SHOWER POWER
When I open a bottle of Champagne, it often foams up all over the place, and I hate to waste that expensive stuff. What makes it behave that way?
T
he bottle had undoubtedly been treated roughly some time earlier, without having been given enough time to recover. It must rest quietly on ice or in the refrigerator for at least an hour before being gently removed and opened.In contemporary American society, Champagne is not meant to be drunk anyway. It is meant to be sprayed at Super Bowl winners in locker rooms.
The proper technique for these ebullient shenanigans, which I record here purely for its scientific and educational value (DO NOT TRY THIS AT HOME!), is first to pour out a little of the liquid to get more shaking space, then place a thumb over the bottle’s opening, shake the bottle vigorously, and quickly slide the thumb slightly backward—not sideways!—in order to aim a concentrated stream of frothing liquid precisely in the forward direction.
The scientific and educational point I want to make is this: The reason the liquid squirts out is not—repeat, not—because of any increased gas pressure within the bottle. You could fool any number of chemists and physicists on this point, but it’s true. The gas pressure does go up temporarily inside a shaken, sealed bottle, but that’s not what propels the liquid, because as soon as you pop the bottle open or slide back your thumb the pressure drops down to that of the air in the room. And anyway, how could gas pressure in the space above a liquid shoot the liquid out of the bottle? The powder charge in a bullet has to be behind the slug, doesn’t it?
Then why does the liquid shoot out with so much force when you release it immediately after shaking? The answer lies in the extremely rapid release of carbon dioxide gas from the liquid;
that’s what provides the shower power. It’s like an air gun that gets its power from the sudden release of trapped air. There is something about shaking the bottle that makes the gas want to escape almost instantly from the liquid. And in the mad rush to escape it carries a lot of liquid along with it.
Here’s why.
Carbon dioxide dissolves very easily in water, but once it’s there it is extremely reluctant to leave. For example, you can leave an open bottle of soda, beer, or Champagne on the table for several hours before it will go totally flat. One reason for this is that gas bubbles can’t just form spontaneously. The gas molecules need something to grab onto, some kind of an attractive gathering place where they can congregate in one spot until there are enough to form a bubble.
The gathering spots, called nucleation sites, might be microscopic specks of dust in the liquid or tiny imperfections in the container’s wall. If there are very few such nucleation sites available, the gas won’t form bubbles and will stay dissolved in the liquid. Beverage bottlers use highly filtered water for that reason.
But if many nucleation sites happen to be available, gas molecules will quickly gather around them and form baby bubbles. As more and more gas molecules gather, the bubbles grow, eventually becoming big enough to rise through the liquid and escape at the surface.
Shaking the bottle puts millions of tiny bubbles into the liquid from the gas space—the “head space”—above the liquid. These baby bubbles are extremely effective, ready-made nucleation sites upon which zillions of other gas molecules can quickly gather to form bigger and bigger bubbles. And the bigger the bubbles become, the more surface they offer for their fellow gas molecules to gather upon and the faster they grow. Thus, shaking the container immensely speeds up the release of gas, which occurs with such explosive force that a lot of liquid is swept along with it. Result: a very effective weapon for drench warfare.
Fluid fusillades aside, there are a couple of peacetime implications of these principles.
First, you don’t have to be afraid that jostling or shaking an unopened bottle or can of carbonated beverage will make it explode. Shaking it will indeed sweep out some gas from the liquid into the head space, but there just isn’t enough head space in the bottle to hold much
pressure. Besides, not long after a can or bottle has been shaken, all the baby-bubble nucleation sites will have risen back into the head space, where they can no longer do their dirty deed of, if you’ll pardon the expression, releasing gas. Just don’t open a container right after it has been shaken, while the nucleation bubbles are still distributed throughout the liquid. Let it rest first, to return to what chemists call “a state of equilibrium.”
