Photo Credit: Daniel Pambianchi
Winemaking is a devilish mistress. Once it gets into your blood you start to crave just that little bit more, and after a few — or a few dozen — kits many home winemakers wonder if that’s all there is or if they can up the thrill, increase the payoff and be like Oscar Goldman working on that crash-test cyborg to make them better, faster, stronger than before.
If you’re one of those winemakers, you’re in luck. In this kit column and in future issues we’ll be exploring expert techniques to increase the flavor impact, character, aroma and overall quality of your kit wine. The first technique, for white wines: aging sur lie.
What (is) sur lie?
Sur is the French word for “on” and lie is their spelling for lees, the sediment that settles to the bottom of the carboy during (and after) fermentation. In grape wines it consists of dormant and dead yeast cells as well as other grape solids including the skin and the seeds. In kit wines it’s almost exclusively formed from yeast, as the kits contain very low levels of grape solids compared to grapes. It was first observed by the Roman historian/logorrhoea-ist Cato, who noted that wines left on their lees developed different flavors from those in wines quickly separated from their sediment.
There are two items of primary importance when considering sur lie aging. First, it’s a technique for white wines only. The improvements it makes in white wines are mostly considered tragic and irredeemable flaws in reds.
Second, it’s a contrarian technique in many ways for whites as well. Whites made from grapes are often as heavily filtered as kits are prior to fermentation, and the racking schedule used keeps them from sustained contact with any yeast cells. The classical, standard French schedule for non sur lie wines is a first racking (called “débourbage,” roughly translated as “de-murking”) in November/December, the second in March (cellars are cold in France so this takes advantage of removing the tartrate drop-out accumulated over winter), a third in June (with sulfiting to halt any further activity) and another in September to lay the wine down for maturing in deep cellars.
There’s a third item that shouldn’t be overlooked in sur lie: care and cleanliness. One of the interesting quirks it presents is that it can vastly magnify flaws over time: improperly sanitized equipment, mildly stinky (reductive) fermentations or dull oak from tired barrels can suddenly spring to life like Godzilla from the deep blue sea and overwhelm otherwise good wine.
Why sur lies (and bâtonnage)?
Obviously the idea is to get something from the yeast cells into the wine. You’ll read a lot of fancy-pants terms in wine books about “hydrolytic enzymes” and “autolysis” but what they’re trying to say in laboratory language is that when the yeast cells settle out, they eventually die. In death, they do what all self-respecting organisms do: they rot. Their little cells putrefy and their guts spill out and get into the wine.
This process of rotting is what autolysis refers to, and the guts spilled have special properties. They include polysaccharides (long-chain sugars), amino acids, fatty acids and mannoproteins.
All of these compounds have their effects: polysaccharides give mouthfeel, a somewhat elusive term that conveys the perception of heaviness and weight (sometimes described as “creaminess” by more lyrical enthusiasts), and can also enhance fruitiness. Amino acids can boost flavor and aroma, particularly on the finish of the wine, and they play well with oak: not only do they sweeten up the raw woodiness of oak, they also modify some of the wood esters, mellowing them. Sur lie is sometimes practiced in barrels to take advantage of this.
Mannoproteins do a little dance with color compounds, which increases color stability, but that’s not a real issue for most whites, except over longer aging periods, when polymerized color compounds can drop out, leaving a deposit in the bottles — mannoproteins prevent that. Mannoproteins can also decrease astringency (puckery character) by binding to tannins, and there can be more of them in common whites than you might think. This binding can lead to a perception of increased sweetness.
In addition to these direct effects on the flavor and aroma of the wine, sur lie also has some secondary effects that we can take advantage of: it reduces oxidation of fruit aromas. It also acts like a fining agent, turning darker yellow wines lighter and more straw-colored, increases protein stability (unstable proteins show up sometimes as a deposit after aging, or as a haze that appears after a white wine is chilled) and prevents tartrate dropout. Note that the sur lies technique never travels alone. It’s always seen in the company of bâtonnage, which is the action of stirring the lees back into suspension in the wine.
Who sur lie (varietals)?
The classic candidate for sur lie aging in France is Melon de Bourgogne in the guise of Muscadet. Muscadet is a Loire wine and the name is a puzzlement: most French wines are named after the grape or the region they’re grown in. This one is named because it was said to have un goût musqué, musky or Muscat-like aromas. Strangely enough, it has only very low levels of any sort of flavor or aroma, making it ideal for this technique. As stated sur lie is a white wine technique. Reds, with greater levels of flavor and aroma get confused and stinky when aged sur lie, and for various good reasons are more subject to compromises of aging and fruit expression. The most aromatic, heavily flavored whites behave the same way, getting whiffy and weird. Light, crisp, neutral wines are the perfect starting canvas.
Interestingly, it’s not an age-old, time-honored technique in the Loire, having been widely practiced only in the last 100 years. Speculation is that Muscadet producers set aside barrels of wine for upcoming celebrations and discovered that after a year or so they had more flavor and texture, despite conventional wisdom which would have them stinky and oxidized. They started practicing it more regularly, added the lees stirring to get more out of it, and eventually threw in barrels to the mix, completing the sur lie process.
Another sur lie grape out there is Chardonnay, usually from the Burgundy region of France. Opinions vary widely (usually at one to three opinions per vineyard, of which there are thousands in Burgundy) but Chardonnay, contrary to popular perception is a low-character chameleon of the vineyard, taking on more from terroir and technique than genetic heritage for its flavor and aroma. Sur lie fattens it up, covers flaws and enhances and modifies oak notes.
