gettin' jiggly with it

One of my favorite scenes in the film My Best Friend's Wedding is the heart-to-heart conversation between bride-to-be Kimmi (Cameron Diaz) and Julia Roberts' would-be groom stealer, right after the groom has called off the wedding because of a misunderstanding (orchestrated, it must be noted, by a now-repentant Roberts). Attempting to explain why the groom would change his mind so suddenly, Roberts' character -- a food critic by trade -- draws a culinary analogy between creme brulee and that All-American staple, Jell-O. A diner in a fine restaurant might be enamored with the sweet, elegant perfection of creme brulee, she maintains, but could then suddenly realize that what he really wants is... Jell-O. Why? "Because he's comfortable with Jell-O," she says. "I can be Jell-O," Kimmi tearfully offers, to which Roberts replies, "No, you can't. Creme brulee can never be Jell-O."

I'll spare you my usual exasperated rant over Kimmi's insistent follow-up -- "But I have to be Jell-O!" -- with all its implications for the character's sad lack of self-esteem. That's another post altogether. (I am much more compassionate than Jen-Luc Piquant, who simply loathes the pernicious breed of female that literally can't seem to stand up without a man's arm to lean on.) Roberts' food critic has a point: creme brulee can never be Jell-O, even though both depend on cross-linking proteins for their jiggly consistency. With creme brulee, proteins in the eggs and milk form stronger bonds in response to heat, changing its consistency from a liquid to a semi-solid. The opposite occurs with Jell-O: the proteins form stronger bonds as they cool. So it's true: creme brulee can never be Jell-O.

The components of Jell-O are gloriously simple: nothing but gelatin, water and sugar, plus any artificial flavors and colorings that are added to bolster the fun factor. But where does the gelatin come from? You might be sorry you asked. Gelatin is a processed protein called collagen, derived from the bones, hooves and connective tissues of cows or pigs. Those parts are ground up and mixed with acid or other chemicals to break down the cellular structure, thereby releasing the collagen. Boiling the whole mess causes a layer of gelatin to form on the top, which can be skimmed off for further processing. Eventually it ends up in your local grocery store aisle in powder form.

Different proteins have different structures, and this gives them different properties, which in turn determines whether they solidify into gelatin or creme brulee (or a yummy flan, for that matter). Gelatin 's structure is similar to DNA, except where DNA has two chains twisted together into a spiral, the proteins that make up gelatin have three chains of amino acids tightly bonded together. The only thing that breaks those bonds is energy. A lot of energy. That's where the boiling water comes in: it adds a great deal of energy, in the form of heat, sufficient to cause the three strands of amino acids in collagen to unwind. Adding cold water, and then putting the Jell-O into the refrigerator to cool, causes the chains to start bonding again.

Because it takes so long to cool, the amino acid chains become entangled (when stirred) and water gets into gaps between the chains. That's why Jell-O wriggles so appealingly. It's also why the "short-cut" method of adding ice so the gelatin will set more quickly, is never quite as firm as the Jell-O produced by the slow-set method. The various molecules cool so quickly that they can't self-organize in the most efficient and strongest bonds possible; instead, only a loose matrix forms. If the energy levels of the requisite molecules are lowered more gradually, as in the slow-setting method, they have more time to align properly, forming a much denser lattice structure, trapping the mixture of sugar, pigments and water in between the strands of amino acids. Behold, the secret behind the Jell-O mold! It all comes down to thermodynamics.

Jell-O's unique consistency -- hovering somewhere between solid and liquid -- and its mold-ability make it an intriguing potential medium for, say, artists. Anyone who happens to be in the Bay Area today (April 1) should swing by the San Francisco Exploratorium, which is marking the 100th anniversary of the great 1906 earthquake that laid waste to that great city with a special one-day art installation by local artist Liz Hickok. She crafted a scale model of the entire city out of multi-colored Jell-O: everything from City Hall to the Golden Gate Bridge. And no, this isn't an April Fool's Day prank; I offer an actual photo as proof (there are more on Hickok's Website). Hickok relied on satellite images to design scaled-down molds, which she used to cast the buildings in various flavors of Jell-O. Considering the degree of stability required to do so, I'm guessing she didn't cheat, and opted for the slow-set method.

The entire jiggling array was mounted on a slab of plexiglass and then placed on a vibrating table to demonstrate to the gathered museum visitors exactly how those violent earthquake tremors can affect buildings. Specifically, it demonstrates something called "liquefaction," which is what happens when the earthquake pressurizes the water in soil underneath a building. Liquefaction is responsible for much of the structural devastation wrought by earthquakes.

Hickok's installation is pretty elaborate. She also paints backdrops and incorporates models of mountains and trees, and even incorporates special lighting to illuminate her scenes from the back, or from below. The Jell-O buildings in Hickok's San Francisco sculpture aren't permanent, which is why the exhibit only lasts a day: the gelatin quickly decays, leaving behind the photographs and video elements as the exhibit's only lasting artifacts.

Hickok has likened her backdrop approach to constructing a movie set. At least one Hollywood blockbuster film required special CGI effects that mimicked the properties of a gelatinous substance: Walt Disney's Flubber. Robin Williams co-starred with a jiggling green blob -- the Flubber -- that had a consistency based in part on a type of hair gel, according to animation director Tom Bertino, who never did identify the brand publicly. To get the right degree of elasticity, Bertino's team used a computer modeling program called Metaclay, normally used to simulate liquid effects, to mold and shape the green blob frame by frame, much like old-fashioned hand-drawn animation.

