By Tom Mansell, Science Editor
In our annual wines of the year tasting, the NYCR staff tasted many, many delicious wines. One of the big winners of the day was Paumanok Vineyards, whose wines swept the three Long Island categories in which they were nominated -- Merlot, White Wine and Ice/Dessert Wine).
Interestingly, all three of the winning wines (and a fourth wine that was also nominated in the white category) were bottled under screwcap closures. All of the submitted wines showed interesting and in some cases unique aromas and flavors, often bordering on exotic and tropical.
The NYCR tasting note on Paumanok's 2009 Sauvignon Blanc read:
The nose is extremely tropical -- typical of the sauvignon blanc musque clone -- with aromas of papaya, passion fruit, peach and mandarin orange with just a subtle grassy note beneath that fruit cocktail.
Similarly, when I tasted the 2009 Late Harvest Riesling during our wine of the year tasting, it showed a powerful tropical and stonefruit profile in addition to a spicy botrytis edge. It was so aromatically charged that a few of us (tasting blind) thought it could have been a muscat or gewürztraminer.
While I agree that clonal selection contributes to the tropical aromas, I would submit that the closure may also play a role.
Screwcap closures, specifically of the tin-lined variety, allow almost no oxygen to enter the wine after bottling. I don't want to get too much into the chemistry of sulfur in wine here (if you do, you can check out a piece I wrote not long ago for Palate Press). Briefly, there are many sulfur-containing compounds present in wine. Some are pleasant, including 3-mercaptohexanol (passion fruit/grapefuit) and 3-mercaptohexyl acetate (guava).
These compounds make up a large part of the varietal character of sauvignon blanc. Reductive conditions in the bottle (i.e., the absence of oxygen ingress) can help maintain these sulfur-containing compounds in an aromatically-active state.
Another important sulfur-containing compound found in wine is dimethyl sulfide, or DMS. At low concentrations, DMS can intensify berry aromas. From the NYCR tasting note for the winning Paumanok 2007 Tuthills Lane Vineyard Merlot:
Intense aromas of blueberry, black cherry and black plum fruit are accented by vanilla bean, sassafrass spice, violets and speck.
Bold, but well balanced on the palate, there are gobs of dark fruit here -- blueberry, plum, cherry and even a little fig -- with layers of cola and spice and vanilla and violets and cured/smoked meat. The spiciness leans toward the exotic, with sassafras coriander seed and sumac.
While I don't exactly know what "speck" is, I do know that DMS increases with bottle age and in some cases has been shown to increase more rapidly in bottles sealed in screwcaps. Again, it's possible that the closure could have played a role in the wine's aroma profile.
Before this piece comes off as a rousing endorsement of screwcaps, I should mention that these closures are not without their problems.
A typical complaint about bottles sealed under screwcap closures is what is broadly called "reduction", but more accurately known as "sulfur-like off aromas." These aromas range from a rotten egg-like smell (hydrogen sulfide) to cabbage and rubber (mercaptans) and garlic (sulfides). An excess of sulfides like DMS, for example, can lead to a canned corn and/or low tide aroma in wines.
This is not to imply that screwcaps "cause" reductive aromas. More precisely, the oxygen-poor environment that they create and maintain makes it easier to observe the sulfur-containing molecules that make their way into the bottle (for better or for worse... better for tropical aromas, worse for rotten eggs).
Luckily, the aroma of hydrogen sulfide in bottled wine is easily taken care of via aeration or decanting. The mercaptans and sulfides, however, are more persistent, and won't simply "blow off."
I recently opened a bottle of Paumanok's 2008 Chenin Blanc during a chenin tasting and found a bit of reduction on it that did not go away over the course of the evening. The 2009 Chenin Blanc showed well at the WoTY tasting with a nice peach iced tea note, but there may have been a reductive note creeping in there as well. Surely, radically changing a wine's exposure to oxygen has a bit of a learning curve.
Paumanok started bottling wines under screwcaps three years ago. Today, all of their whites and rosés, most of their dessert wines, and even some of the reds can be found under screwcap. I talked with Paumanok winemaker Kareem Massoud (pictured right surgically removing a broken cork from a 1993 local red) Long Island about the wines and the decision to use an alternative closure.
Massoud told me that part of the motivation for bottling aromatic whites and other wines with screwcap closures is simply avoiding cork as a closure. He cites Randall Grahm, saying that "any bottle of wine with a cork in it is corked." While this statement is likely to get you in trouble if you ever travel to Portugal, at the heart of the matter is the presence of haloanisoles like TCA (commonly referred to as "cork taint") in corks.
Most serious wine drinkers can tell when a wine shows the musty, stale aroma of cork taint (estimates of proportions of "corked" wines can range from 2% to 5%). However, Massoud seems more worried about when TCA's effects are more subtle. He astutely points out that even at levels below the detection threshold (which is remarkably low), TCA can suppress the perception of fruit. In other words, at low TCA levels, wine may not smell "corked", but rather display an absence of fruit... or just seem "off."
So in response to my question about the fruitiness of the wines in question, Massoud, one of the most technically savvy winemakers I have met in the industry, cites the lack of cork as a possible reason. He also stresses that meticulous viticultural practices (e.g., cluster thinning, leaf removal etc.) produce the best grapes and cleanest juice, leading to a ripe fruit profile.
Basically, working hard to bring in the ripest fruit possible goes a long way.
The "sulfur off-aroma"-causing molecules generally arise from an abundance of hydrogen sulfide (generated by yeast) during fermentation. "I'd be lying to you if I said I wasn't concerned about sulfides." says Massoud. He goes on to say that it's just good winemaking to manage sulfides during fermentation. The fewer sulfides that show up in the fermentation, the fewer will make it into the bottle. Active monitoring and management of fermentations in the cellar can mitigate the risk of these aromas.
Paumanok is also experimenting to observe the effects that screwcaps on the aging of their wines. Several bottlings (including Tuthills Lane Merlot) have been bottled under both screwcap and cork for comparison.
The library of screwcapped wines is shallow to date, but continued observation will guide decisions about future bottlings on screwcaps. For example, it seems too early to say how some of the reds will age under screwcap vs. cork, or which varieties are more suitable for screwcaps over the long term.
Interestingly, because of their radically different oxygen transmission rates, screwcapped wines are bottled with a smaller amount of sulfites than those sealed with cork. It will be intriguing to see how these wines compare in five to ten years or more.
The choice of closure is just one of a plethora of choices that growers and winemakers make from budbreak to bottling. As one of the most innovative wineries around, Paumanok is judiciously using alternative closures in an attempt to deliver the best wine that they can. And in most cases, especially the Sauvignon Blanc and Late Harvest Riesling, it's working out exceedingly well.
Segurel et al., Contribution of Dimethyl Sulfide to the Aroma of Syrah and Grenache Noir Wines and Estimation of Its Potential in Grapes of These Varieties, J. Ag. Food Chem., 2004
Brajkovich et al., Effect of Screwcap and Cork Closures on SO2 Levels and Aromas in a Sauvignon Blanc Wine, J. Ag. Food Chem., 2005
Brimstone in the Bottle: Sulfur Compounds in Wine