From green waste to wine

You’ve heard of red and white wine. You might even be a fan of rosé or orange varietals. But what about green wine?

Sustainability Victoria is supporting a group of winegrowers in the state’s north to trial the use of compost made from organic waste from Melbourne’s green bins under their vines.

The benefits of compost are becoming more widely understood in agricultural settings. But the cost and availability of both the compost and the machinery required to spread it under grapevines means it’s not as widely used as it could be.

Thanks to a grant from Sustainability Victoria, the Heathcote Winegrowers Association is now conducting a trial to increase confidence in using compost among its 64 member vineyards.

Trial participants will have access to high quality compost from local composter BioMix as well as specialised machinery at a low cost. The machinery, funded by Sustainability Victoria, is stored in a local community shed and can be booked out for periods of time by participant vineyards.

Hugh Jones from Heathcote winery Humis says “the jury’s in” when it comes to compost benefits, but it has proved to be unaffordable for many small vineyards.

“There’s always been an appetite for using compost in our wine region, but it’s been difficult to do it at a scale where it will really make an impact,” Hugh says.

“Through the trial, vineyards can access two tractors, a spreader and a pressure washer at a reduced cost, along with much cheaper compost from BioMix."

Madeleine Marson from Vinea Marson agrees, explaining that the availability of the equipment within the Heathcote wine region reduces the biosecurity risk of hiring machinery from other areas.

“Before the trial, we were having to go out of region to hire this equipment, sometimes to 3 or 4 different regions,” Madeleine says.

“This brings with it a biosecurity risk in terms of phylloxera, which is a tiny insect that destroys grapevines by damaging the roots. There are a lot of protocols in terms of cleaning that we have to follow.

“Logistically, it is time-consuming and expensive, so if we can provide this machinery through our own community and at the same time, increase the sustainability of people's viticulture by using a recycled material, it's a win-win for everyone.”

A natural weed suppressant, compost also improves the water retention capacity of soil while adding important micronutrients.

All of this produces climate-resilient vines delivering more consistent fruit which winemakers love.

Madeleine says compost also keeps the soil cool which is becoming more important as global temperatures rise.

“This means that the vine is better able to cope with the stress of extreme heat events physiologically,” she says.

“That has a whole range of benefits in terms of overall vine health, but also development and quality of the fruit.

“We have shorter growing seasons when it's hot, and our alcohols get really high without the flavour development that we want in the grapes, so the wines are more one-dimensional.

“By using compost, the fruit develops more evenly without massive extremes when your sugars jump up, but your tannins and your acid brightness are tracking way behind.”

The compost produced by BioMix in country Victoria uses garden waste collected from kerbside bins in inner city Melbourne.

This means that as more farms and vineyards use more compost in their practices, it becomes even more important for householders to find out exactly what items go into which bin so we don’t contaminate the soil growing our food and wine.

Madeleine says the compost trial has impacted her daily life away from the vineyard.

“I’m also thinking more about what I’m buying and what I will then throw out.

“At our cellar door, we’ve got a real opportunity to talk to our customers about why it’s so important to reduce contamination in our waste streams.

“As awareness grows, hopefully we’ll see a corresponding improvement in the quality of our compost.”