Cryoextraction in Australia = increasing sugar concentration

Domestic freezer

In the light of the controversy over cryoextraction/cryoextraction sélective and Domaine des Baumard's 2012 Quarts de Chaume, there was an interesting news story published on decanter.com yesterday about a made 'ice-wine' in Western Australia. Clive Otto is in the process of making an 'ice wine' from grapes picked at 13.0˚ Baume (13.34% in potential alcohol. Freezing has raised the sugar level to between 17.0˚-21.5˚ Baume (in potential alcohol between 18.31% and 24.53%). 

This seems to indicate that in Australia, at least, as well as in Washington with the Pacific Rim Vineyards that the use of cryoextraction concentrates the sugars and can facilitate the making of sweet wine from grapes, which would not be sufficiently ripe to make sweet wine without freezing them.           

'Western Australia's first 'ice wine'

Monday 11 March 2013

by Danielle Costley

While Western Australian winemakers have been sweltering in soaring heats, Margaret River winemaker Clive Otto from Fraser Gallop Estate has been working in freezing temperatures to create his own 'ice wine.

Traditionally, ice wine is made in the cooler regions of central Europe and Canada from grapes that have been naturally frozen on the vine.

Otto is making a similar style of dessert wine by freezing late picked Chardonnay grapes overnight in a commercial freezer at -16C. The fruit, which was at 13.0º baume sugar levels prior to freezing, was then quickly pressed the following morning at a high pressure.

‘We were excited when we inserted a hydrometer into the juice and were getting sugar readings of 17º to 21.5º baume,’ Otto said.

Read the full story here.

Equally from the Pacific Rim Vineyards' blog on cryoextraction:

'The concentration process is fairly simple; when a grape gets frozen, the water freezes first and the sugar last – this is reversed when the grapes are thawed. If you follow me, when you thaw the grapes while pressing, you end up extracting all the sugar first, leaving the water frozen in the press thus concentrating your juice.'

On Wine Berserkers' forum there is a thread called Baumard "hits back" vs Jim Budd. Amongst the comments is one from Chris Kissack (the Wine Doctor) which is also reproduced on Chris' blog here. He provides a very clear statement of the issues involved. 

Some on Wine Berserkers have suggested that this is a very geeky controversy, which if you focus solely on the small but prestigious Quarts de Chaume may in part be true. I think, however, that the main issue is far more fundamental – namely the right of the consumer to be told the truth and to be confident that a product is what it says it. Surely this was the original motivation behind the establishment of France's appellation system: if you buy a bottle of Châteauneuf-du-Pape the wine comes from Châteauneuf and it has been made according to agreed and legally binding rules.  

Put into a current context if you buy a 'beef' product it should contain beef and not horse. There may well be a market for horseburgers or horse lasagne but the labelling has to be very clear.  

Cryoextraction and the Quarts de Chaume décret 

There continues to be confusion over the legality of cryoextraction under the 2011 Décret. Section 9 bans any lowering of the temperature of the grapes below -5˚C. However, section 11 – 'mesures transitoires' (transitional arrangements) states that this ban will be applied from the 2020 vintage.

In this transitional arrangement producers can only lower the temperature of their grapes if they have satisfied the first requirement relating to the harvest: 'les vins sont issus de raisins récoltés à surmaturité (concentration naturelle sur pied avec présence ou non de pourriture noble).' (wines have to be made from grapes that have become extremely ripe on the vine; noble rot may or may not be present).