Enartis

Anyone who believes fermentation is the only decisive moment in winemaking is… mistaken!

The post-fermentation phase is just as critical, perhaps even more so. It’s during this stage that wine begins to take shape, gaining structure, finesse, and its character is defined.

Let’s begin at the end of fermentation…

when yeast are exhausted (in every sense!) and undergo a process called autolysis.
Autolysis is the enzymatic breakdown of yeast cells, during which a variety of compounds are released into the wine: proteins, mannoproteins, amino acids, and more. When carefully managed, these elements can significantly enhance the final product, adding body and structure, stabilizing color, and offering protection against oxidation.

What Types of Lees Are Found After Fermentation?

After fermentation, not all lees are created equal. Understanding their composition and behavior is essential for guiding the wine toward quality and longevity.

Gross Lees
These consist of grape skin residues, seeds, possibly fining agents, and other heavy residues. Gross lees are microbiologically unstable and can lead to undesirable aromatic changes if left in contact with wine for too long. That’s why prompt racking is crucial immediately after fermentation.

Fine Lees
Fine lees are primarily made up of intact yeast cells or those undergoing autolysis. During autolysis, enzymes such as β-glucanases break down yeast cell walls, releasing beneficial compounds such as mannoproteins and glutathione.
Mannoproteins contribute to a smoother mouthfeel and enhance the perception of volume and softness.
Glutathione acts as a powerful antioxidant, helping preserve the wine’s aromatic integrity by preventing oxidation of its volatile compounds, ultimately supporting greater ageing potential.

Clearly, the compounds released during autolysis can offer significant benefits to wine, but only if the process is carefully managed under controlled conditions. When done right, this quiet phase can elevate the wine’s texture, stability, and aromatic finesse.

Lees management

In fresh, aromatic wines, prompt racking at the end of fermentation is essential to preserve sensory cleanliness. This ensures the wine rests only on fine lees, carefully selected for their quality.
At the same time, for structured reds or whites destined for ageing, extended contact with healthy fine lees can significantly enhance complexity, volume, and stability.

However, working with fermentation lees is a slow process, often misaligned with production timelines. Moreover, yeast cells may undergo stress during fermentation, compromising lees quality and releasing unwanted compounds such as acetic acid, volatile phenols, or biogenic amines, all of which can negatively impact wine aroma and taste.
A common issue is excessive reduction, caused by the activity of sulfite reductase, an enzyme naturally present in yeast. This catalyzes the formation of volatile sulfur compounds such as mercaptans, which, even at low concentrations, can severely impair a wine’s aromatic profile with unpleasant odors.
When lees shift from being a resource to a risk, posing sensory and microbiological instability, it becomes necessary to turn to controllable alternatives.

ImportanImportantly, when fermentation has been problematic, lees contact should be minimized or avoided altogether. To inhibit the metabolism and growth of spoilage microorganisms, EnartisStab MICRO M, a highly active chitosan-based antimicrobial, is recommended as a targeted treatment.

In winemaking, time and the pursuit of a specific sensory profile often become the final challenges to overcome. When traditional lees ageing is too slow or unpredictable, targeted technical solutions such as SURLÌ ELEVAGE and EnartisZym EZFILTER offer a precise and efficient alternative.

SURLÌ ELEVAGE is an inactivated yeast with an exceptionally high concentration of free mannoproteins. Unlike traditional lees, it releases its active compounds within just 24–48 hours, delivering rapid and reliable results. Wines treated with SURLÌ ELEVAGE show enhanced stability, aromatic complexity, and persistence on the nose. On the palate, mannoproteins contribute to a creamy texture, adding softness and roundness. A comparative analysis between control wine and wine treated with SURLÌ ELEVAGE, conducted five months after application, reveals a notable improvement in balance and overall aromatic complexity. This confirms the effectiveness of SURLÌ ELEVAGE in accelerating the release of beneficial compounds and enhancing the wine’s sensory profile in a shorter timeframe.

		To further optimize the extraction of desirable compounds during ageing on fine lees, EnartisZym EZFILTER offers a powerful complementary solution. Thanks to its high β-glucanase activity, EnartisZym EZFILTER acts directly on the cell walls, releasing polysaccharides. This contributes to: Improved smoothness and creaminess on the palate Enhanced aromatic persistence Improved colloidal stability for long-term wine quality When used after SURLÌ ELEVAGE addition, EnartisZym EZFILTER accelerates the release of valuable compounds from the lees, refining texture, aroma, and stability efficiently.

With careful management of fine lees and the support of targeted technical solutions, winemakers can transform this delicate phase into a powerful tool for improving stability, complexity, and longevity. Because it’s precisely there, beneath the surface, that wine truly takes shape.