The Fine Details: The Ability to Blend Art and Science Helps Make Great Wines
April 12, 2010 by Brian C. Clark
When sipping a glass of a fine winemaker’s red blend in front of the fire, it’s easy to appreciate the art that went into that glass.
But anyone who has tried to make wine finds him or herself quickly caught up in what amounts to a science project.
“Winemaking is certainly creative,” said Carolyn Ross, assistant professor of food science at Washington State University and an expert in the sensory analysis of wine. “But at its core, winemaking is a scientific endeavor. What folks often forget is that those two things are not incompatible.”
Take the fine art of fining, for example. Fining agents are substances added at or near the end of the winemaking process in order to improve clarity, adjust flavor, aroma and wine stability. In other words, fining tweaks a wine’s sensory qualities.
And the sensory quality of wine is, of course, what enjoying a glass of great wine is all about: the mouth feel, the unfolding bouquet, the color, the acids, tannins, and other qualities that wine writers deploy armies of adjectives trying to describe. Ross takes a scientific approach to those armies of adjectives be finding ways to quantify their chemical properties and by training panels of wine tasters to communicate the importance of individual sensory qualities.
“Fining is critical for consumer acceptance of white wines as a haze or sediment in the bottle may eventually lead to consumer rejection and economic loss to the winery. Together with racking and filtration, fining agents improve clarity, define aromas and increase shelf life,” Ross and her colleagues wrote in a recently published article in the American Journal of Enology and Viticulture.
But, the researchers add, fining may also “impact the sensory quality of wines,” though how much sensory impact fining has depends upon a complex relationship between the fining compound and the type of wine being fined.
“Fining is definitely where some basic scientific practice is essential to making a good wine,” said Ross.
Ross and her team fined Chardonnay and Gewürztraminer made by a well-known Washington winery which donated the wine to Ross’s team specifically for this series of experiments.
“There’s hasn’t been a lot of research done on the fining of Washington wines,” Ross pointed out. Because wine is so chemically complex, it is very “place specific”: grapes of the same variety grown in different areas produce wines with varying sensory qualities and so research, too, needs to be place specific.
Ross and colleagues tested a wide variety of fining compounds, both those in demand by the industry (bentonite, isinglass, Sparkalloid, and activated carbon) as well as less researched agents (wheat gluten and whole milk).
Ross and team’s paper makes for fascinating reading, as it backs up subjective-seeming words like “fruity” with scientifically quantifiable information: “Isinglass is said to enhance fruity aromas in wines,” the researchers wrote. “In Gewürztraminer, this was demonstrated in that the highest fruit aroma and flavor intensities were observed in the isinglass treatment. The opposite was observed in the Chardonnay, where isinglass had the lowest fruit aroma and flavor intensities.”
Ross is quick to point out that results with fining will vary with the specific grapes and winemaking techniques being used in a particular batch of wine.
“What winemakers should do,” she said, “is bench test small amounts of wine to see the concentration of fining agent that works best. Take small amounts of wine and use different, but controlled doses of fining agents. It’s a good idea to jot down what you used in a notebook, so the winemaker can compare results over time.
“Complicated scientific equipment is not necessary. Visual evaluation of the action of a fining agent should be enough to tell a winemaker which way to go. In three days to two weeks, depending on the fining agent, you’ll be able to see how much settling has occurred. And what you’re going for is the point where there is no more sediment accumulating and you’re seeing the maximum clarity in the wine.”
The take away lesson here is that careful observation aids creativity. Like the poet’s or the novelist’s, the winemaker’s muse is aided by a keen eye for detail.