Carbonic maceration

Carbonic maceration is an old winemaking technique that is very much in vogue today, as it is one way to produce the sort of fresh, low-tannin glou-glou wines that those in the in-crowd are clamoring for—you know, the type of wine that you guzzle from an old jug with XXX stenciled on it during a hot summer’s eve on the porch while your old hound scratches at her fleas as you creak back and forth on granny’s rocking chair, hoping in vain to catch a faint breeze. Received wisdom would have it that the technique originated in Beaujolais, but if you examine the techniques employed in historic winemaking regions you’ll see that carbonic maceration, avant la lettre, is a very old method indeed—found even in Rioja, Bordeaux and likely Champagne practiced long before the rise of machine harvesting in the 19th century.

The recipe for making carbonic macerated wines is thus: take whole grapes and, trying not to crush them, carefully load them into a vat and seal the lid. Then, if you are in a hurry, pump in a bit of natural carbon dioxide, or if you are not, don’t (the grapes will, in time, generate CO2 on their own) and then go away and leave the vat alone for a week or so. Maceration means soaking, and here, we’re soaking grapes in carbon dioxide.

We partially understand what transpires next, but some magic remains a mystery. We know that in the absence of oxygen, grapes metabolize their sugar and begin to ferment at the intercellular level, without yeast, generating a bit of ethanol. This magical process also generates a spectrum of fruity aromatic esters (sometimes, you’ll hear folks using the adjective “bubble gum” to describe the aromas of carbonic macerated Beaujolais, but this is incorrect—the bubble gum aroma is a function of the 71B yeast strain exploited by conventional Beaujolais producers). In addition, the resulting wine will tend to be juicier and lower in mouth-drying tannins. And don’t get me started on intercellular fermentation and succinic acid, unless you want to be so bored, you’ll need both a double shot of espresso and a couple of clothespins to keep your eyelids from shutting. Intercellular fermentation gradually weakens the skins of the grapes and eventually, the grapes collapse and die, poisoned by their ethanol and releasing their partially fermented juice. Now, don’t feel bad for the grapes, as they’re dying doing what they love, which is to give us pleasure.