cryoextraction

[schneich]

hi folks,

a few days ago, after attending the wineweek (one of the biggest white wine events for rheingau, mosel, saar-ruwer regions in cologne) i had a weird idea.

after tasting a lot of eiswein and trockenbeerenauslese i talked to the winemakers about the eiswein making process. the thing they do is pretty much to leave some grapes on the wine until the first subzero freezing night. that night they pick the hardfrozen grapes and press them in frozen state. what happens is that the sugary concentrate inside the grapes that doesnt freeze well, gets extracted and leaves behind just skins and frozen water aka ice, hence the name :-)

the stuff that leaves the press is a golden very sweet and intense syrupy juice.

my idea is that this could be a very nice method to concentrate pretty much every sweet fruit, without changing (and killing) the flavor trough cooking. it could ba as simple as freezing some strawberries and pressing them in a winepressing device like this

i havent got such a thing yet, but iam hoping to get a hold of one soon

what do you guys think ??

cheers

torsten s.

[Shalmanese]

When I was small, we used to freeze fruit juice in special molds that would turn them into iced lollys. The water freezes but the sugar solution stays liquid. If you suck really hard on them, all the flavour gets sucked out and your left with essentially pure ice.

It's certainly a low-tech way of doing it but I imagine children have been doing this since refridgeration was invented.

[scott123]

Sugar is a freezing point depressor. Grapes work well becuase of their high sugar content. Strawberries, on the other hand, have very little sugar, and thus wouldn't work all that well.

[akwa]

yes should work and is a great idea

but you need maximum extraction

and this has been difficult for me to obtain while keeping the product cold

it also works to freeze fruit purees and hang them in the refrigerator, as the higher sugar liquid passes through first

[akwa]

ps interestingly the chinese use a technique for green vegetables (i saw from cheong liew and then tim pak poy in australia) to wok cook from frozen, therefore the water is essentialy steamed out before the vegetables over cook, therefore staying green and crispy in very short time

losing all that foul vegetable water

[andiesenji]

I read an article several years ago about one of the makers of flavored syrups that froze very mature fruits and then spun out the mashed, frozen stuff in a large centrifuge that extracted the concentrated flavored liquid from the pulp and skins with much of the water ice remaining in the pulp.

As I recall, the fruit mentioned was black currant so it was probably a European company.