Which wine kits should you choose? Chardonnay from cool-to-moderate climates is an excellent start. Very hot climate Chardonnay (Australia, California Central Valley) can be overly fruity and integrates poorly with sur lie. There aren’t that many Muscadet or melon kits out there these days, having fallen out of fashion, but Chardonnay’s distant cousins, Pinot Blanc and Gris (or Grigio) are fine candidates as well, especially from cooler climates in Washington state or France.
A leaner more sinewy style of Sauvignon Blanc works as well. The overwhelmingly popular New Zealand SB’s, with asparagus, grass clippings and the aroma of incontinent cats works less well as those flavors and aromas become magnified. France, and increasingly Chile, both provide good grapes for this. Chenin Blanc, whether from South Africa or California is also a good choice.
Kits to avoid would be anything from the Riesling family or similarly aromatic grapes such as Gewürztraminer, Viognier, Symphony et al. They’re already pushing the envelope for fruitiness and further enhancement can push them to strange and undrinkable places. Likewise super-ripe or hot climate derived kits will have overwhelming flavor development to begin with. Some of these are sold under fanciful proprietary names, but are easily recognized by high alcohol levels and wads of oak in the box.
How sur lie? (and should I cotton to bâtonnage?)
The actual execution of sur lie is deceptively easy. After the indicated time of primary fermentation on your kit, rack into your carboy, top up with a similar, finished wine to the bottom of the neck and wait. The topping up reduces the surface area exposed to oxygen exchange. This is necessary because carboys all leak air like sieves — the airlocks are blameless, as it’s the interface between the bung and the neck of the carboy that’s too porous to seal out oxygen transfer. By keeping the surface area of wine as small as possible you reduce the amount of oxygen pick up over the sur lie aging period.
The “deceptively easy” bit comes from how much tending and share of mind the wine will now need, for as long as you keep it on the lees, and how much you stir it. It’s one thing to say sur lie, and another thing to faithfully stir it once a week for a couple of years. Or twice a week, or once every two months, or perhaps not stirring it at all. Experience will be your guide in this, but as a rule of thumb good results can be had with more intense tending at the beginning and a little less as time passes. A previous schedule for sur lie on a Sonoma Chardonnay was as follows:
• Seven-day primary, rack to carboy and top up
• Stir twice per week for six weeks
• Add 25 PPM FSO2 (about one-quarter teaspoon of metabisulfite powder per six gallons, or about 1 gram per 23 liters. It’s helpful to get a sulfite test kit and measure this to double-check your addition)
• Stir once per week for eight weeks
• Stir once per month for one year
There are different opinions on schedules. Some people feel excessive stirring detrimental, others continue to stir weekly for a full two years. The subtleties are a bit beyond this discussion, but the timing above will keep the yeast in contact with the wine on a regular schedule and give it most of the benefits. Whatever the stirring schedule you adopt, do it gently and thoroughly — whipping the wine will oxidize it, but make sure you’ve got all the yeast back up off the bottom.
Sulfite, oak, stink and when to go to bottle
Too little sulfite and your sur lie wine will almost certainly oxidize. Too much and the SO2 will bind to too many compounds and reduce or flatten the aromas. Grape winemakers have to worry because their wines either need to complete or avoid malolactic fermentation. Wine kits don’t undergo MLF, but need the right amount of sulfite to keep them from oxidation or colonization by aerobic bacteria.
If your wine contains oak powder or chips in the fermentation or asks for them to be added post-fermentation, go ahead and use them on schedule. The sur lie process will modify them as described above and they won’t have a negative affect on the wine even if kept in contact for a year or two: most kit oak products give up 90% of their character in the first week of contact, and 100% within a month. A year or two extra won’t hurt.
One thing to be watchful for is the development of hydrogen sulphide (H2S), the smell of rotten eggs. If your yeast bed is deeper than one inch, or your kit uses yeast noted for producing H2S, smell the wine every time you stir it up. If you think you detect boiled eggs, wait a week, check it again and get a second opinion. If it’s still there and wasn’t transient, get the wine off of the lees and treat for hydrogen sulfide (sulfiting, aerating and possibly treatment with copper or other remedies). Next time, try again with another kit.
How do you know your sur lie process is complete? It’s over when you decide it’s over. But since the breakdown of the yeast takes six months (or longer) to complete at room temperature, you’ll be quitting before you finish if you pursue sur lie for much less than one year. Two years is probably pushing it: the returns diminish, and you risk oxidation or spoilage.
When you’re satisfied with the character of the wine, adjust the sulfite levels. Generally 25–30 PPM FSO2 is appropriate for most kit whites, but you may wish to consult your kit manufacturer for guidance. A very light fining will be necessary to polish the wine, and while I’m a positive proponent of filtration for wines, the choice is yours. When it’s perfectly clear, bottle it and allow it to rest for two or three months to calm down from the fining/filtering/bottling process. It won’t need any more bottle aging to show well, and indeed should probably be drunk up within a year or two at most, to show best.
The finished wine should demonstrate the bones of the varietal, along with a full, rich mouthfeel, an almost oily/creamy weight on the palate, along with a depth of fruit aromas, notes of cracker, biscuits or bread and increased richness on the finish.
Tim Vandergrift writes “Wine Kits” in every issue of WineMaker. Check out his blog at www.winemakermag.com/blogs/blogger/