if only elevators had cocktail bars

[by john]

i've really been digging some books on public speaking lately (both via naveen) - presentation zen design and confessions of a public speaker. the latter has very good advice on distilling your presentation to different degrees:

In effect, by working hard on a clear, strong, well-reasoned outline, I've already built three versions of the talk: an elevator pitch (the title), a five-minute version (saying each point and a brief summary), and the full version (with slides, movies, and whatever else strengthens each point).

the same methodology can apply to conversations at a bar or party, where you present yourself layer by layer, without the usual academic powerpoint crutch. this skill is essential in a place like cambridge, where your average craft brew aficionado also cures cancer or microlends in southern india or scans meditating monks in an fmri machine.

drink 1. this is prime elevator pitch time - you have to hook your conversationmate before they take two sips. i usually stick with the half lie 'i do rocket science'.

drink 2. ok, 'rocket scientist' worked, so now i can transition to what kinds of x-rays come from space, how we can best detect them on said rocket, and why this is important for silly things like carbon-based life forms.

drink 3. if you're still asking the right questions at this point, i'll be laying down terms like 'superconductor' and 'ionization state' to fill in the details between those earlier broad strokes. i'll be drawing graphs in the frost of your silver julep cup. i'll describe the mechanics of a supernova so vividly that you won't even think to make a joke involving the oasis song.

further drinks. well, at this point i would hope to have segued to something more entertaining, like cocktail history. otherwise, i'd be yammering about the best kinds of tape for cryogenic purposes, and that's not good for anybody. but at least none of my julep diagrams would use comic sans.

freeing the butterflies

[by john]

the pernicious condition of butterfly collecting can befall any experience-trapper - cocktail nerds, foodies, movie buffs, and travelers alike. the original pastime, once enjoyable, collapses to single-minded pursuit of a checklist of must-have specimens. naveen and i have talked plenty (and he even posted [twice]) about this problem, but still i fell into it.

my dc experience in january set things in stark perspective - the expectation-free neighborhood joints, like bourbon for no-hassle cocktails or fireplace for no-frills beers, outshone the capital-c cocktail bars that i, as a capital-c cocktail lover, was obliged to visit. it was as if i went to a country for the passport stamp, not the experience.

each of the 26 cocktail blogs i subscribe to has made it increasingly clear that, no, i cannot keep up the joneses with all three chartreuses and every arcane amaro in their home bars, nor their launch party invites, nor their historical knowledge. but hell if i can't enjoy myself with a drink in my hand! a few recent experiences have shown me that i don't need to kill each butterfly to ensure enjoyment:

genever & rum

i threw a party as an excuse to catch up with some friends i hadn't seen for a while. unlike the last two day festival, i actually relaxed this time. chatted, joked, didn't pin myself behind the bar...like a host ought to do. and yet i managed to introduce just about everybody to the oddities of genever and the joys of rum, with a damn good menu to boot. and as satisfying as that was, mixologically, it was more pleasurable to hear about grandmothers' recipes for pâté and fine dining faux pas.

italian on st. patrick's

as i sedulously examined the cocktail menu at coppa, the newest south end hotness, my friends chided me: 'are you gonna blog about this?' 'no', i retorted. clearly, i lied, but for a different reason - instead of taking notes on the creative workarounds for a place without a full liquor license, or a forgettable genever and yellow chartreuse cocktail (how far i've come to say that!), i chose to enjoy the palpable giddiness at the table from the vermillion pitcher of aperol and springlike weather in mid-march. the duck prosciutto and gossip didn't hurt the memorability, either.

four nationalities walk into a bar...

after beers and whiskey at a typical boston irish pub, i decided to drag three foreign visitors to green street for cocktails. it's always fun to nudge people outside of their beer comfort zone, and even more so when the colonizers (the briton and dutchman) had already traded barbs with the colonized (the american and south african). the cocktails were fine to bad (rum and fernet? never again.), but the conversation was excellent - health care, wal-mart, the superiority of the south african accent for picking up girls, dirty secrets of radio astronomy... who cares what you're drinking if that's how you're talking?

The Science of Whipped Cream

[by Naveen]

Whipped cream has been on my mind a lot lately. A classmate and I just gave a presentation about our experimental studies on the physics of these aerated dairy emulsions for an Applied Physics class that we're taking. People have made whipped cream since at least the mid 1600's, but it has only become more common in the past hundred years thanks to centrifugation (to separate out cream from whole milk), refrigeration (to shorten the whipping time and make stiffer foams), and pressurized nitrous oxide dispensers. Even more recently, scientists have begun to examine its micro-scale characteristics.

From a physical perspective, whipped cream is more complicated than most typical foams, which are just a dense packing of air bubbles held together by surfactant (like soap). The air bubbles in whipped cream are all coated with fat molecules, which is why it tastes so good, and why you need to start with about 30% fat content in the cream. These fat molecules are initially contained within a coat of proteins, but somehow need to escape to attach to the entrapped air.

The physics of mechanically whipping cream is fairly well understood. The whisk introduces large air pockets into the cream, which break into smaller air bubbles. At the same time, the whisking breaks down protein-coated fat globules in the cream, which allows naked fat molecules to adhere to the air bubbles. If the temperature is slightly above freezing, then the blobs of fat only partially coalesce, leading to a more rigid structure.

However, whipped cream that comes out of a can or nitrous oxide-powered dispenser follows a completely different process. The gas is initially dissolved in the fat globules, but comes out of solution when the pressure is released and the whipped cream is dispensed. With the traditional method of making cream, large air pockets are fragmented into small air bubbles. With aerosolized whipped creams, dissolved gas expands to form the air bubbles. We wanted to know how the resulting creams differed.

To be more quantitative about the mechanical properties of the various types of whipped creams, we put a small amount of each in a device called a rheometer. The device consists of two parallel circular plates that can rotate relative to each other in a controlled way. By placing the whipped cream between the plates, we can measure how viscous (like honey) or elastic (like a rubber band) the material behaves. In one experiment we rotated the plates back and forth over a range of frequencies and saw how the mechanical properties of the whipped cream changed. I'd be happy to discuss the results in more detail, but the basic idea is that additives in store-bought whipped cream make the whipped cream less elastic, but more stable.

We also did some preliminary microscopy measurements. My favorite was the confocal fluorescent microscopy, in which we added a lipid-soluble dye that revealed the location of all the fat globules. In the image below, you can see the fat globules clustering around an air bubble (the field of view is about 0.2 mm).

These early experiments are far from rigorous, but they do suggest all types of further studies. There is no shortage of variables to control: the amount of surfactant, the types of fat molecules (e.g. saturated vs. unsaturated), the protein composition (pasteurization can have a major effect), the air bubble size distribution, etc. Moreover, chefs are finding all types of novel uses for the refillable whipped cream dispensers, such as making espumas of seafood, mushrooms, and vegetables, as well as single-serving cakes.

On the agenda this month: the science of chocolate.