Another chapter in the China travels series...
This time, its about something that was developed in Germany, really took off in Canada, and now it looks like China is poised to take over.
Ice wine. The luscious nectar made from frozen grapes, it is highly prized by some, and highly priced by many!!
Why is it so exclusive? To make the real stuff, the grapes need to be naturally frozen, and picked when the temperature is -8C or lower, and will stay that way until all the pressing is finished (these are Canadian rules - some other countries have their own regulations, but the Canadians seem to have the most comprehensive set, designed to ensure the integrity of their icewine (all one word, as opposed to the generic "ice wine" product)). That's pretty cold, and throw in the fact that it could be windy as well, and you're looking at a temperature of -16, easy, with the wind chill!
Wouldn't it be nice to be able to sit in a mechanical harvester and collect all those grapes into a hopper? It would be nice, but you wouldn't get many grapes that way, as by that time of the year, the cluster rachis has gotten brittle, and the berries fall off far too easily! So the grapes must be hand picked! Sometimes in the dark, when it's the coldest and to ensure that the grapes do not get above -8C. Similarly, the grape press is usually brought outside of the winery and the work done out in the cold. To make it even more difficult, extracting the juice from the grapes takes a long time, so the whole process is one big freeze-fest!
And just what is it about this procedure that results in such a luscious wine? It's a concentration effect. Pure water will start to freeze at 0C, so if you have water with something else in it, those other things won't freeze at that temperature.
So if you take a glass of juice (Kool-Aid was one of my favourites!), put it in the freezer and wait for a while - until it's partially frozen and there's quite a bit of ice in it, take it out and pour the remaining liquid into another glass. Now you have one glass that has ice in it, and another with the juice. If you actually do this, you'll note that the ice (if you wash off any remaining juice) is clear - not coloured like the juice. What you have there is pretty much pure water, which has been frozen out of the juice. If you taste the juice in the other glass, you should notice that it's a lot sweeter, and stronger tasting than the original juice - what you have done is concentrated the juice by freezing out some of the water in it.
The making of icewine uses the same principle. As the grapes freeze, ice forms inside the berry, but all the good stuff - the sugar and flavour compounds - are concentrated. So when the grapes are pressed, a concentrated sugary syrup of juice comes out, which can have twice the concentration of the original juice (the colder it is, the more concentrated the juice). This is what helps to make the wine sweet, and also have its intense aroma and flavour.
And this is why the temperature has to be so cold, and has to stay that way. If the grapes warm up, then there is not as much ice in the berries, and the juice won't have the same amount of concentration.
There aren't too many traditional grape growing areas that have sufficiently cold temperatures consistently, enough to make ice wine. As well, the temperatures can't get too cold, or the vines will freeze and die. Vitis vinifera, which is used to make the vast majority of wine in the world, can survive to around -18C if the conditions are right. So there is a relatively small window between cold enough and "*#!#%*! The vines are dead!!"
Germany was probably the first place where ice wine was made, but the conditions for good ice wine production aren't too common. The Niagara Peninsula, between Lakes Erie and Ontario in Canada is an area that seems to get appropriate conditions pretty well every year, even if they may have to wait until February before they arrive!
Those with quick minds would probably like to point out that this is all very inconvenient, so why not pick some grapes, stick them in a freezer, and press them in there - none of this mucking about in the cold, picking grapes, at least! This technique certainly works, but there is something about having those grapes hanging out there for so long before they're picked that helps to make the wine extra-special. The Cool Climate Oenology and Viticulture Institute at Brock University has done quite a bit of research into icewine production, and they are uncovering some of the factors that affect icewine quality - one of which is likely to be "hang-time" and freeze/thaw cycles.
So how does China come into this discussion? China, as I may have mentioned in passing before, is a big place. They have a huge spread of climates within the borders, and areas suitable for ice wine production are among the country's resources.
Book now for part 2 of China - the sleeping ice wine giant...
