MOG – what is the impact and why should you care?

RD&A News | June 2021
11 Jun 2021
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Grape harvesting mechanisation in the 1960s was a gamechanger for Australian growers and winemakers.

But with the benefits of faster, more efficient harvesting came the downside of MOG (matter other than grapes) – an issue that continues to be a headache for the sector more than half a century later.

Dave Gerner, Wine Australia’s AgTech Program Manager, is at the forefront of the management of MOG and is working collaboratively with industry on emerging new technologies.  

He said while the upside of mechanical harvesting has far outweighed the unwanted by-product of MOG in the supply chain, the impact of MOG remains a significant challenge.

‘Many of the larger companies would have different perspectives on the cost and imposition of MOG in their supply chain, and there is still a diversity of opinion as to who pays for this’, Dave said.

‘For example, the cost of transporting fruit containing MOG from the vineyard to the winery – and then the need to remove that MOG at the winery – is largely unmeasured as a sector.

‘Then you have the consideration of the cost of production and related efficiencies at the winery, as MOG creates bottlenecks at the crushers as production systems slow down to accommodate destemming and sorting.

‘These breakdowns and mechanical failures are frequent and expensive.’

Finally, there is the consideration of wine quality outcomes as a result of MOG.

‘It’s no secret that generally wines produced from MOG-free picks are brighter, have better colour and provide winemakers with more flexibility to create the wines they desire. A lot of research has been done in this area to evaluate the wine quality benefits to clean picks, and in most cases, the science supports the view of many winemakers, who would choose clean, MOG-free fruit.

‘We also know that selective harvesting reduces berry maceration, which slows down the onset of biochemical reactions pre-fermentation and puts a greater degree of processing and winemaking choices back in the hands of a winemaker.

‘The challenge with MOG is that berries that travel from vineyard to winery for processing can be in contact with the juice for up to 12–18 hours, so you can have complications that come with that’, said Dave.

However, Dave said one of the conundrums for growers was that there was little incentive at the moment to provide ‘clean’ fruit. So, a consideration for the sector in the future is how do we incentivise adoption of MOG-free fruit harvesting?

Innovation to produce clean harvested fruit has been enabled by Australia’s trend to produce premium quality wines – and has resulted in many major equipment providers now offering ‘selective harvesting’ capabilities.

However, each system or piece of equipment had its own pros and cons.

‘For example, in-field selective harvesters deliver premium picks, but the equipment can be expensive’, explained Dave.

He said while many large vertically-integrated businesses had invested in selective harvesting equipment, they were then challenged with ‘triaging’ what blocks got the premium pick.

Looking forward, Dave said there were new technologies on the horizon that had the potential to provide cost-effective MOG-free fruit harvesting to a wider grower-base.

‘As a sector we have an opportunity to work together on solutions to this generally unwanted by-product. It is only then that we will see some wide-scale benefits for growers, winemakers and the sector as a whole.’

In future issues of RD&A News, we will present some of the new technologies providing solutions to this issue in greater detail.


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This content is restricted to wine exporters and levy-payers. Some reports are available for purchase to non-levy payers/exporters.