We live in a golden age of wine, thanks in part to thirsty millennials and Americans seemingly intent on out-drinking the French. Yet for all its popularity, the sommelier's world is largely a mysterious one. Bottles on grocery store shelves come adorned with whimsical images and proudly proclaim their region of origin, but rarely list ingredients other than grapes. Meanwhile, ordering wine at a restaurant can often mean pretending to understand terms like "mouthfeel," "legs" or "bouquet."
"I liked wine the same way I liked Tibetan hand puppetry or theoretical particle physics," writes journalist Bianca Bosker in the introduction to her 2017 book Cork Dork, "which is to say I had no idea what was going on but was content to smile and nod."
Curious about what exactly happened in this shrouded world, Bosker took off a year and a half from writing to train to become a sommelier, and talk her way into wine production facilities across the country. In the end, Bosker learned that most wine is nowhere near as “natural” as many people think—and that scientific advances have helped make cheap wine nearly as good as the expensive stuff.
"There's an incredible amount we don't understand about what makes wine—this thing that shakes some people to the core," Bosker says. In particular, most people don't realize how much chemistry goes into making a product that is supposedly just grapes and yeast, she says. Part of the reason is that, unlike food and medicines, alcoholic beverages in the U.S. aren't covered by the Food and Drug Administration. That means winemakers aren't required to disclose exactly what is in each bottle; all they have to reveal is the alcohol content and whether the wine has sulfites or certain food coloring additives.
In Cork Dork, published by Penguin Books, Bosker immerses herself in the world of wine and interviews winemakers and scientists to distill for the average drinking person what goes into your bottle of pinot. "One of the things that I did was to go into this wine conglomerate [Treasury Wine Estates] that produces millions of bottles of wine per year," Bosker says. "People are there developing wine the way flavor scientists develop the new Oreo or Doritos flavor."
For Treasury Wine Estates, the process of developing a mass-market wine starts in a kind of “sensory insights lab," Bosker found. There, focus groups of professional tasters blind-sample a variety of Treasury’s wine products. The best ones are then sampled by average consumers to help winemakers get a sense of which “sensory profiles” would do best in stores and restaurants, whether it be “purplish wines with blackberry aromas, or low-alcohol wines in a pink shade," she writes.
From these baseline preferences, the winemakers take on the role of the scientist, adding a dash of acidity or a hint of red to bring their wines in line with what consumers want. Winemakers can draw on a list of more than 60 government-approved additives that can be used to tweak everything from color to acidity to even thickness.
Then the wines can be mass-produced in huge steel vats, which hold hundreds of gallons and are often infused with oak chips to impart the flavor of real oaken barrels. Every step of this fermentation process is closely monitored, and can be altered by changing temperature or adding more nutrients for the yeast. Eventually, the wine is packaged on huge assembly lines, churning out thousands of bottles an hour that will make their way to your grocery store aisle and can sometimes sell for essentially the same price as bottled water.
"This idea of massaging grapes with the help of science is not new," Bosker points out. The Romans, for example, added lead to their wine to make it thicker. In the Middle Ages, winemakers began adding sulfur to make wines stay fresh for longer.
However, starting in the 1970s, enologists (wine scientists) at the University of California at Davis took the science of winemaking to new heights, Bosker says. These entrepreneurial wine wizards pioneered new forms of fermentation to help prevent wine from spoiling and produce it more efficiently. Along with the wide range of additives, winemakers today can custom order yeast that will produce wine with certain flavors or characteristics. Someday soon, scientists might even build yeast from scratch.
Consumers most commonly associate these kinds of additives with cheap, mass-produced wines like Charles Shaw (aka "Two Buck Chuck") or Barefoot. But even the most expensive red wines often have their color boosted with the use of "mega-red" or "mega-purple" juice from other grape varieties, says Davis enologist Andrew Waterhouse. Other common manipulations include adding acidity with tartaric acid to compensate for the less acidic grapes grown in warmer climates, or adding sugar to compensate for the more acidic grapes grown in cooler climates.
Tannins, a substance found in grape skins, can be added to make a wine taste "drier" (less sweet) and polysaccharides can even be used to give the wine a "thicker mouthfeel," meaning the taste will linger more on the tongue.
When asked if there was any truth to the oft-repeated legend that cheap wine is bound to give more headaches and worse hangovers, Waterhouse was skeptical. "There's no particular reason that I can think of that expensive wine is better than cheap wine," Waterhouse says. He adds, however, that there isn't good data on the topic. "As you might suspect, the [National Institutes of Health] can't make wine headaches a high priority," he says.
Instead, Waterhouse suggests, there may be a simpler explanation: "It's just possible that people tend to drink more wine when it's cheap.”
While this widespread use of additives may make some natural-foods consumers cringe, Bosker found no safety or health issues to worry about in her research. Instead, she credits advancements in wine science with improving the experience of wine for most people by "democratizing quality." "The technological revolution that has taken place in the winery has actually elevated the quality of really low-end wines," Bosker says.
The main issue she has with the modern wine industry is that winemakers aren’t usually transparent with all of their ingredients—because they don’t have to be. "I find it outrageous that most people don't realize that their fancy Cabernet Sauvignon has actually been treated with all kinds of chemicals," Bosker says.
Yet behind those fancy labels and bottles and newfangled chemical manipulation, the biggest factor influencing the price of wine is an old one: terroir, or the qualities a wine draws from the region where it was grown. Famous winemaking areas such as Bordeaux, France, or Napa Valley, California, can still land prices 10 times higher than just as productive grape-growing land in other areas, says Waterhouse. Many of these winemakers grow varieties of grapes that produce less quantity, but are considered by winemakers to be far higher quality.
"Combine the low yield and the high cost of the land, and there's a real structural difference in the pricing of those wines," Waterhouse says. Yet as winemakers continue to advance the science of making, cultivating and bottling this endlessly desirable product, that may soon change. After all, as Bosker says, "wine and science have always gone hand in hand."
Ben Panko is a staff writer for Smithsonian.com