that “blind faith” category. Finding the starting YAN seems very complicated for many wineries. I understand why. It’s something that requires a little bit of planning and discipline for obtaining. I put together a small primer, Fermentation Nutrition: What to Know and Why to Know It, that is available to anyone reading this blog post. Over the course of my career, I’ve had access to measuring YAN in-house, I ran YAN measurements for an analytical lab, and I utilized lab services for running YANs for me. This primer explains how I prepared and used lab services that were in California while I lived on the other side of the country. Also, measuring YAN requires the winemaker to understand what to do once that value is received. The primer covers a bit of this, but you can learn more about adjusting nitrogen supplementation during fermentation through Adjusting YAN during Primary Fermentation.
  • Acid Chemistry: pH is one of the most fundamental parts of wine. The fact that wine is a high acid beverage that contains alcohol makes it food safe! And the pH determines all sorts of things in the wine. Learn about pH, how it differs from TA, and become more confident in your pH measurements, here: pH Explained.
  • Sulfur Dioxide Chemistry: Whether you’re new to the wine industry or have been making wine for 30 years, I know very few people who are sulfur dioxide experts. We could all use the review! But finding a good review can be difficult since sulfur dioxide chemistry is so detailed. I like to split this into two topic areas: the scientific theory behind sulfur dioxide, how it works in wine, and the various parts to it (Demystifying Sulfur Dioxide) and how/when to add sulfur dioxide to wine at various stages in production, as well as knowing what the target sulfur dioxide concentration should be for any given wine (Sulfur Dioxide Strategies for Juice and Wine).
  • Volatile Acidity (VA): Once you understand VA, and how helpful this number can be in making winemaking decisions, you will never turn back. VA is the watchful eye over the wine while in tank or barrel. Monitoring VA provides the winemaker with insight as to what is happening. While the analytical test looks difficult, just remember that this analysis is often taught to teenagers so I have faith that we can all accomplish it! Using the Cash Still for Volatile Acidity Analysis.

I know this isn’t the most exhilarating topic to write about. I see the people that fall asleep at my talks when I start talking ions! 😉 When I tell winemakers to pay attention to pH before choosing processes that enhance red wine color, they shake their heads at me. I totally get it. It’s hard to have faith in something that may not be well understood or appears elusive…

But my point in writing this post is to simply say, these topics are the keys to holding up the great pillars of winemaking skills. That, and, we all have access to holding those keys if we would so choose…

NEXT POST! I’ll dive deeper into my “bare minimum” chemical analyses, touch upon microbiology, how [wine] tasting is believing, and introduce my tiers of winemaking excellence! Stay tuned for more enology…

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To quote physicist Lisa Randall, “You can’t have these executive committees or congressional committees that really understand things. I mean, some things are difficult to understand, and not everyone will understand them. And it’s really important for a scientist to be able to at least get the information out there and have that taken into account. There’s also an idea that, you know, when people talk about science, they’re being elitist. That’s not what it’s about. It’s about understanding the world. It’s something that we want to share. I mean, there’s a wonderful universe out there.”

I’ve recently been listening to the Freakonomics series on Richard Feynman, of the greatest scientists of modern-day era. In the last of this three-part series, The Vanishing Mr. Feynman, there was a large emphasis on the decline of trusting scientists or scientific information.

I have to admit that I gravitated to this podcast series as I, like many other scientists in many scientific fields, have recently found the dissemination of scientific information a rather challenging uphill battle.

In the lowest of times, I have considered completely giving up on communicating enology information, the scientific understanding of winemaking. But in the highest of times, I recognize that I have to continue to communicate this information for those that simply do not know the science that strive to learn the science or that strive to make better wines using well-documented winemaking principles.

Therefore, over the next few months, I’d like to address a series of – what I call – “winemaking myths and misconceptions” based on commonly communicated ideas/opinions by industry members that are often veiled as scientific fact or industry standard.

Instead, I’ll work on coming back to what we know scientifically about each of these topics.

Fair warning: the science is usually more complicated, less definitive, and sometimes not yet determined compared to the common discussions you may hear in the winemaking community.

With that in mind, I think it’s important to remember that very fact. The science is complicated. The science may not be definitive as scientists continue to research and test hypotheses (questions) related to winemaking, and as technologies improve giving scientists access to possibility of researching more hypotheses. And sometimes, the science is not yet conclusive. Sometimes scientists do not know the answers we may be looking for. And that’s okay. Even in the face of “not knowing all,” I have managed to advise many of my clients into making a fair share of good quality wines, or award-winning wines. Of course, there have also been growing and learning opportunities during those times in which we don’t know the answers.

Ultimately, it is the continuous stream of new information associated with enology that led me to enology in the first place. Winemaking, after all, is a continuous educational experience.

Would you like to learn with me?

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Resources that Supported this Blog Post:

Robert Mondavi Winery Tour. In person. 2000. More information: https://robertmondaviwinery.com/pages/about-us

Waterhouse, A.L., G.L. Sacks, and D.W. Jeffrey. 2016. Understanding Wine Chemistry. ISBN: 978-1-118-62780-8.

The views and opinions expressed through dgwinemaking.com are intended for general informational purposes only. Denise Gardner Winemaking does not assume any responsibility or liability for those winery, cidery, or alcohol-producing operations that choose to use any of the information seen here or within dgwinemaking.com.