The grape growing season in several parts of Australia has got off to a challenging start as a country-wide heatwave brought record-breaking temperatures.
A state of emergency was declared in New South Wales (NSW), where there were concerns the heat could exacerbate existing wildfires near to Sydney, while fire risk was being monitored closely in South Australia and Victoria.
While fire crews and authorities have naturally prioritised the safety of people and property, there were concerns that grapes in Hunter Valley could be at risk of smoke taint from the bush fires in NSW.
There was also a higher risk of sunburn parts of South Australia and Victoria, where temperatures soared into the mid-40s (Celsius) on Friday.
University of Melbourne viticulture professor Snow Barlow told The Guardian that smoke taint represents a serious risk in Hunter Valley, because veraison here begins in early January and bushfire smoke can enter the grape through the skin during the ripening period, causing the fruit to carry unpleasant smoky notes into the wine.
‘I think there’s a good chance they will have smoke taint,’ said Barlow. ‘They [Hunter Valley] are looking to be the most affected of the major wine growing regions.’
However, grapes that have been sampled and tested in the Hunter Valley and other regions have shown no signs of smoke taint yet.
In South Australia’s Barossa Valley the concerns among growers and producers were centred on the heatwave, as many vineyards here are not irrigated.
Vines can drop leaves in extreme temperatures if they become heat-stressed, which increases the risk of sunburn to the fruit. However, it depends how long the heatwave lasts, with shorter spikes more manageable – as was seen in France earlier this year.
‘It is ominous getting 44C, 45C days at this time of the year,’ Barlow said. ‘But if vineyards are going to have these temperatures it’s better to have it now than to have it after veraison.’
Vineyards with irrigation systems and access to water will be able to manage their vines through the heatwave, but those without might struggle.
‘For the next few months, irrigation management is going to be critical for most growers,’ said the president of the New South Wales Wine Industry Association, Mark Bourne.
‘These extreme weather events are of great concern to the wine industry. We can’t choose not to plant a crop, we can’t sell off livestock. We’ve got permanent crops in the ground and we have to choose how to manage them.’
Australia has already experiences its driest and second warmest spring on record.
Editing by Chris Mercer.