Why vintners are turning to lees
Winemakers are rethinking dead yeast cells – called lees – not as waste, but as a vital tool for flavour, stability and sustainability. From reducing sulfites to improving texture, lees are reshaping how both still and sparkling wines are made. Kathleen Willcox reports.
Wine is romance, and dead yeast cells are anything but. After working hard to convert sugar into alcohol, the yeast expires and settles at the bottom of a fermentation vessel. While most consumers can and probably should just leave it at that, vintners’ relationship with these dead cells, aka lees, often has an outsize effect on what you taste in your glass.
Wine lees are an offshoot of the fermentation process, consisting of dead yeast cells, with bits of grape skins, tartrates and other residual solids that settle during fermentation and ageing thrown in for good measure. What is known as “gross lees” are the heavier and more obvious sediments that are removed quickly, whereas “fine lees” are smaller bits that are allowed to remain.
And while they are a byproduct of winemaking, they are also a quiet ingredient shaping a wine’s flavour, texture and body. Increasingly, lees’ role as a quiet member of the supporting cast has been upgraded as vintners develop an ever-deeper understanding of just how much lees can contribute to both still and sparkling wines.
Creating a reductive style
Reductive wines — the flinty, struck match version, as opposed to the rotten egg iteration — have been increasingly popular among wine enthusiasts and makers after a long era of increasingly exuberant and abundant wines began to feel extra.
Lees are becoming an increasingly essential component for vintners creating this style of wine.
“We use lees to create a reductive style of wine,” says Dieter Cronje, winemaker at Presqu’ile in Santa Maria, CA. “We achieve this by using fine lees to absorb oxygen, which then typically allows you to also reduce sulfite use.”
McPrice Myers, founder and winemaker at Paso Robles’ McPrice Myers Wines, concurs, saying that lees help “ensure the longevity of the wines we craft far beyond their time in barrel.”
And because lees are a natural anti-oxidant and protectant, the winemaking team can deploy less sulphur during the wine’s elevages.
Increasing ageability and reducing sulfites
Sulfites occur naturally in wine, and they are also added to prevent oxidation and spoilage, thereby preserving its flavour and aroma. The widespread use of sulfites only became widespread in the 20th century, and in 1986, the FDA mandated that wines containing more than 10 ppm include a “Contains Sulfites” label.
Too many sulfites can mask a wine’s natural aromas, even causing it to smell like rotting cabbage. It can also lend a harsh metallic tang to the wine. Plus, sulfites have received a bad rap in recent years, having been linked to headaches. (In reality, only 1% of the population is allergic to sulfites, which are also present in deli meat, French fries and sodas).
The ominous out-of-context label reference and the reality that too many sulfites can make wine smell like hot garbage have made sulfite reduction an increasingly central goal for many vintners. (It’s also worth noting that sulphites are the only ingredient of the dozens of arguably much more potentially grotesque options like isinglass or dried fish bladders and defoaming agents that winemakers are legally allowed to add to their wines that they must alert the public to.)
While some large-scale industrial wineries will likely always rely on using sulfites at multiple stages of the winemaking process, others are finding that relying on lees more allows them to reduce or eliminate the practice.
For Emanuele Reolon, the estate director at Isole e Olena in Chianti, relying on lees for their preservative effects has helped him reduce sulfite levels by about 50%.
“For our Chardonnay, we age on lees for nine months after fermentation, and this helps us in any number of ways,” says Reolon. “It creates a much more complete flavour, of course, but on a chemical level, it reduces the level of oxidation in the wine because lees attracts oxygen. We discovered that we could eliminate the step of adding sulfites at this stage by relying on lees.”
Relying on lees to boost acidity, reflecting terroir
For many producers, lees is a one-stop shop that allows them to boost brightness, reflect terroir and sometimes completely eliminate the use of sulfites.
Sebastián Zuccardi, winemaker and a member of the third generation at Mendoza’s Bodega Zuccardi Valle de Uco, also avoids adding sulfites during pressing or when alcoholic fermentation is over because he wants to avoid malolactic fermentation and hang onto every scrap of natural acidity available. Eliminating sulfite interventions done “solely as a precaution,” because he’s found that they can suppress flavour expression, he utilises them only when necessary, by observing strict cleanliness around the winery and managing oxygen with lees.