This time, its about something that was developed in Germany, really took off in Canada, and now it looks like China is poised to take over.
Ice wine. The luscious nectar made from frozen grapes, it is highly prized by some, and highly priced by many!!
Why is it so exclusive? To make the real stuff, the grapes need to be naturally frozen, and picked when the temperature is -8C or lower, and will stay that way until all the pressing is finished (these are Canadian rules - some other countries have their own regulations, but the Canadians seem to have the most comprehensive set, designed to ensure the integrity of their icewine (all one word, as opposed to the generic "ice wine" product)). That's pretty cold, and throw in the fact that it could be windy as well, and you're looking at a temperature of -16, easy, with the wind chill!
Wouldn't it be nice to be able to sit in a mechanical harvester and collect all those grapes into a hopper? It would be nice, but you wouldn't get many grapes that way, as by that time of the year, the cluster rachis has gotten brittle, and the berries fall off far too easily! So the grapes must be hand picked! Sometimes in the dark, when it's the coldest and to ensure that the grapes do not get above -8C. Similarly, the grape press is usually brought outside of the winery and the work done out in the cold. To make it even more difficult, extracting the juice from the grapes takes a long time, so the whole process is one big freeze-fest!
And just what is it about this procedure that results in such a luscious wine? It's a concentration effect. Pure water will start to freeze at 0C, so if you have water with something else in it, those other things won't freeze at that temperature.
So if you take a glass of juice (Kool-Aid was one of my favourites!), put it in the freezer and wait for a while - until it's partially frozen and there's quite a bit of ice in it, take it out and pour the remaining liquid into another glass. Now you have one glass that has ice in it, and another with the juice. If you actually do this, you'll note that the ice (if you wash off any remaining juice) is clear - not coloured like the juice. What you have there is pretty much pure water, which has been frozen out of the juice. If you taste the juice in the other glass, you should notice that it's a lot sweeter, and stronger tasting than the original juice - what you have done is concentrated the juice by freezing out some of the water in it.
The making of icewine uses the same principle. As the grapes freeze, ice forms inside the berry, but all the good stuff - the sugar and flavour compounds - are concentrated. So when the grapes are pressed, a concentrated sugary syrup of juice comes out, which can have twice the concentration of the original juice (the colder it is, the more concentrated the juice). This is what helps to make the wine sweet, and also have its intense aroma and flavour.
And this is why the temperature has to be so cold, and has to stay that way. If the grapes warm up, then there is not as much ice in the berries, and the juice won't have the same amount of concentration.
There aren't too many traditional grape growing areas that have sufficiently cold temperatures consistently, enough to make ice wine. As well, the temperatures can't get too cold, or the vines will freeze and die. Vitis vinifera, which is used to make the vast majority of wine in the world, can survive to around -18C if the conditions are right. So there is a relatively small window between cold enough and "*#!#%*! The vines are dead!!"
Germany was probably the first place where ice wine was made, but the conditions for good ice wine production aren't too common. The Niagara Peninsula, between Lakes Erie and Ontario in Canada is an area that seems to get appropriate conditions pretty well every year, even if they may have to wait until February before they arrive!
Those with quick minds would probably like to point out that this is all very inconvenient, so why not pick some grapes, stick them in a freezer, and press them in there - none of this mucking about in the cold, picking grapes, at least! This technique certainly works, but there is something about having those grapes hanging out there for so long before they're picked that helps to make the wine extra-special. The Cool Climate Oenology and Viticulture Institute at Brock University has done quite a bit of research into icewine production, and they are uncovering some of the factors that affect icewine quality - one of which is likely to be "hang-time" and freeze/thaw cycles.
So how does China come into this discussion? China, as I may have mentioned in passing before, is a big place. They have a huge spread of climates within the borders, and areas suitable for ice wine production are among the country's resources.
Book now for part 2 of China - the sleeping ice wine giant...
No comments:
Post a Comment