Three Questions About French & Australian Riesling

"Raymond" skrev i melding news:d0cf0v$mg6$ snipped-for-privacy@reader01.singnet.com.sg...

Given that they use to be bone-dry and have about 13+%abv they probably are harvested at about 100-110 degrees Oechsle, which is Auslese level. (24-25 Brix for you in the U.S.)

Probably not, i.e. I don't think they have to - it is not all that high.

Fashion - a high sugar consumption is today seen as a characteristic of uneducated people and who wants to be stigmatized like that? :-) Anders

Yes, but that doesn't necessarily mean that it isn't practiced.

Can that be true? Sugar more expensive than RO? I have no particular objection to RO, but it is my understanding that it is an expensive process.

Andy

True, but like I said, there are better ways of cheating...

Apparently not, otherwise you would not have over 600 of these things in France's top two wine areas.

Mike Tommasi, Six Fours, France email link

snip

Chaptalisation is forbidden in Australia. See

Chaptalization is not allowed in Australia

compared

I understand reverse osmosis is used more than most winemakers are willing to admit, and that it is usually used to remove volatile acidity, or to decrease alcohol concentration to below 14 percent for tax purposes. In America, that is -- Europe may be different. Can it also be used to increase alcohol?

Andy

It is.

Yes. Reverse osmosis ("le concentrateur") removes water either from the must (legal there, where chaptalisation is permitted) or from wine (illegal).

Either process increases the alcohol content of the finished product.

M.

It is.

Yes. Reverse osmosis ("le concentrateur") removes water either from the must (legal where chaptalisation is permitted) or from wine (illegal).

Either process increases the alcohol content of the finished product.

M.

Ooops, sorry Martin. Now chips, are they OK?

Mike Tommasi, Six Fours, France email link

Salut/Hi Andy,

le/on 5 Mar 2005 18:04:18 -0800, tu disais/you said:-

I don't know whether 600 machines in the thousands of estates counts as a significant but I do know that their usage is "tolerated" not encouraged. However, in a year where rain during harvest has diluted the crop, and where otherwise chaptalisation would have to be practiced to increase the alcohol level, I can understand the temptation.

Grinm. All sorts of things are done mucxh more than most winemakers are willing to admit!!!

concentration to below 14 percent for

Really? This is an entirely different usage from that practiced here, and I'm not clear how this can be done. Sounds like a question for Mark!!!

Trying to keep technicalities to a minimum, reverse osmosis is like operating a filter. You take a semi permeable membrane, which lets small molecules through but not larger ones, and force the liquid being treated through it. It's most common usage is for desalination, where it allows H2O through but not Na+ and Cl-. I would be utterly astonished if a "normal" semi permeable membrane could allow volatile acidity (acetic acid CH3C00H) and alcohol (ethanol, C2H5OH) through _without_ letting through the water in much larger quantities. I have given the chemical formulae, because in general the more complex the structure (and the higher the atomic weight of the elements composing the molecule) the larger it is, and the more difficult it will be to pass them through the pores of the filter. Now it's obvious that these two chemicals with two carbon atoms each will be bigger than water with only one oxygen atom. So forgive me if I am doubtful about whether you're right.

Indeed it can, or rather, it can be used to _remove water_, which is slightly different in essence, and why it could be considered a "better" solution to difficult years than chaptalisation.

Think about it. Adding sugar does nothing but adding alcohol. It can easily throw the wine out of balance as it won't increase any of the components of flavour.

Removing part of the water simply makes a more concentrated wine, almost as if the vines had received less water in the run up to harvest. Before everyone (and Mike T especially) jumps on me for this, I hasten to add that it's not going to give results that are always better. BUT, as I said at the beginning, in years where the harvest has been diluted by rain during picking, it could very well play a part. I'm thinking of the notorious '64 vintage in Bordeaux. This was a year where some Chateaux were able to complete their pickings in dry conditions and made magnificent wines. Others were caught by the rain, the must was diluted and the wines were not so good. Some tried to over-chaptalise their way out of it, and gave "hot" wines. Others simply had dilute wines. If they had had R.O, it is very probable that they would have been able to make a better tasting wine.