The unusual properties of gelatinous substances could even lead to revolutionary new treatments for spinal cord injuries, according to a recent article in Wired. Scientists have found that adding stem cells -- which can cure rats of spinal cord injuries, if not humans -- to spinal implants made of hydrogels can help patients with old injuries regain a certain degree of function. The gels are basically polymers whose properties are very similar to those of Jell-O, resembling the soft tissue that surrounds the human spinal cord as it develops in the womb. The hydrogel fills the spaces in the injured areas, creating a kind of scaffolding that new cells can grow around, building a bridge of sorts to repair the damage. It's only been demonstrated in rats so far, and scaling the technique up for use in human beings is a daunting challenge, but the researchers expect human trials to begin in the next five years or so.

We conclude our (mostly) frivolous weekend digression into the wonders of Jell-O with a a link to a decidedly over-21 sort of science project. The budding experimentalist in question set out to determine the highest possible concentration of alcohol (using 80% proof vodka) a given Jell-O shot could contain while still maintaining "structural integrity" -- a fancy way of saying its ability to gel satisfactorily. You might recall from past science classes that alcohol has a lower freezing point than just plain water. That's why legend has it that the cook aboard the doomed Titanic managed to survive being plunged into icy ocean waters: he'd been drinking heavily, and all that extra blood in his alcohol kept him from freezing to death before he could be rescued. So it stands to reason that adding more and more alcohol to Jell-O shots would make it harder and harder for the substance to gel.

Jen-Luc Piquant prefers less plebeian imbibements, but I've downed a few Jell-O shots in my day, and frankly, how well it gelled wasn't anyone's top priority. But that's no reason not to replicate the experiment, nosiree. After all, reproducibility is the pinnacle of the scientific method, provided one is of legal drinking age and does so responsibly. So in the interest of scientific progress, stock up on a little Jell-O and Smirnoff's this weekend. Happy gellin'!

 

Comments

[Blake Stacey]

It is widely reported that Tom Lehrer invented the Jell-O shot. In fact, though he may not have been the first to hit upon such an elegant and simple idea, he and a friend struck upon the concept while Lehrer was in the Army, during the 1950s. While serving on a Navy base (as an "Army liason to the Office of Navel Contemplation"), Lehrer attended a Christmas party whose official rules forbade alcoholic beverages. Technically speaking, Jell-O wasn't a beverage.

"And we finally decided that orange Jell-O and vodka was the best. We tried gin and vodka and various flavors and stuff -- of course you can't sample too much. So we went over to her apartment and we made all these little cups and we thought I would bring them in, hoping that the Marine guard would say, 'OK, what's in there?' And we'd say, 'Jell-O.' and then he'd say, 'Oh, OK.' But no, he didn't even ask. So it worked. I recommend it. Orange Jell-O."

There's a great Larry Gonick cartoon in an old Discover Magazine about getting the water out of seaweed Jell-O to make aerogel. The secret? Flush out the water with CO2, then freeze it and drop the pressure so that the CO2 sublimes directly from a solid to a gas. Or you can raise the pressure above the critical point, so that the fluid filler goes from liquid to gas without a sharp phase transition. Yay thermodynamics!

http://www.sfweekly.com/issues/2000-04-19/feature_2.html (Tom Lehrer interview)

http://en.wikipedia.org/wiki/Critical_point_%28thermodynamics%29 (thermodynamics)

[JenLucPiquant]

Thanks for providing that fantastic Lehrer anecdote. Who knew? (Well, Blake Stacey, apparently...) Also for the news that there is such a thing as seaweed Jell-O. Personally I prefer the lime... :)

[Lee Kottner]

One of the defining moments in my undergrad college career occured the night I was sterilizing Agar-Agar (http://en.wikipedia.org/wiki/Agar) for the bio lab and realized the Twinkie I was eating contained the same vile-smelling jiggly stuff as a binder. Like Jell-O, agar gels as it cools, but after smelling it fresh out of the autoclave, I never knew anyone but bacteria could mistake it for food. It made me look at processed food in a whole new way. Not to mention putting me off Jell-O for good--no mean feat for a Midwestern girl raised on Jell-O salads.

P.S. DNA comes in a helix, not a spiral. The latter curl in on themselves (so that spiral notebook you've got is really a helix notebook).

[Blake Stacey]

Yay! I serve a purpose!

I just noticed that the Wikipedia article for "Petri dish" says they are used for various "day-to-day laboratory practices", including agar plates. Oddly, it says nothing about the feasibility of dish-shaped Orange Jell-O shots made with laboratory-grade pure ethanol. I suppose nobody ever said the Wikipedia was comprehensive, but golly, how do they get away with this sort of omission? Didn't the people at Nature check this kind of thing?

Ah, laboratory-grade pure ethanol. . . just thinking about that takes me back. Truly manly men don't mind the trace quantities of benzene left over from the purification process (which is probably why all the truly manly men are hanging out in the oncology wards these days). As an undergrad, I knew an organic chemist who kept a jug of pure ethanol around, mostly for shock value -- it was the anhydrous caffeine which really got used. Ever seen anhydrous caffeine? He had a hundred-gram bottle of this white powder which tasted bitter as hell and looked like anthrax. His idea for caffeinated orange juice was a big success; we probably could have opened a franchise in the student center. I also heard tales that he nearly set his room on fire trying to extract the thujone from absinthe, but I wasn't there to see that. . . .