Morgan & Moore


Making Room for Art in Winery Labs

October 2008
by Jeff Morgan & Daniel Moore
Winery Art
Building an understanding of wine chemistry allows a winemaker to express a more artistic side.

  • Without the art, we've got uninspiring wine. Without the science, we have the potential for spoiled art.
  • Advances in technology for vineyard and winery make rapid, on-site, inexpensive testing an option even for the least scientifically adept.
  • For all but the largest or best-heeled operations, professional labs provide a viable option for more advanced procedures.
It's almost become trite to ask the question: Is winemaking an art or a science? But the question is one that every winemaker needs to think about. Without the art, we've got uninspiring wine. Without the science, we have the potential for spoiled art. Unfortunately, we can't help you find your inner "artiste," but we can help you take stock of what you should be thinking about, analytically speaking, this harvest season.

Equipment technology has advanced winemaking on many fronts. As a result, availability of efficient and rapid laboratory analysis can help you avoid using expensive winemaking techniques to fix your wines. And while some large (or simply wealthy) wineries can invest in a state-of-the-art wine lab--often complete with an enologist--many wineries or winemakers just don't have that option. What kinds of microscopic sleuthing can we do ourselves, and what testing should we shop out to the professionals in the white coats?

Before we answer that, let's look at the big picture. Winemaking is simply not what it used to be. In the old days (meaning before the 1990s) squeaky-clean, sterile-filtered, acidulated wines were the norm. As a result, most wines--both large-scale and boutique--offered a hostile or at least discouraging environment for opportunistic bugs.

More recently, unfiltered, low-acid wines--often sporting a touch of residual sugar--have become popular. They provide a fertile environment for Brettanomyces and other potential spoilage elements. Fortunately, access to an expanding variety of sophisticated lab analyses has increased dramatically in the past 20 years. This has enabled us to improve upon the quality and creativity implicit in the winemaker's "art."

As we monitor wine production, we need to become more vigilant as observers, particularly if we hope to be less interventionist as winemakers. What type of lab capability should your winery have? If your winery's lab skills and ambitions have not progressed past your first Fisher-Price chemistry set, you might want to stick with a nice, simple digital refractometer for measuring vineyard Brix samples. Everything else should be sent to an outside lab.

Know your numbers

It's really hard to make a commercially viable wine without knowing your basic numbers. If you have the desire and ability to run certain in-house lab tests, that's good. Many tests are relatively simple, and a few lab tools will afford most winemakers the ability to test for the basics. Aside from glassware and pipettes, a basic lab set up might consist of: a buret set up for titrations, pH meter, aeration-oxidation apparatus for SO2 analysis, and perhaps a cash still for VA analysis.

It's important to note that lab analysis should start in the vineyard. Brix readings with a refractometer can be accurate if you employ good sampling techniques that cover a broad range of vineyard, but very few of us are making picking decisions based on Brix alone. Pre-harvest wine chemistry is an important first piece to the vintage puzzle. At minimum, make sure you get pH and titratable acidity (TA) on a few vineyard samples when they approach 22º Brix. Do it again a half-Brix prior to your projected pick.

Once the fruit arrives at the crush pad, it's time to get some numbers as soon as possible. For white wines, you'll need to know ammonia and available amino nitrogen, pH, TA, potassium and the organic acid profile. Red wines require the same tests, but you should double-check TA and pH at the end of your cold soak, as these numbers probably will have changed.

If your winery is proficient at the basic lab level, consider purchasing a spectrophotometer. It's a fabulous tool to use with enzymatic tests for malic acid, residual sugar and YAN (yeast available nitrogen). We love having the ability to monitor residual sugar and malic acid levels as often as possible when a wine is nearing completion of primary or malolactic fermentation. For about $4,000, you can get a spectrophotometer that should do 20 samples at a time for $2 an assay.

When you need professional help

But if you are not confident in your winery lab set-up or capabilities, don't hesitate to avail yourself of a professional wine laboratory's services. For most vintners, outsourcing lab work is a great way to track a winery's "microbiological ecosystems." For example, when your wines are finishing fermentation--and certainly prior to bottling--you'll want to know what's going on in tanks or barrels, especially if you're bottling with minimal filtration. West Coast wineries are fortunate to have local heavyweight lab operators that can handle all of their needs. The two largest and best-known--Vinquiry and ETS Laboratories--both offer an in-depth array of microbiological services in addition to a full menu of analytical service.

Even with rigorous cellar sanitation protocols, the potential to encounter some microbiological spoilage always exists. That's why microscopic scans and cultures are essential tools to help all of us know what's going on in the cellar. Relatively new DNA detection analysis offers results with a quick turnaround. These tests are especially useful for detecting Brettanomyces and Pediococcus.

However, the newer tests are not silver bullets and should not replace culturing, microscopic analysis and--in the case of Brettanomyces--testing for 4-ethylphenol and 4-ethylguiacol. The sum of the results from all of theses tests will give you a complete picture and help you develop a strategy for both cellar sanitation as well as finishing your wines.

Ultimately, it's tough to move forward without knowing your basic numbers. It's even harder to produce unfiltered gems with no precise knowledge your wines' microbiology. For small wineries, lab expenses can be significant. Too much analysis will increase your cost of goods. But not having enough analysis can place an entire lot of wine at risk.

Trust your gut and your palate

Where does this leave us regarding the "art" of winemaking? Well, the lab is certainly no substitute for tasting your own wine. If it tastes really good, and the numbers are a little off, you can weigh the pros and cons regarding stability and whether or not to filter from an educated perspective. Indeed, you can make your call based on both science and art. Art can often take precedence, especially when there is a clear understanding of the source vineyard(s), historical tendencies and your cellar's microbiological behavior.

We believe in gut feelings. However, they are most useful when backed up by science. You'll always need your nose and your tastebuds to determine quality. But with a small or a large fortune riding on any given vintage, it's best to know the facts behind the flavors.

Jeff Morgan of Napa Valley and Daniel Moore of Sonoma County are partners in M Squared Wine Consultants,, and jointly own and operate SoloRosa and ZMOR wineries. Morgan also makes two kosher Napa Valley Cabernet Sauvignon wines: Covenant and RED C. To comment on this column, e-mail
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