Winemaking Articles and Info > Wine Article: Gimme Some Skin (Time)

Gimme Some Skin Time - Extended Maceration Winemaking
by Byron Burch

Every year, during the late summer, home winemakers can be observed exuding a certain nervous energy as they wait to see what nature has in store for them during that year's crush. Having made wine for more than 30 years now, I've done my share of anticipating, and one thing I've learned is that, if someone is paying attention, there aren't that many things that can go wrong, but each year's wine is going to have its own nuances.

Quite a few years ago, the conditions were just right for something to happen that I'd wondered about for some time.

I was making Cabernet Sauvignon from a good vineyard, and my custom was to let most red wines ferment all the way dry on the skins. Normally, that took about a week to ten days. I'd heard, however, that some French wines were kept on the skins for as long as three weeks, though, at the time, I'd not seen any information on how that might be encouraged.

I fermented my wine in an unheated outbuilding. That year had been a relatively late season, but the fruit was in excellent condition at harvest. My must got warm enough, early in the process, to extract good color. Then came a really cold spell that slowed the fermentation to almost nothing.

Morning and evening, I went out to punch down the cap, and each time it had risen back up. Gas was still being released. The fermentation process was still going on. It ended up taking nearly three full weeks. Finally, the cap no longer rose to the top, and it was time to press.

That was a long time ago, but I still think of that wine with great fondness. It may have been the best I've ever made. There was fruit, balance, complexity, and most noticably, a smoothness and subtlety I'd not been finding in my reds up to that time. Like many California winemakers in those days, I'd been going for big, rough, tannic monsters. That's what we thought most red wines should be. A lot has changed. While we recognize that such wines have their place, there are other possibilities, and adjusting the skin time either upward or downward will have much to do with the kind of wine we extract from a given lot of grapes.

In Knowing and Making Wine, Emile Peynaud observes that, "Pomace contact exercises an influence on body, on the greater or less astringent taste, on the evolution and life of the wine, and the ease with which malolactic fermentation takes place." A winemaker must remain flexible, deciding what to do according to "the quality of the grapes and the type of wine being made. . . ."

Nowadays, we hear a lot more people talk about "extended maceration" (long skin contact) than we did just a few years ago. This approach has now become widely recognized as a sophisticated "third way" of approaching red wine fermentation. The first two ways are already familiar to many home winemakers.

In the first method, the must goes through just enough skin contact to establish good color (usually three or four days of active fermentation) and pressing then takes place with some sugar (3-5 Brix or so) remaining in the juice. This method is often used for table wines expected to be consumed young. Some first time home winemakers press early in order to have wine to enjoy as soon as possible. This is also a good technique for certain grape varieties (such as Gamay type grapes, or perhaps Merlot) especially suited for that purpose.

Another reason for pressing early might be the presence of moldy grapes. In this case, sulfite to 120-130 parts per million, letting the must stand for at six hours before adding yeast. Press after three days of active fermentation.

The second method is more commonly used. The must is simply allowed to ferment all the way dry, and pressed as soon as the "cap" fails to rise after punching down, leaving wine visible on the surface after several hours. Referring to the removal of free-run juice as "draining," Peynaud calls this method "draining hot." The skins, of course, are pressed.

The third method, "extended maceration," can take one of three forms. The first, the one used with the Cabernet Sauvignon mentioned earlier, might be viewed as simply a variant on method two, fermenting dry on the skins. The only difference is in utilizing cold weather, as I did, or perhaps air-conditioning, to extend the fermentation much longer than it would otherwise go.

The second form of extended maceration involves using a combination of temperature control, along with the direct application of a carbon dioxide atmosphere to the surface of the wine
and skins. After the end of active fermentation, chill down the fermentor and store it for several days, blanketed with CO2. Home winemakers should add CO2 at least twice a day, or hold the must in a pressure vessel, and control conditions as carefully as possible until there has been a total of three weeks of skin contact after the grapes were crushed. The wine is then "drained cold," and pressed. This method may be used for many of the popular varietals: Cabernet Sauvignon, Merlot, Zinfandel, Shiraz, etc.

Pinot Noir, however, is best treated with a cold soak that takes place prior to fermentation. In this case, the grapes should be picked, crushed, and maintained under as cool conditions as possible. Again, cold storage, along with the application of carbon dioxide, are used, this time to inhibit the onset of fermentation for five days or so.

In the fall of last year, Nancy Vineyard used a cold soak before fermentation to make what is developing into a superb Pinot Noir. Lacking adequate refrigeration capacity, she tried to kill two birds with one stone. Dry ice was used to implement the cold soak, providing both the cold and the carbon dioxide.

It worked magnificently, though she wandered around the shop for several days during the process muttering, "Those were really good grapes, and I hope I haven't totally blown it." Nancy warns that the use of dry ice is not a technique for the faint of heart. It turns the skins a rather ugly, brownish color, so ugly, in fact, that thinking you've blown it quite badly is a very realistic fear. However, her wine now has excellent color (not always easy with Pinot Noir) and shows remarkable promise. Using carbon dioxide and refrigeration, rather than dry ice, may help avoid some tense moments.

Note

The cold soak treatment involved placing about 5 lbs. of Dry Ice Pellets into each of two large square 28 gallon plastic primaries with the crushed must. So2 was added to 35-40 ppm. The temperature was maintained with the pellets below 55 °F. until it naturally rose to 70 °F, after about 3 days. Yeast food and yeast was added and the fermentation proceeded normally, lasting about 10 days. Dry Ice pellets can be purchased by the pound from several local Compressed Gas companies that sell CO2 in cylinders. Take a picnic cooler to hold the pellets.

A few years ago, a friend from the wine industry (Sorry, I've forgotten who) explained to us that extended maceration, whatever the method, allows the completion of a "tannin cycle." The presence of skins, seeds, and stems during fermentation contribute tannin to the wine. Tannin is the dry, puckery astringency that sticks your tongue to the roof of your mouth when you taste some red wines, especially young ones.

Up to a point, tannin becomes more and more assertive, and can give red wines a harshness that can't be easily overcome, though fining with gelatin will cause some tannin to be absorbed and dropped out.

If, however, the maceration is extended, in one of the ways I've suggested, something unexpected begins to happen. Instead of causing more harshness, as might be expected, the
tannin reaction is allowed to go full circle. It begins to smooth out, contributing a balanced complexity to the wine.

Anyway, no matter how improbable the theory sounds, we've tried extended maceration a couple of different ways, with good results if a smooth wine is to your liking. So, if you've got the facilities, and the guts, and grapes that are in really good condition, you might find one of these techniques an interesting experiment this fall.

Consider setting aside a hundred pounds or so of your grapes as a small test batch for comparative purposes.

After all, you get to open the topic of conversation with, "I've had about a week of skin contact...."

 

 

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