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What Is Sur Lie Ageing?

What Is Sur Lie Ageing?

The best wines are aged wines and sur lie aged wines are no different. As the name implies, sur lie aging is the process of aging wine. However, it is different from other aging techniques.

Nevertheless, to understand sur lie aging, we must define what lees are in winemaking.

What Are Lees?

Lees are the deposit or residue of winemaking. In other words, lees are the byproduct of fermenting wine. 

Lees consist mainly of dead yeast. Although dead yeast sounds unappealing, they serve a purpose.

For example, lees absorb oxygen, preventing the wine from oxidizing. As the wine is aged, the lees will decay, emitting sugars and proteins in the wine.

The proteins then mix with the tannins to soften the mouthfeel and create a smoother texture. Additionally, lees balance the wine giving it some weight and texture.

What Is Sur Lie Ageing?

In contrast, sur lie aging is a technique winemakers use to allow lees to remain in the wine while it ages. Yes, it sounds strange, but sur lie aging adds complexity to wine if performed correctly. After all, a complex process will create a complex wine.

Most people assume the wine sits on top of a film of dead yeast. However, just because the yeast is dead does not mean no activity occurs.

As I mentioned above, yeast cells decay into sugars and proteins. These compounds react to the wine’s chemicals. In addition to this, flavor and aroma materials will be released during this time.

As proteins are released, they bond to wine tannins. Sur lie aging is beneficial to white wines since tannins are not preferred.

In contrast, tannins drastically impact red wines’ flavor and aging prospects. Therefore, sur lie aging may present a few problems regarding red wines, so they are not aged using this technique.

Furthermore, if a layer of lees is left uninterrupted at the base of the aging vessel, it will develop a foul sulfur flavor and aroma. To prevent this, winemakers battonage or stir the lees frequently.

Stirring sur lie aged wine prevents hydrogen sulfide from developing in the lees so quickly. In turn, this gives the wine the greatest exposure to the dead yeast and the proteins and sugars they break down into.

If you are sur lie aging wine at home, always pay attention to the flavor of the wine. It’s easy to forget about the wine and end up with unpleasant tastes and aromas.

If you taste a sulfur flavor or smell a sulfur aroma that’s reminiscent of rotten eggs, fine, rack, or filter the wine to remove the lees. 

Fining is probable the easiest method of removing lees. It involves adding a material that draws large pieces of residue together.

Winemakers often use bentonite clay produced from volcanic ash as a fining agent. The bentonite pulls large particles together, causing them to accumulate at the bottom of the aging vessel.

In contrast, racking a wine includes draining off most of the wine and leaving lees at the bottom of the aging barrel. Ideally, the racked wine will be smoother and clearer than the wine that was in the original aging vessel. Nevertheless, wines can be racked multiple times to remove sediment.

Filtering is just as it sounds. The wine is poured through a filter to sift out the larger pieces of sediment.

However, filtering can also pose a problem for the wine. Sometimes, the smaller particles that give the wine its complex profile can be filtered out, leaving you with subpar wine.

Make sure you remove the lees from the wine as soon as you get a whiff of sulfur. If you wait, the wine could be ruined entirely since you won’t be able to drink the wine.

How Long Does Sur Lie Take

If you ask a winemaker how long it takes to sur lie age wine, you probably get a different response from each winemaker you ask. Typically, wine is sur lie aged for 9-10 months.

Winemakers stop stirring once the wines complete malolactic fermentation. Malolactic fermentation is a process that softens wines and gives them a complex and rounder aroma and flavor.

Final Thoughts

Sur lie aging is a technique that gives the wine some serious flavor. Nothing compares to the complex flavor that sur lie aging creates.

Although it sounds strange to let wine hang out with dead yeast cells, trust me when I say don’t knock sur lie aged wine until you try it. You will be pleasantly surprised when you inhale the aroma and sip on the beauty of this aged wined.