The trick with Champagne and other sparkling beverages is to let them rest quietly for a couple of hours before opening them. What is so effective about fizzical combat is that you release the bottles’ contents immediately after shaking, while the bubbles are still down inside the liquid making their bubble trouble. But remember: Even though the Champagne is well rested, the Geneva Convention strictly forbids aiming a Champagne cork at anyone, civilian or combatant; it can do serious damage.
One last point: Because heat expels some of the gas from the liquid into the head space, a warm beverage will spritz more upon opening than a cold one will. That’s the other trick with Champagne; it must be cold. In fact, heat can cause so much gas pressure in the head space of a beverage container that an occasional can or bottle has burst in the trunk of a car parked in the hot sun.
SAVOIR FAIRE
What’s the best way to open a bottle of Champagne without looking like a bumbling idiot or hitting the ceiling with the cork?
T
he most important thing in opening a bottle of Champagne is to accomplish the task with such aplomb that it will appear to your guests as if you do it every day. This is very difficult to pull off while wincing at the expectation of imminent disaster. So conquer your fears by practicing a couple of times alone with some cheap sparkling wine as follows.First, remove the foil wrap covering the wire muzzle and the cork. To help you do that neatly without tearing all the foil away from the neck of the bottle, there is often a small tab to pull. (In my experience, either I can’t find it or it tears off when I pull it.)
With one hand, grasp the bottle firmly around its neck while pressing your thumb down on the top of the cork as insurance against the embarrassment of a premature evacuation. With your other hand, untwist the wire loop at the base of the muzzle and remove the wire. Now move your bottle-holding hand down to the bottle’s widest part and tilt it away from you at a 45º angle. (More about that later.) With your free hand, grip the cork firmly and twist the bottle—not the cork—until the cork begins to loosen, and then continue more slowly until the cork eases out. If you are faced with a recalcitrant cork that refuses to move, rock the cork with a forward-backward motion to loosen the stickiness between the glass and the cork.
Now, why did I say that you should twist the bottle, not the cork? Both Newton and Einstein agree that it shouldn’t matter at all which one you twist, because the motion is strictly relative. You could slice a loaf of bread by rubbing the loaf against the knife, couldn’t you? But think about it: In twisting out a cork, you must reposition your fingers several times, temporarily relinquishing your grip on it. During one of those times, it could pop out uncontrollably, depositing wine on the floor and egg on your face.
About tilting the bottle: You don’t want it to be vertical, of course, because you’d be in danger of shooting yourself in the face if the cork popped out. On the other hand, if the bottle is too close to horizontal the neck gets filled with liquid and the “head-space” gas floats up to form a bubble in the bottle’s shoulder. Then, when you release the pressure by removing the cork, the bubble expands suddenly, expelling the liquid in the neck. A 45º tilt will usually ensure that the head-space gas stays up in the neck, where it belongs.
Champagne for Dessert Champagne Jelly
C
hampagne can be eaten, not just drunk. The flavor and even some of the bubbles can be captured in this spectacular dessert. Created by California pastry chef Lindsey Shere, the sparkling and tender jelly literally melts in your mouth. Use an inexpensive Champagne or Prosecco, a sparkling Italian wine. Layer the jelly with berries or grapes for a parfait effect.(Eat your heart out, Jell-O.)
3¼ teaspoons unflavored gelatin (1 envelope plus part of a second) 1 cup cold water
¾ cup plus 3 tablespoons sugar 1 bottle dry Champagne (750 ml) 1 pint raspberries
1. Sprinkle the gelatin over the cold water in a medium saucepan and let soften, about 5 minutes.
2. Put the saucepan over low heat and stir with a spatula just until the gelatin has dissolved; do not overcook.
3. Reserve 1 tablespoon sugar. Stir in the remaining sugar and remove from the heat.
Stir until the sugar has thoroughly dissolved, then stir in the Champagne. Pour the gelatin into a shallow container, cover, and refrigerate until set, 8 or 10 hours.
