Pre Mox Caused by Clonal Selection, Pick Date, Pressing Techniques and Pre-Bottling Preparations - NOT Cork . . .

WINE TALK
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That science is not at all clear at this point, since there are still many theories about the cause(s) of premox.

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I don’t think we will ever have just one cause for premox any more than there is one source of TCA. Everyone gets to make their own misteaks.
But when you combine lower SO2 additions with the misuse of the new presses and the glutathione issue there is plenty of blame to go around.

I have never blamed corks because the idea that Coche buys great corks and X buys crappy ones never flies with me. I think the first four or five bottles in a case are the canaries in the mine. That does not mean that a perfect seal would not rectify many problems here.

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Ok, how do you explain the good bottles in the case, then, Mel???

To me it’s like a plague…lots of underlying vulnerabilities…bad water, bad sex, genetics, infected blankets (Lord Jeffery Amherst)…but it’s still the plague that is the “cause” in my view. So…the question here is what is the “cause” of the bad bottles (or reason for the good ones) in a given group. That’s the cause…all the rest are just vulnerabilities…that don’t become flaws in the “good” bottles…So, the focus has to be on variables, for the “cause”.

I can’t comment on Coche…as I don’t know he’s immune…and his winemaking has always resulted in an odd, intrusive sulphury smell…to me…maybe that’s some sort of protection, IF he is immune???

I’m trying to find someone to find out when they started siliconing corks in Portugal. I know that coating process is irregular, as it was explained to me as very random.

44

I have to agree with Stuart here - the corks have to play some role in the issue as the effects seem to be random within a single case.

Question for those in the know - I’m assuming but am not certain that most white Burgs are bottled unfiltered, correct? Has that changed over the years?

Also, are dissolved oxygen levels checked at bottling - have they been or are they now? The higher the DO level, the less effective SO2 will be and the ‘faster’ the wine will show signs of oxidation - all other things equal.

Cheers.

45

Tete de Beaune:
The other bottles usually follow.
Don’t forget that in order to have a good seal you need a good cork and a good bore entry on the bottle. The bore entry should be a little bit barrel shaped and the cork should seat by expanding a bit. When I sold bottles I was advised not to sell corks…nobody to blame.

If siliconning corks was the cause, why wouldn t everyone have premox??

With Coche the reductive smells protect the wine from oxidizing.

Larry, I never generalize about Burgundians. Clearly you should not need to filter white wine if it’s dry and done with ML. I have known people who put the wine half way through ML and then filter. I cannot speak to the DO issue, but my guess is that the bigger places do this. When I sold French corkers, they did not routinely feature vacuum pumps. The wineries just stood the bottles up for a week or so and hoped for the best.

As I have said a million times, I started noticing two things in the mid 90s: new presses and lower levels of SO2. These wines were well loved by restaurants. No stink!!

46

Premox is not restricted to Chardonnay or Burgundy. We had problems with premox in Australia throughout the 90’s with Riesling and Semillon. Almost on mass the industry changed from cork to screwcap around 2002-2004. No premox problems now.

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In my experience there are some producers who have been relatively spared or who seem to have a very low incidence, such as Coche and Raveneau, and most interestingly one who used to be relatively spared and then became a poster child for premox…namely Leflaive. If one knew what changed at Domaine Leflaive over that period…in vineyard management, harvest, pressing, vinification, bottling, etc…to so dramatically change their vulnerability to premox, wouldn’t that be useful information to have in searching for the cause?

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Robert, is it not interesting to know that premox can be fixed by changing the closure?

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Jeremy,

Could this also have been due to changes in winemaking techniques at any time? Perhaps they switched from an oxidative to a more reductive style of winemaking - and perhaps their dissolved oxygen rates were lowered by making winemaking changes?

I am not saying that the closure did not ‘help’ these issues - it’s just tough to say that it ‘solved’ the issues if you don’t know what they were . . .

Cheers.

50

I don’t think so Larry. Problems went from widespread to zero.

I have never had an oxidised wine that has been sealed under screwcap and have tasted and drunk 100’s (probably thousands) of wines over the past 15 years that have been sealed under screwcap. I was speaking with James Halliday a few weeks ago and asked if he had seen many wines under screwcap that were affected by premox. He noted that he never had and he would have tasted 10’s of thousands of bottles sealed under screwcap. obviously it takes away the risk of tca too.

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Jeremy,

As you may know, I’m a big fan of screw caps, and have used.them exclusively on my wines since I started my brand back in 2006. It certainly is possible to have an oxidized wine under screw cap, but only if either the cap was not put on correctly or if slight fissures may exist in the cap itself. I’ve also had a few cases where the glass was slightly deformed and the cap did not form a perfect seal.

Cheers.

52

Hi Larry,

I applaud you for using an alternative closure in a market that hasn’t yet embraced a move away from cork yet.

I’m sure it is entirely possible for incorrect fitting of the cap but I can assure you that in a market, where 90+% of young wine sold is sealed with screwcap, it is not a problem that ever gets talked about by the trade or consumers here. I suspect the rate of occurrence is minuscule.

Best Regards
Jeremy

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There have been reports of premoxed wines under screwcap.

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Is that all you’ve got? [head-bang.gif]

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Larry, don’t know about DO levels, but a famous white-winemaker in Burgundy told me years ago that the SO2 levels in the good bottles were what they should be relative to that at bottling…and the “bad” bottles’ levels of SO2 were nonexistent. That suggests to me that the problem is a bad seal, but not that lets oxygen in, as much as it lets the protective SO2 out, causing premature oxidation in those random bottles where the corks make a poor seal…The suspected problem being that the corks are randomly rigid due to random coating with silicone, thereby preventing good seals in random cases.

57

Bottles rather than the corks might be an issue. It used to be that everyone used bottles made by Verdome, BSN or St Gobain, bottles made every day. Now you see more special bottles made in small runs. The bore entry on these bottles might be off.

If the county stops maintaining roads, and you have problems with your motor mounts, perhaps stronger shocks and tires will help but they are not the cause.

Did corks change in the mid 90s?? If so, they changed for everybody. Why wouldn t we see the same problems here??

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Mel, wouldn’t your logic hold to changes in bottles as well then?

I hear what you are saying, and I agree that the bottle and closure combo have to be in sync or there can be issues.

That said, I’m just not sure how pertinent your theory is relative to others. But heck, what do I know? :slight_smile:

59

I believe there was another thread that I’m not finding now about premox with Laroche specifically. Even a small number of instances (without much opportunity to see them) does imply that cork is not the cure.

I think a lot of the “premox” Australian producers were experiencing with cork was simply failure of the poor quality corks the industry was sending them, not premox as we know it in white Burgundy and elsewhere.

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It’s just one bottle (maybe a broken seal, although it seems unlikely), but here’s another report.

http://forums.wineloverspage.com/viewtopic.php?f=3&t=47633