Issue link: http://winesandvines.uberflip.com/i/172581
winemaking make up for what maceration doesn't extract. Along the way he also touches on the Catch-22 of rampant skin avoidance: It's impossible. Machine harvesting guarantees some level of juice ooze on the way to the press; hand-harvested grapes piled atop each other in bins do the same, and even whole-cluster-pressed grapes mix skins and sauce during the press cycle. (Notice the color in cluster-pressed pink wines.) In fact, Wines & Vines hereby offers a cash prize (amount to be determined) to any winemaker who can extract the juice from 84 W in es & V i ne s OC TOB E R 20 13 a ton of grapes without incurring any skin contact. In other words, the right question about skin contact is not whether, but how much, and under what conditions and toward what stylistic end? Extraction roulette Jackson's next sentence is, "Like most choices in winemaking, each decision has its pros and cons." True enough: Intentional white skin maceration yields a more complex bundle of the good, the bad and the hard-to-tell than the simple strategy of avoidance. Chances are any skin soak will mine some combination of the following: Aromatic compounds: Fully formed aromatic compounds are scarce in grapes, with most of them requiring fermentation to develop. But the skins of certain grape varieties can be home to substantial concentrations of monoterpenes (linalool, geraniol) and grassy methoxypyrazines, things you might want (or not want) in your wines. Aromatic precursors: This is the bigger treasure trove for skin contacters. These include carotenoids (which can morph into rosy damascenone), cysteine conjugates (which lead to the thiols in Sauvignon Blanc) and glycoconjugates (sugar-bound potential volatiles). Just to keep things interesting, many of these compounds take their time in maturing, potentially creating an aromatic "bloom" well after fermentation is finished or even later in the bottle. Phenolics: Here we get from white skins flavonoid-type phenols, catechins and the like. Unlike the case of red skins, anthocyanins are not to be found, except in small concentrations in pinkish/gris grape varieties. (Color modification in skin-contact whites comes from carotenoids and other non-anthocyanin compounds.) Catechin monomers can produce bitterness, the factor that gives skin contact its bad reputation. More important, the absence of anthocyanins changes the normal rules for how tannins polymerize, how those polymers react with oxygen, how they precipitate and how astringent the tannins are—much less so in whites than reds. White skins also contain some amount of hydroxycinnamic esters (coutaric, caftaric and fertaric acids), which function as precursors for later volatile phenols. Elevated phenolic content may also help with the ageability of white wines made with skin contact. Nitrogen: Skins are the biggest repositories of nitrogen in grapes, and by extracting amino acids, skin contact increases the pool of available nutrients during yeast fermentation. Potassium: Skins are rich in this substance as well, and skin extraction can raise pH and lower acidity—a good reason not to try skin contact on already high-pH juice. Lipids: These fatty acids can be friend or foe, depending on their concentration and composition. The good news is that they become less prominent and less problematic as grapes approach full maturity. Microbes: As the Davis discussion notes, skins bring all manner of bugs into the mix—and not just earwigs or fruit flies. Since the general practice with skin contact