4. At serving time, toss the raspberries with the remaining 1 tablespoon of sugar. With a fork, jumble the gelatin into small chunks.
5. Spoon a few tablespoons of Champagne Jelly into each of six parfait or stemmed glasses. Add a few berries and repeat layering until all of the jelly and berries are used, ending with berries. Refrigerate until ready to serve.
MAKES 6 SERVINGS
A REAL CORKER OF A PROBLEM
Some of the wines I buy have “corks” made of plastic. Is there a world cork shortage, or are there technical reasons for this?
I
asked the same question on a trip to Portugal and western Spain, where more than half of the world’s cork is grown, but I was unable to get a satisfactory answer. It was like asking a silkworm about polyester.Back home, I learned why many wineries are switching to plastic stoppers. Yes, they’re more economical than top-grade natural corks, but it’s as much about technology as economics.
We all learned in school that cork grows on trees called cork oaks. After picturing thousands of tree-ripened corks hanging from the branches, we were disappointed to learn that corks are actually cut from the bark of the tree.
Cork oaks are the very model of a renewable resource, because once the trees have reached maturity, which takes twenty-five years, the bark grows back time and again after being stripped. This is done by scoring circles around the trunk and large branches, slitting the bark lengthwise, and peeling it off in sheets, which are then boiled in water, stacked, and flattened. In the miles upon miles of cork oak groves that I saw in Portugal, each tree was marked in white paint with a big number, indicating the year in which its bark had last been stripped. It would be stripped again nine years from that date.
Looking at some freshly stripped bark, I was pleased to learn one thing that I had always wondered about: Is the bark really thick enough for the length of a wine cork? Yes, after nine years it is. The corks are punched out perpendicularly through the flattened sheets of bark like cutting tall, narrow cookies.
Throughout the hundreds of years that cork has been used to stopper wine bottles, there has
been a nagging problem. Known as cork taint or wine taint, it is a musty smell from a mold that afflicts a small percentage of corks and affects the taste of the wine. Quality control in modern wineries, especially in the large ones, has lowered the chances that your bottle will be “corked” or
“corky” to somewhere between 2 and 8 percent. Nevertheless, replacing the cork with a synthetic plastic is an attractive alternative, because mold won’t grow on plastic.
Here’s how the taint arises.
During the stripping, sorting, storage, and processing of the bark, there are many opportunities for molds to grow on it. The finished corks are usually treated with a chlorine solution to disinfect and bleach them. The chlorine doesn’t succeed in killing all the mold, however, and it has the side effect of producing chemicals called chlorophenols from natural phenolics in the cork. The surviving molds, plus others that join them during long ocean voyages from Portugal to California, for example, are able to convert some of these chlorophenols into a powerfully odoriferous chemical called 2,4,6-trichloroanisole, mercifully nicknamed TCA. It’s the TCA that makes wines taste and smell corky. It can be detected in concentrations of a few parts per trillion.
Plastic “corks” (synthetic closures, in the trade lingo) are now used to varying degrees by more than two hundred wineries worldwide. Companies such as Neocork and Nomacorc are turning out extruded polyethylene stoppers by the millions, while SupremeCorq makes its plastic stoppers by a molding process and takes the prize for creative spelling.
How do the synthetics compare with real corks? They seem to pass the tests for leakage, exclusion of oxygen, and printability—a requirement because many wineries use printing on the cork to carry marketing messages. But because the synthetic closures haven’t been around long enough for long-term aging studies, most wineries are using them for wines that are meant to be drunk young—within, say, six months of bottling, although Neocork says that its closures will hold up for as long as eighteen months.
But when connoisseurs pay more than a hundred dollars for a bottle of top-quality wine, they generally don’t want to see any new-fangled gimmicks. In an attempt to defuse any snobbishness, some wineries have been introducing plastic stoppers and even—would you believe?—screw-top closures on some of their believe?—screw-top-of-the-line products. After all, an aluminum cap is probably the ideal closure; it’s airtight, never gets moldy, and can be removed without any tools.
