The gin market is awash with hundreds of brands all jostling to get in on its seemingly never-ending boom. In the U.K. alone there are now 820 gin distilleries, but only a handful of these work through the whole production process from grain to glass. Most Gs awaiting the splash of T — from small, boutiquey brands up to some of the world’s best-known gins — are built on base alcohol bought in bulk. Their marketing may gush about artisan this and locally foraged that, but the botanicals are just the dab of perfume behind the ear of a body that comes courtesy of the agroindustrial supply chain.

Gin’s Genome

Drinks industry types sometimes explain gin as, “vodka redistilled with botanicals to give it extra flavor.” It’s a half-truth at best; in reality, it’s more like gin and vodka are brothers from the same mother. Her name is neutral spirit.

Vodka is the reserved firstborn. It presents its neutral spirit to the world largely unaltered — with just a smidge of redistilling and dilution so you won’t go blind drinking it. Meanwhile, gin is the showy younger child, hungry for attention. It redistills its neutral spirit with botanicals to add a piney whack of juniper plus whatever else it can grab. Citrus? Cardamom? Come on down! Cubeb? Why not?

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What the two drinks have in common, neutral spirit, is just that: neutral, made to set the stage on which other flavors strut and fret. That’s not to say it doesn’t add anything at all. Besides the obvious benefit of making a drink alcoholic, a base spirit will also contribute structure and texture.

The Hard Stuff

Brands that make their own neutral spirit usually spin it into an origin story that helps sell a fair few bottles. So why don’t more of them do it? It’s not that they’re (all) fly-by-night operations — even established brands like Bombay Sapphire and Beefeater don’t bother. The answer is, in short, that making a neutral spirit is no small feat.

Gin distillers use pot stills, but when it comes to ABV, these can only get you so far. Running hooch through once gets you up to maybe 35 percent. Twice gets you to 70 percent, but then diminishing returns kick in as energy put in decouples from alcohol taken out. Three times through the still gets you 80 percent if you’re lucky.

To call your distillate a neutral spirit, you must reach 95 percent ABV or 190 proof in the U.S.A. Such a high distillation strength requires a column still, and these take up more space and eat up more energy than pot stills. They’re also more complex, so there’s more to go wrong. In the E.U. and the U.K. distillers need to go one step further, to 96 percent ABV. This may not sound like a big difference, but it’s huge in practice, much like how a magnitude eight earthquake is not simply one step up the scale from magnitude seven, but is actually worse by a factor of 10.

Moreover, distillers wanting to make neutral spirit need to ferment the liquid they want to distill. This means using more energy for heating and cooling, giving over space to raw materials and equipment, and fussing about with yeast, only to be left with more waste to dispose of once the booze has been extracted.

Even before the invention of column stills, distilling was divided between the “agricultural distillers” who made their base spirit and the “rectifiers and compounders” who turned it from an ingredient into a drink. Basically, it’s more efficient for distillers to turn grain into high-strength booze near where it grows and ship that around the country, rather than hauling all that produce into the towns and distilling it there.

Still, the reason most gin brands buy ready-made base spirit comes down to cost. Making it can add $5 onto the cost of a bottle of gin that may cost $30, while base alcohol can be bought in for mere cents on the gallon. The question is no longer why do so many gins buy in their base spirit, but why do brands ever bother to make their own?

Touching Base

Legally speaking, gin is fussy about its flavorings, which must be predominantly juniper. But unlike most spirit categories, which specify the base ingredient from which they may be made — Scotch whisky must be all barley but bourbon must be at least 51 percent corn — gin can be made from anything, even whey.

Which is how I found myself next to spirits educator Hannah Lanfear and opposite an array of neutral spirits made from wheat, sugar cane, molasses, potato, grape, corn, and rye. Half past 10 on a Tuesday morning, and there we were not sipping but gingerly touching our tongues to very nearly pure ethanol.

It made for quite an experience. The liquid evaporates almost at once and fills your head with a snootful of fumes carrying on them just a tinge of aroma. After the initial shock, you start to pick out impressions of texture on your tongue and lips. At first it’s like trying to spot the difference between seven samples of pure white paint, but some do eventually emerge.

“Ethanol is ethanol,” said Lanfear. In other words, it doesn’t vary. “But distilled to this strength, there’s undoubtedly different qualities to it. That must be minuscule levels of volatile compounds that are above the human threshold for detection.”

For instance, we both agreed the wheat spirit — the same stuff used to make Gordon’s and Tanqueray — was soft and doughy, with just a touch of citrus. The corn spirit surprised us with nutty aromas like toasted sesame seeds, and was notably smooth. And the molasses spirit hinted at a caramel warmth that opened up on our palates once diluted — this is the base spirit for Monkey 47 gin. “I’m really impressed with the texture every time I taste it,” said Lanfear.

For the finished gin, the contribution from its neutral spirit boils down to the polish. What little character there is in neutral spirit will mostly disappear behind the botanicals added later in the process. What still shows through is how well “integrated” the alcohol is. This is what we mean when we talk about gin’s texture: Does it prickle and burn or is it smooth and pleasantly warming?

Ultimately, very few distillers can make a base alcohol that you’d want to drink while keeping their gin at a price you’d want to pay. And perhaps that’s for the best — distillers buying in neutral spirit means everyone involved in making your favorite gin can play to their strengths. The big guys make the canvas on which the little guys get creative. After all, you wouldn’t castigate a painter for not making her own paint — it’s the art she makes from it that matters.

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