Upcycling wine from spit buckets into brandy? Only at Rootstock.

Grappa di Saliva. Grape Expectorations. Eau de Crachoir. The Spitting Image. Marc de Ptooey. When you're trying to come up with names for a spirit made from wine salvaged from spit buckets, inspiration is never far from hand. Nor are strong opinions. Even the drinkers who know in their rational minds that the distilling process leaves impurities in the bottom of the still, and that alcohol is a very effective antibacterial agent profess a certain unease about the idea. But that's all part of its magic - and it's all very Rootstock.

This year the Sydney artisanal wine festival ramps up its waste-fighting bona fides with a pledge to take the wine from its spit buckets (that is, for the uninitiated, the receptacles into which wine that has been swirled around the mouths of tasters has been spat) and ends of bottles and distil it. Brandy, after all, is simply distilled wine, and distilling is, apart from a way of making alcohol, one of the oldest and most reliable purification processes known to man.

The idea - and it might even be a world first - grew out of a conversation in a session at Rootstock in 2015 that was all about artisanal distilling. Hosted by your correspondent, its speakers were French eau-de-vie producer-to-the-stars Laurent Cazottes and Peter Bignell, owner of Tasmania's innovative Belgrove Distillery . At Belgrove, Bignell heats his water, runs his truck and forklift and fires his still with biodiesel made from cooking oil from the roadhouse next door. He grows his own rye corn and collects water from his shed roofs. "The only significant material I bring to the farm is waste cooking oil and the only product to leave is whiskey," he says.

Bignell has taken bread and food waste left over from other events and transformed them into vodka, and so when talk turned to the idea of finding a way to put the waste products from the festival to better use, he was all for it. In organising this year's festival, Rootstock's directors (former GTSommelier of the Year Giorgio De Maria among them) turned to Marrickville gin distillers Poor Toms to simplify logistics and cut down on spit miles.

"Giorgio said to us 'I've got this crazy idea. Would you be interested? I think a lot of people are going to be disgusted by it,'" says Poor Toms co-owner Griffin Blumer. "But he also said 'I think it's going to be a really cool story and people are going to really get behind it, and hopefully it'll teach us all something not just about recycling but about alcohol and what goes into sprits,' and creating stories is what we're about at Poor Toms. Our gin is storytelling for us, so we wanted to get involved."

Poor Toms' Müller still, Blumer says, was designed specifically to help farmers and small operators to turn their fruit and farinaceous crops into brandy, so it's an easy (ish) leap from there to upcycling wine.

How much wine? "I'm not sure exactly, because a lot of Rootstock visitors prefer to swallow," says De Maria, but by his conservative estimate, the festival's 65 producers open an average of 60 bottles of wine over two days, making for more than 3,400 litres of wine poured. "So it'll be a lot of spit."

From that, Blumer and fellow Poor Toms founder Jesse Kennedy hope to salvage 200 litres of wine a day. They'll let it settle overnight in a coolroom, and then distil it the following morning. They're expecting a yield of around 20 litres of nearly pure alcohol from each run.

Some of that spirit will go into oak barrels to age, like brandy, and some will go into stainless steel, and will more closely resemble a grappa or marc. From there its final destination will be cocktails at Rootstock 2017, and a special reserve barrel, which will be auctioned to raise money for Gurandji Munjie , one of the charities supported by Rootstock.

We asked Tim Philips, co-owner of acclaimed Sydney bars Bulletin Place and Dead Ringer, for an idea of how such a singular spirit might best be deployed. "Besides being a post-dinner sipper, grappa works as seasoning in more austere stirred cocktails," he says. "Replacing the Scotch in an Affinity for example. Long story short, I'd love to get my hands on some."

Are there any health concerns about the brandy? "In the final cut that we have?" says Blumer. "No. The still boils the wine, then the alcohol comes off before the spit or water, and you can't distil viruses or bacteria. And beyondthat, alcohol is an antibacterial agent itself anyway. That aspect of it is the first thing that intrigued me, though - it's still an unsettling thought."

And the taste? "I have no idea what to expect," says De Maria. Brandy isn't usually made from finished table wines, let alone wine made by producers of the calibre of Philippe Bornard, Jean-Jacques Morel, Olek Bondonio, Vanya Cullen and Taras Ochota. And it also hasn't usually been pre-slurped by impassioned festival-goers. It's anybody's game.

"Don't tell the French I said this, but the stuff in the barrel might be a bit like Cognac," De Maria says. "Only with the saliva twist that gives it its Rootstock terroir."