Note that I'm not expressing an opinion as to whether it's a "good thing" or not, I'm simply trying to explain how R.O. works and therefore what it can and can't do.

I guess you're on right side, Ian. I have never ever heard of VA being removed by inverse osmosis. Diminishing alcohol levels (up to

There was quite a good article in the Wine Spectator archive, but I don't use their archives anymore since they ask $$$ for it.

M.

particular

expensive

encouraged.

Ian, During my visit to Bordeaux last year, virtually every Chateau that we visited, Margaux, Mouton, both Pichons, Lynch Bages, Cos d'Estornel, Pavie, Mondotte, etc. were quite vocal about the use of RO, concentrators, rotogravure (sp), micro-oxygenation, and all sorts of techniques to get more concentration, higher alcohol and softer tannins from their wines. Basically they shrugged (the French shrug) and said "it is what the market wants so that is what we give". Given all of the agricultral regulations they felt that technology gave them the tools that they needed to compete. They also felt that the higher alcohol levels gave a richer mouthfeel and a bigger flavor to the wines. While all declined comment on pricing they all recognized that in order to compete in a world market that things had to change and most conversations started and ended with the French shrug. For the uninitiated the French shrug is a body movement where the shoulders move upwards towards the ears while the head moves down into the shoulders. This is accompanied by a palms up gesture, a slight rolling of the eyes to the side and a slight exhale through pursed lips prducing a soft "puh" sound. I found it to be fairly universal in France and is used to start and end many conversations...:-) "puh"

concentration to below 14 percent for

Err... It is?? I'd imagine that Andy is thinking of another type of concentrator, the name of which escapes me, that works by evaporation. Since VA is by its nature volatile, you are essentially distilling it out of solution, though by all rights you'd also lose alcohol.

RO is basically dialysis run under pressure, so it uses exclusion based on molecular size primarily, as you've so ably described.

Mark Lipton

Hi Mike - Oak chips are used - usually in high volume el cheapo reds. Isinglass - (boiled down sturgeon bladders from memory) is also used in fining wine. So imagine, in one bottle you can have fish and chips and a sprinkling of vinegar (in wine jargon - volatile acidity measured as acetic acid).

Cheers! Martin

PS - I prefer my reds unfiltered unfined and unsophisticated.

Thanks, Ian, for your thorough response. Look here for an explanation of how RO is used to remove VA. (Even more interesting, how it was used in Australia to remove smoke taint from wine made from grapes that were exposed to wild fires.) For the moment, I too am not judging the ethics of using RO.

Andy "Keeping an Open Mind" Thomas

Salut/Hi Andy,

le/on 5 Mar 2005 18:04:18 -0800, tu disais/you said:-

I've just noticed your email address.

What a shame I didn't know you were in Walla-Walla, as Jacquie and I were there last fall, and we'd have loved to meet you there. We had a great trip, spending 3/4 nights in the area, and visiting a bunch of wineries. MOST impressed with them in general and even managed to relate to the amazing Charles! However, the place that we most enjoyed visiting, I guess, was the Woodward Canyon Winery where Rick's enthusiasm really set up alight. We'd allowed loads of time for the visit, and were late arriving next door at l'Ecole 42!!!

by the way, you'll perhaps have seen my comments and others' amplifications. I wonder if you might not have mistaken the name/purpose of the machine.

LOL !!! Do you wrap it in gresaproof paper before drinking?

Right you are. Unfortunately it seems that most of the wine from Australia that is seen as competing with EU wine here is the kind of cheap overoaked stuff that you are describing.

A friend of mine, young chap finished winemaking school in Dijon and who did a year in Australia, was telling me that somehow all the rules there are different somehow, you can make great wines at 2-3 times the yields that would produce dilute piss here in Europe, while you get deep concentrated perfect grapes. It cannot be only a matter of insolation (where I am we get 3000 hours of sun per year, yet high yields will ruin our mourvedre).

Someday I'll have to come and take a look...

Mike Tommasi, Six Fours, France email link