The most sustainable whiskies you can buy now

GRAIN, water, yeast - and CO2? On average, crafting a single 750-millilitre bottle of liquor results in some 6.5 pounds of carbon dioxide being released into the atmosphere, equivalent to burning a third of a gallon of gasoline, a recent report from the Beverage Industry Environmental Roundtable concluded.

Specifically, making whiskey is such an energy-intensive enterprise because it requires weighty raw ingredients to be trucked over long distances. And distillation itself is a largely inefficient process - heating the stills and maintaining temperatures only to keep less than 40 per cent of the final distillate once you discard the heads and tails. An immense amount of grain produces relatively little liquid: Approximately 100 kilograms (222 pounds) of cereal will make 600 litre of mash, yielding up to 87 litres of 80-proof whiskey. Creating all those barrels and glass bottles has an immense carbon footprint, too.

As with other industries, consumers are demanding better, and whiskey makers are clamoring to claim at least some commitment to the cause.

Buffalo Trace - among the biggest whiskey makers in the US - recently joined with the University of Kentucky to help promote the long-term sustainability of white oak, the wood used to make bourbon barrels. Johnnie Walker, the world's largest Scotch producer, is ambling in the right direction with its Next Steps Initiative, which pledges to reduce the distiller's carbon footprint by 15 per cent before 2030.

An ecological approach can also be an economical one in several key elements of production. Harnessing the heat of wastewater in a closed system, for example, is ultimately cheaper than paying to have it treated and reintroduced to the municipal supply. Gifting the spent grain of fermentation as cattle feed sidesteps the cost of having it carted away as refuse. Growing your own grain is even better.

Advancements in solar technologies, heat reclamation systems, rainwater collection, and ways to more efficiently direct energy and temperature management are being built into operations including Company Distilling, a project from Jack Daniels's former master distiller that's set to open later this year in eastern Tennessee.

Anaerobic digesters have come a long way since they first started making their way into distilleries in the 1980s. It's not uncommon for operations to produce 30 per cent to 40 per cent of their energy from the waste/spillage that they create during production.

Here's a look at some bottles you can buy now that have already been maximising green in the grain in a real, impactful way.

Marble Distilling Co: For its Hoover's Rvenge Ragged Mountain rye (US$66), this Carbondale, Colorado-based distillery sources its grains from a farm less than a mile away. A full 100 per cent of the water used on-site - from fermentation to distillation, to proofing down, to heating and cooling - is reused, saving more than 4 million gallons of runoff per year. The whiskey itself is round and robust, thanks to the inclusion of high-altitude wheat in its mash bill.

Bowmore: Malting is the process by which barley is heated and readied for fermentation. Although in Scotland it was traditionally done on perforated floors at the distillery, it largely takes place off-site in massive industrial kilns these days. Since 1984 on the Hebridean isle of Islay, Bowmore has been utilising a heat recovery system to keep the past alive - and low impact. Hot air rolling off the stills is piped to the malting floor during the heating process. The system also heats the local community pool, which sits in what was once a distillery maturation warehouse. And even as Scotch prices soar, the 25 Year Old single malt (US$400) remains one of the best value luxury labels on the market.

Blinking Owl: Ever since it opened in 2013, this Orange County, California, craft outfit has neurotically pursued the goal of offering a 100 per cent state-grown product. Beyond keeping things as local as possible - removing the diesel fuel inherent to long-distance sourcing - Blinking Owl works almost exclusively with organic producers and growers who employ sustainable farming practices. A limited edition Bottled-In-Bond bourbon (US$250) is easily among the tastiest American whiskey releases of 2021.

Belgrove Distillery: This estate operation from Tasmania, in the far-flung corner of south-eastern Australia, is fashioning the rye grain into their eponymous A$155 (S$159) Belgrove rye whisky, which is sturdy enough to rival the best that Kentucky or Pennsylvania has to offer. It's birthed from the world's first - and only - biodiesel still, fuleled by waste from a local fish-and-chip fryer. Owner Peter Bignell grows his own grain and feeds leftover mash to his sheep. He's even considering using their dung in lieu of peat to smoke future batches.

The Macallan: Opened in 2018, the Macallan's new US$200 million home is a stunning structure with undulating contours meant to protect the water of the nearby River Spey, the very heart and soul of Speyside whisky. The entire operation is capped under one of Europe's largest green roofs, spanning just over 12,000 square metres. It's planted with a mix of native grasses and herbs, providing food and nesting space for birds and insects and regulating thermal transfer into and out of the facility. A water management system returns cooling water pulled from the Spey to the rolling river in full, absent only a scant amount of evaporation.

Scotch, by law, has to be a minimum of 3 years old, so very shortly we should see some of this sustainably produced liquid working its way into some non-age-statement expressions. In the meantime, every bottle of Edition 6 (US$150) funds a charitable partnership between the distillery and the Atlantic Salmon Trust.

Maker's Mark: In Loretto, Kentucky, one of the world's biggest bourbon brands had been using its spent grain as an alternative source of fuel for its signature wax-dipped bottles (US$30). "Thick slop" - as it is affectionately referred to in the industry - was treated aerobically in a reactor. The result was a high-methane biogas, which was collected and compressed before being fed to the boilers (and byproducts from that fed to cattle). It accounted for a 25 per cent reduction in natural gas consumption at the distillery from 2010 until 2013. Some of that liquid is just now exiting the barrel eight years later. BLOOMBERG