If a beer’s foam is its “head”, are the bubbles that create the foam “think bubbles”? And if so, what thoughts are in those bubbles? Is this where a beer’s consciousness and identity reside? And if so, what does that tell us about the identity of a beer without foam?

Four of five years ago, photographs of glasses filled with utterly foamless beer, to the agonizing point of spilling-over, began to proliferate on Instagram. For reasons lost to the vicissitudes of time (but perhaps related to the Instagram handle of the supposed originator of the idea), this mode of beer presentation became known as “the Iceman pour”.

The trend has resulted in thousands of arresting images. It seems to have fed upon—and perhaps to have fed into—the trend for massively dry-hopped, opaque, translucent pale ales. Pouring without a foam is a further insistence on the essential fruit-juiciness of this beer style, embodied by its aroma, flavour, colour and opaqueness. It also creates a strange illusion of solidity: the glass of beer in the image could just as well be a glass-shaped block of mango-coloured plastic.

Arresting, then—but, as the “Iceman” epithet inadvertently acknowledges, also a triumph of aesthetics over warmth, even over life itself.

An Iceman pour is magnificent in the same way as the wall-mounted head of a stag is magnificent. Either way, removing the head achieves a sense of melancholy deadness, a deadness that persists in spite of the reanimating art of the taxidermist or the photographer.

The most highly-praised examples of the Iceman pour take the practice to such an extreme place that the meniscus of the liquid is perceptible over the rim of the glass.

Contrast the cool precision of that aesthetic statement with the riotous clamour of the bubbles of a Bavarian Weiβbier or a Belgian ale, surging in their bid to escape the confines of their glasses.

Here is a curious combination of profligacy and pragmatism. Our cups runneth over, but thanks to the magical physical chemistry of the surfactant hydrophobic polypeptides that survive the brewing process, no beer is spilled.

Foam is a splendid visual articulation of the gregariousness of beer. There is something frivolous about it. It laughs in the face of the “serious” beer drinker. It dabs him on his nose!

But it also articulates something about the temporary and bounded nature of the social abandon that serious people—people with real work to do—permit themselves. Foam, like the expanding universe, contains the elements of its own demise. It forms as surfactants lower the surface tension that causes bubbles to coalesce and collapse; but as those surfactants create bubbles, they massively increase the surface area of a liquid, generating even greater surface-tension forces. Those forces, of its own creation, will eventually render the foam unstable.

All good things must come to an end, say my congregating, coalescing, frivolous beer bubbles.

Beers made for leisurely contemplation tend to be modest in their foaminess. Alcohols—and especially higher fusel alcohols with long carbon chains—inhibit foam formation. That feels appropriate. Our cups should not run over with Imperial Stout. A Barley Wine does not wish to be bantered and brayed over.

And yet, who would be without that collar of café-crème, or that cap of fine-bubbled caramel, which whispers to us, “I am still a beer, in my deepest essence—I am no gaudy fizzing Champagne, nor some lugubrious spirit”?

The blackness of an Imperial Stout is the blackness of space. Its death-defying sliver of silver is a milky way of stars. The foam of my beer tells the unfinished fairy tale of this universe, from Big Bang, through miraculous self-reflection, to maximum entropy.

The Iceman pour was perhaps less of an innovation than we assume.

There is something in cask-ale culture that has long looked with distaste upon an abundance of bubbles. In this world, quite at odds with that of the bottle-conditioning Belgians, fizz is foreign. The bartender who can pump a pint of Bitter to the meniscus-straining lip of a session glass achieves the approbation of the penny-pinching pub-goer.

These old geezers were the ur-Icemen.

Do I commit an injustice against them? Is this an aesthetic choice, rather than one of economy? Or perhaps an ideological one—a manifesto statement on the seriousness of cask ale? Do they insist that the madding, ladding, louting loudness of the communal beer bench jars against this delicate living liquid as much as it would against a ponderously contemplative Barley Wine? The appropriate session for this golden nectar is one with my broadsheet newspaper in a darkened corner of an oak-panelled saloon, these drinkers seem to say, sipping, nursing, letting my thoughts succumb to the slow oxidation of pensiveness.

Then again, if we were to head north we might meet cask ale drinkers who pursue bubbles. They frown upon public houses that fail to deploy “sparklers” on their beer pumps, that little bit of kit which excites the cask ale’s latent carbon dioxide to render itself, reluctantly, as a film atop a pint of Best. But they would frown all the more if those same landlords failed to compensate for this bubble fetish with taller glasses, to prevent the short measure. The overflowing superabundance of the truly gregarious beer foam is not for these drinkers. Somewhere in history, what the foam represents has been lost to the march of grim utility, leaving this sad sparkly echo behind.

Yes: a beer’s foam is its head, and the bubbles that create the foam are think bubbles.

To remove the head is to rupture the beer’s consciousness and subjective identity. To attempt to stitch another head back on is to fall into the Frankensteinian error that, having all of the physical elements present and correct, one can simply galvanise consciousness back into existence.

The true mystery goes unacknowledged—the momentary spark of a living, thinking, super-complex organisation of energy, which prophesies its own entropic heat death; the blink of an eye during which the surface tension of a cold, black, flat universe is resisted, and bubbles of individual identity strain to survive, before they pop! back into near-nothingness, like virtual particles, like spheres of consciousness.