“We always try to work with a significant amount of lees during both fermentation and ageing, and this becomes more evident in white wines,” Zuccardi says. “They capture oxygen and prevent oxidation, and while they don’t completely replace sulfur dioxide, they can help reduce its levels, or even allow us to avoid using it altogether.”
For producers like Stefano Casadei, owner and technical director at Famiglia Casadei, who worry that the use of sulfur dioxide clouds terroir, lees have become pinch hits for underlining a wine’s sense of place.
“The decision to gradually reduce the use of sulfur dioxide stems from a desire to make our agricultural approach increasingly aligned with a sustainable, regenerative and minimally interventionist philosophy,” Casadei says. “Working with lees has proven valuable not only in limiting the use of sulfur. The polysaccharides released during ageing on lees contribute elegantly to the wine’s stability and structure.”
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Casadei explains that, when combined with batonnage, the technique adds complexity and texture, as well as contributing to a more stable environment.
His approach to lees in lieu of sulfites allowed him to launch an estate line of wines made with no added sulfites. The line, dubbed Mi Piace, is distributed by Total Wine and has been a runaway success.
Adding cream to whites, toning down tannins in reds
Lees are also becoming, for many, the best way to showcase a wine’s truest and best nature.
At Alta Colina, the team stirs the barrels to maximise and enhance lees contact with wine.
“Polysaccharides and mannoproteins from cell walls dissolve into the wine and are permanently present,” owner & director of winemaking at Alta Colina, Bob Tillman. “Everything else falls back to the bottom of the barrel and is removed when we rack the wine. At first, you might think this would add sweetness to the wine, but it is not perceived as sweet. Instead, in whites it affects the mid-palate, yielding wines that are more creamy, rounder, and with softened acids.”
For reds, Tillman says lees provides all of the same benefits, with the added bonus of toning down perceived tannins.
While Dan Petroski only makes whites at Massican Wine, he depends on gross and fine lees to minimise sulfur additions, following the Raw Wine Fair as a guide and aiming for 60 ppm.
“Because I make white wines only and bottle them soon after fermentation, within six months, I age on lees,” he says. “I don’t rack the wines post-fermentation until I’m ready to bottle, so they remain on their gross lees and maintain a fair amount of CO2 from fermentation. Knowing that, I manage my sulfur based on the acid levels of my wines when considering how much I’ll need for elevage and bottling.”
Christopher Christensen, winemaker and owner of California’s Bodkin Wines, says he finds that relying on completely unstirred lees has allowed him to nail the flavour profile he’s going for, without relying on excess sulfur dioxide additions as a crutch.
“The lower the pH of a wine, the longer lasting it will be with minimal sulfite additions,” Christensen says. “The less you do with a wine, the greater the rewards, but then you have to really think about the chemistry. I want high-acid wines, but I don’t want them to taste that way because then it will be like drinking lemonade without sugar.”
He uses lees ageing to subtly and slowly break down the searing nature of the high-acid wines.
“I first realised that lees ageing could make really high-acid wines taste rounder and fuller, and give the perception of sweetness when I was working with sparkling wines,” Christensen says.
Lees mimic the role of dosage in sparkling wine
Producers at sparkling houses chasing the “zero dosage” trend have found that long lees ageing mimics the texture, vibrance and flavours that dosage traditionally delivers.
Dosage, or mixture of wine and sugary syrup traditionally added to Champagne, rounded out the flavours of an often edgy wine grown in the margins of climatic viability. But changing tastes, a desire for zero sugar everything and climate change have all contributed to the increased popularity of naked Champagne.
Scott Caraccioli, general manager of Caraccioli Cellars in the Santa Lucia Highlands, says that “over time, the acid structure will become less pronounced over time if that sparkling wine ages on lees. It’s why my limited-run no-dosage Natures are released after so many years. My current vintage is 2013. The brioche character is advanced with the extra time and becomes more showy with the ageing fruit.”
Dosage, he argues, generally becomes the “amp to the speaker of the fruit. With no dosage released, young its flavour is close to acid water. It’s hollow. There’s nothing mid-palate. You’ve got to give the lees time to sink in.”
Cédric Jacopin, cellar master at Champagne de Saint-Gall, agrees that proteins and polysaccharides from the lees contribute to a sensation of sweetness in Champagne, even without dosage.
“Our Zero Dosage wines spent over 20 years ageing on lees before disgorgement,” he explains. “We can lower the dosage to preserve freshness and maintain balance.”
Dead yeast cells may not inspire poetry, but without them, wine would be far from fine.
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