Explainer Science

What Does It Mean for a Wine To Be Alive?

A whole microbial ecosystem lives inside a bottle

David W. Brown By October 18, 2021
image of wine bottles in the shape of a butterfly
Illustration by Pete Ryan

When most drinkers describe a wine as being alive, they are speaking metaphorically, referring to the wine’s body and acidity. 

The descriptor can also be taken quite literally.

Life in a bottle

No, a bottle of Veuve Clicquot is not an animate creature like an otter or ocelot or Madame Clicquot herself, although wine is chemically active, and even ages and matures; compounds form and fail as acids and alcohols interact. But there are also living things swimming around in there. One study published from 2007 found that a wine’s microbial population can survive almost a hundred years after being bottled — and maybe longer.

“You can consider a bottle of wine as a microbial ecosystem where the pace of life has slowed down considerably to the world around it,” says Dr. Kevin Hand, an astrobiologist at NASA’s Jet Propulsion Laboratory. “It’s kind of nice when you think about how we like to drink wine and kind of slow down our own clocks.” 

When scientists look for life elsewhere, he explains, they look not for creatures, but for processes. Life is fundamentally a process called metabolism. “Eating, breathing, extruding various things that are extracted from and released into the environment. That can be gases, that can be minerals, that can be good old-fashioned waste,” he says. 

Yeast, bacteria, and fungi are ever present. When grapes are crushed, the newly exposed nutrients increase the diversity and activity of microbial life. “When the yeast is active and fermentation has gone gangbusters, obviously there’s a tremendous amount of life and biological activity occurring,” says Hand. Diversity decreases over time, but during malolactic fermentation — in which bacteria convert malic acid to lactic acid, softening the wine — crackling noises can even be heard inside the barrel. “Once sulfur dioxide is added, and other techniques applied, and once the wine is bottled, everything slows,” says Hand. The microbes in that bottle now live exclusively off the chemicals and minerals that reside in the bottle. 

That is one reason why cellaring a wine is so important, he says. “If you’re doing a good job of keeping your wine in a cellar, from a life and metabolism standpoint, you’re keeping temperature and pressure variables fixed. And the microbes that are in the bottle are initially having a great time, because there’s still a lot of interesting stuff in the bottle. But as they chew away on that stuff, the pH changes a little bit, the other conditions change, but the temperature and pressure stay the same.” Gradually, the viability of the microbes in the bottle decreases, and the metabolism slows down. “Essentially, the biology in the bottle flows to a standstill over decades. So it’s, it’s kind of cool, because in entropy and thermodynamics, we think about open and closed systems, and a wine bottle is very definitively a closed system.”

“You can consider a bottle of wine as a microbial ecosystem where the pace of life has slowed down considerably to the world around it. It’s kind of nice when you think about how we like to drink wine and kind of slow down our own clocks.”

The sacred link

The microbial world of wine has attracted intense interest with the ascendency of natural wines, which are generally unfiltered. The idea of literally living wines is part of the allure.

“Natural wines are literally more alive with microbial life,” says Holly Berrigan, the founder of MYSA Natural Wine. She says that, frequently, the liveliness of a glassful of microorganisms manifests in the mouthfeel of natural wines. She describes them broadly as being “slightly prickly on your tongue, not quite effervescent — though sometimes that too. More like a little dance on your tongue.” 

She continues, “This feeling is almost always more present in those wines versus those that use sulfur at bottling.”

The idea of living wine has also been considered mainstream for millennia — it was heretical to believe otherwise. 

As every ancient Roman and modern New Orleanian knows, Bacchus was the god of wine. In ancient Greece he was Dionysus. In both cases, wine was the embodiment of the cosmos itself — the inside and the outside, or culture and nature, civilization and wildness — not in opposition, but harmony. Wine facilitates the drinker’s transition from one to the other. 

One tenet of every Mass in Catholicism, celebrated by 1.2 billion people around the world, is transubstantiation: the literal transformation of wine into the living blood of Christ, consumed as part of the new and everlasting covenant. 

If, in the Catholic Mass, churchgoers who sip from the blessed chalice are drinking the living blood of Christ, natural wines are for people who want to drink the stable that he was born in. As Gary Baldwin, the director of Wine Network Consulting explains, if wine is not a living thing, it is certainly a thriving ecosystem.

“Wine is simply a culture of microorganisms,” he says. “And if it’s a natural wine, there could be a hundred different sorts of yeast cells in the bottle, and probably 50 types of bacterial cells.”

Depending on temperature and other conditions, certain organisms will continue to grow. “Bacteria will form a coat around themselves and seal themselves off, and they will sit there until the conditions are right to reproduce or to basically feed. Yeast are pretty smart organisms — they can do the same thing, sitting there for many years, just waiting for the conditions to be right,” he explains.

In a wine like pétillant naturel, pét-nat, yeast cells are deliberately left in the bottle to continue to produce carbon dioxide. “That is definitely a living wine. It has viable yeast and viable bacteria in it.” Baldwin says that once the yeast ferments all the viable sugar and nutrients, they will stop — but they are still there. “If you somehow put a teaspoon of sugar into that bottle again, they would keep fermenting.” Should a little bit of air make it through the wine’s seal, the bacteria will ultimately spoil the wine completely.

The downside

This can affect wines quite negatively — particularly in the case of the spoilage yeast Brettanomyces can sometimes gain a strong foothold. When bottled, the level of Brett present might be quite low, and present as inoffensive and perhaps pleasurable leather notes. “The sommelier at the restaurant that buys it doesn’t see it. But it’s not uncommon here for that wine to sit out for six months where it’s 22 degrees Celsius.” (71.6 degrees Fahrenheit). In those conditions, the Brett cells continuously pump out chemical compounds that turn those leather notes into a harsh barnyard smell. “After six months, the wine tastes awful. If the restaurant keeps the bottle for six years, it would also be volatile. It’s a living medium. Bacteria or yeast are happily doing their thing.”

Wine changes, matures over time. It is a vessel for life, as a biosphere, and for the religious, a symbol of eternal salvation. And the vibrancy and acidity of some wines lead drinkers to describe them as alive on the nose and palate. Ultimately, it seems, the question is not whether wine is living, but rather, from what perspective, and to what degree.