What next? Mouton-Rothschild in a box?
Some wine bottles these days have synthetic “corks,” which may be made of a rather tough plastic that gives you and your corkscrew a hard time. Check the point on your corkscrew to see if it’s really sharp. If not, sharpen it up with a file and it will penetrate even the toughest of “corks” with ease.
THE NOSE KNOWS
In a restaurant, when the waiter opens the wine and places the cork on the table, what am I supposed to do with it?
Y
ou’re not expected to sniff it for evidence of moldiness. That’s rare in this day and age.Moreover, when a small amount of the wine is poured for monsieur or madame’s approval, a couple of swirls and sniffs will tell all that one needs to know. If the wine smells and tastes fine, who cares what the cork smells like?
If you have an unquenchable urge to sniff something, sniff the glass before the wine is poured. If it smells like disinfectant or soap or anything else, for that matter—clean glass has no odor—ask for another glass, that is, unless you’ve ordered a bottle of plonk, in which case a little soap might be an improvement.
You might, however, glance casually at the cork to see if it is wet (and stained, if it’s a red wine) partway up. That means that the bottle has been properly stored on its side, with the cork
being constantly wet for a tight seal.
Historically, a restaurateur’s presentation of the cork to the patron was for an entirely different reason than sniffing for taint. It’s a practice that began in the nineteenth century when unscrupulous merchants developed the habit of passing off cheap wines as expensive ones.
Wine producers began to combat this practice by printing their names on the corks to prove authenticity. And, of course, the bottle was and still is always opened in the patron’s presence.
Today, rather than risk insulting a good restaurant by either sniffing the cork or putting on your reading glasses to scrutinize it, the best advice is just to ignore it. I like to fiddle with it during the breaks between courses, when in olden times I used to light a cigarette.
SAY WHEN!
I keep reading that moderate alcohol consumption can be a benefit to heart health. But what, exactly, is “moderate consumption”?
T
he usual evasive answer to this question is “one or two drinks a day.” But what is “a drink,”anyway? A bottle of beer? A glass of wine? A brimful, six-ounce martini? There are tall drinks and short drinks, stiff drinks and weak drinks. One man’s drink may look to the next guy like a thimbleful or a bucketful.
At home, if you’re in the habit of splashing scotch into your glass without measuring, the splash tends to grow bigger and bigger as the years go by. In a restaurant, how much alcohol is that bartender really giving you when he’s being either generous or stingy? In short, how much actual alcohol is there in “a drink?”
That’s the question that has been on everybody’s mind—well, mine, anyway—ever since the USDA came out with its latest “Dietary Guidelines for Americans” (fifth edition, 2000; it is revised every five years). I intend to answer that burning question right here and now.
But first, as they say on the radio, this message.
After warning that excessive drinking can lead to accidents, violence, suicide, high blood pressure, stroke, cancer, malnutrition, birth defects, and damage to the liver, pancreas, brain, and heart (whew!), the USDA guidelines state plainly that “drinking in moderation may lower risk for coronary heart disease, mainly among men over age forty-five and women over age fifty-five.”
(But hey, you college kids: It also states that “moderate consumption provides little, if any, health benefit for younger people.” In fact, it adds, “Risk of alcohol abuse increases when drinking starts at an early age.”)
At virtually the same time, a Harvard University epidemiological study published in the July 6, 2000, New England Journal of Medicine reported that after following 84,129 women from 1980 to 1994, those who drank moderately were found to have a 40 percent lower risk of cardiovascular disease than those who didn’t drink at all. For more than ten years now, similar
At virtually the same time, a Harvard University epidemiological study published in the July 6, 2000, New England Journal of Medicine reported that after following 84,129 women from 1980 to 1994, those who drank moderately were found to have a 40 percent lower risk of cardiovascular disease than those who didn’t drink at all. For more than ten years now, similar