Chilling out in Australian wine’s own Ice Age

Chilling out in Australian wine’s own Ice Age

THE FIRST AUSTRALIAN Iced Riesling made its debut in 1995 and was pioneered by Tasmania's Andrew Hood under the Wellington brand.
Over the years this dessert wine developed a small, yet loyal, following so when the winery was sold to Frogmore Creek it is no surprise the new owners resurrected the Iced Riesling under the new label in 2004.
Since then, this Coal River Valley winery has expanded its dessert range to also include an Iced Gewurztraminer in 2010 and 2011.
With night temperatures in Australia not being cold enough to freeze grapes on the vine, Frogmore Creek has developed a cryo-extraction freezing technique that can adapt to the country - and the climate.
According to Frogmore Creek's Alain Rousseau, the success of the cryo-extraction process relies upon using grapes that are ripe and ready for wine making. This is because perfectly ripe grapes will have a higher sugar content than grapes that still need to ripen.
Consequently, the truly ripe grapes will freeze more quickly and the juice from the frozen grapes will have a greater concentration of sweetness and flavour.
'As our climate doesn't allow for the natural freezing of grapes on the vine, we harvest the fruit with the highest sugar content (around 14 baumé),' Rousseau said.

Once the grapes are picked and cleaned, they are placed in a freezing tank with floor jackets that is directly connected to the compressor to freeze the grapes.
'We then start a freeze concentration of the juice in special tanks. It takes four to five days to have the tank full of solid ice,' he said.
'After that, we pump the concentrated juice through the bottom valve. This operation takes a few days as the sugar is quite thick and it takes time to run down through the ice block,' Rousseau explained.
'We then press the grapes as soon as possible and settle the juice in a tank. The juice is kept for a few days as clear juice, with no lees, at a low temperature to avoid the start of fermentation. The sulphur is kept around 20 mg/litre of free sulphur.'
The chilled liquid is then drained from the wine press, while ice crystals usually remain in the press.
This process is understood to produce the highest level of concentrated flavour in the liquid that is pressed from the grapes.
The juice has to be at 17.5 to 18 baumé before the start of the fermentation. Sometimes, it takes two concentrations to access the desirable baumé level.
The operation concentrates all parts of the juice: sugar, acid, flavours and sulphur. Rousseau said this was why the operation has to be done as soon as possible to avoid getting a level of total sulphur above legal requirement.
'After the concentration, the juice is then inoculated. The fermentation is slow due to the high sugar content, usually taking a few weeks at 15C temperature,' he said.
'We monitor the fermentation daily through analysis and tasting and reduce the temperature of the juice towards the end of ferment to achieve the desired alcohol and sugar level.
'Alcohol is around 7 per cent and sugar levels are around 200gr/litre,' he added.
Each day during fermentation, the wine is tasted and it remains in stainless steel tanks until 'D Day' arrives, where the wine is cooled down and sulphured and kept at 0C until filtration. The wine is then filtered and bottled, usually in September.
'The style of the Iced Riesling is very sweet (200 gr/litre of sugar), with fresh fruit (citrus and pineapple) and well-balanced acidity. It is very different from the botrytis style or the sweet honey and complexity of a traditional ice wine,' Rousseau said.
'We are losing about 40 per cent of the volume through concentration so the price of $26 per 375ml bottle reflects the amount of work and the loss.
'We cannot compare our method to the process used for making 'ice wine'; this is also reflected in the pricing.
'It is definitely a growing market for us, with Australia and Asia currently being our best performing sectors.
'We produced the Gewurztraminer with excellent results (a concentrate of rose petals; our own Turkish delight in a bottle).'

Following in the footsteps of Frogmore Creek, other Australian wineries have also entered this niche dessert wine market in recent times. In the Yarra Valley, Redbox Wines is producing an Ice Cabernet and Ice Riesling in its range using a freeze reduction technique. This process is used to enable the extraction of the water/ice content from the juice of the selected fruit. Once satisfied with the juice, it is then run through a ferment and stabilisation process before bottling.
On the west coast, Margaret River winery Fraser Gallop Estate is about to release its first iced wine - an Ice Pressed Chardonnay.
Despite the soaring temperatures experienced in Margaret River during the 2013 vintage, winemaker Clive Otto and his team trialled freezing three-tonnes of late picked Chardonnay grapes overnight in a commercial freezer at -16C.
The fruit, which was at 13.0º baumé sugar levels prior to freezing, was then pressed in the cool of the following morning with a Bucher XPF80.
The press was loaded with an elevator and set on the auto Ortal program to press quickly to a high pressure.
'We were excited when we inserted a hydrometer into the juice and were getting sugar readings of 17º to 21.5º baumé,' Otto said.
"The juice was settled overnight before draining to some new French oak barrels, some older barrels, and some steel barrels.
'In this way, we can get a better idea which vessel will suit this style. Maybe the blend of all three will be best? We don't know yet,' he said.
At this early stage, it is unclear whether local punters are developing a taste for our home grown version of 'ice wines' because they sell for a fraction of the price of their overseas counterparts, or whether we are simply developing a taste for such an intensely delicious style of dessert wine.


Alain Rousseau
Phone: 61 3 6248 5844.
Email: [email protected]

Clive Otto
Phone: 61 8 9755 7553.
[email protected]

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