Thursday, June 21, 2007

Beware Sancerre wine bottled "sans care"




Updated Saturday 24 June (please scroll to end)

Updated Saturday 23 June (please scroll to end)

Up until two days ago, I had always regarded Sancerre a safe wine for entertaining. Everyone knows the name, and this occasional tippler considers the rosé to be well balanced (usually) between sweetness and acidity, without the harsh resinous edge one associates with a lot of much cheaper offerings.


We've had a Sancerre rosé sitting in the rack since last November (about which more later) and decided on Tuesday that we would have it between ourselves.

I'm glad we made that decision, rather than offer it to guests. It was dreadful. After a glass each we gave up in disgust. Thirty minutes later, we both had a metallic burning taste on the palate. It stayed for several hours: had we been entertaining guests, it would have ruined the evening.


One sniff at the neck of the bottle confirmed my suspicions - sulphur dioxide ! The wine had been heavily overtreated with sodium metabisulphite.

(For the chemically uninitiated, metabisulphite comes as a crystalline white solid. It slowly releases its sulphur dioxide in contact with water: anyone who has made their own wine will be familiar with it as Campden tablets).


So where did we get our duff Sancerre, you may be wondering. At some dodgy back street supplier, or from the pile-em-high, sell-'em cheap basket at the supermarket ?


Far from it. It was a trophy we brought back from the Salon du Palais Gourmand at the Cagnes race course, the subject of an earlier post.





The lady had offered a sample at one of the stalls as we passed, and we had liked it. She wanted us to buy a crate, but I politely declined, offering instead to buy the opened bottle at the full price, so we could polish it off at home that evening.

But no, the lady would not hear of that, and produced an unopened bottle of 2004 Sancerre for about €15 as I recall.

So how come it had so much sulphur dioxide, and was there any way we could have known ?




Well, this retired biochemist/food scientist is no innocent abroad when it comes to food additives. Yes, I had noticed the warning in small print on the side of the bottle "contains sulphites". You can see it (just) in the pictutre above, written vertically on the right of the label.
The principle of adding a little sulphite to wine is not in question. Without it, the wine would go off very quickly. Enough oxygen can penetrate even the best cork and cause premature oxidation and spoilage of the wine, turning it to vinegar.

The problem is a quantitative one. Under EU regulations, the label "contains sulphites" is required for levels of sulphur dioxide in excess of 10 mg/litre.
That's just below the level at which most people can detect its presence. Wine becomes unpleasant when the level is about 20-30 mg sulphur dioxide per litre.
Now here's the sting in the tail, which frankly I find unbelievable: the EU allows a level of sulphur dioxide in white wine or rosé of up to 210 mg/litre. Yes, you read that correctly: it's perfectly legal to sell wine that has 7 to 10 times the level that gives wine an unpleasant smell or taste!

So when you buy a bottle of wine with that warning "contains sulphites" you have no way of knowing whether it has 11mg per litre or 210 mg per litre. What kind of idiocy is this ?

In fact, it's not just flavour that is an issue - there are health implications too.

The World Health Organisation recommends a maximum daily intake of 0.7 mg of sulphur dioxide per kilogram of bodyweight.

For a man of average weight this is less than a third of a bottle of a white wine with a concentration of 200 mg per litre.

Regular consumption of conventional wines means regularly exceeding the RDA of sulphur dioxide by a large margin.

More specifically, sulphur dioxide can cause allergic reactions in some people. It is dangerous for asthmatics even at very low levels.
The warning on wine "contains sulphites" is well nigh useless. It puts one in mind of those words "this product may contain traces of nuts", which are inserted purely to protect against lawsuits from people deemed to have rare allergies. Irrespective, it reflects poorly on the EU's consumer protection that French and other EU wine producers can legitimately sell wine that is either undrinkable, a health hazard, or both.
For this and because of some other bad experiences, I have adopted a simple solution. I no longer spend more than 5 (or at most 10) euros on a bottle of wine. If it doesn't taste right, it goes down the drain, and I try another bottle !

PS: I've used the British spelling for sulphur and sulphites. There is now, I read somehere, agreement in the scientific community to standardise on the American spelling (sulfur/sulfites) but for some of us, at any rate, old habits die hard.
Update Saturday 23rd June
I am presently doing internet searches on preservatives in white, rosé and red wines. There's an awful lot of dross, some quite poetic, but dross all the same. Just once in a while, one chances on something that is illumintaed with a little hard science.
Here's a link I would recommend:
http://www.wineint.com/story.asp?storycode=1810

It's an article written by one Jamie Goode PhD, who has his own site ( which I yet to visit!)

http://www.wineanorak.com/

What caught my eye was the following statement:
Sulphur dioxide's main role is binding up the aldehyde formed, so that we don’t smell the oxidation product’.
Well, well. After trawling through page after page about sulphur dioxide acting as an antiseptic in the early stages of winemaking, and as an antioxidant in the cask or bottle, here we get a totally different view of it acting to mask an alleged off-flavour.
Alcohol is converted by bacteria first to acetaldehyde (aka ethanal), and then to acetic acid (aka ethanoic acid, "vinegar")
CH3 CH2OH -> CH3 CHO -> CH3COOH
According to Goode, the real purpose of sulphur dioxide is to react with acetaldehyde, present from prior oxidation, converting it to a (presumably) tasteless compound.
(The reaction between aldehydes and sulphur dioxide is in fact standard A-Level chemistry).
If that is so, I find it appalling that a smelly, toxic chemically-reactive substance, sulphur dioxide, one that is a recognized hazard to asthmatics, and perhaps other susceptible individuals, is being used simply to mask another flavour. What is particularly absurd is that makers of certain sherries and madeira wines encourage the production of some acetaldehyde in order to impart what has been described as the flavour of freshly-cut apple.
It sometimes takes days or weeks of of patient reading to get to the real truth behind the use of certain traditional processes that would probably never have been approved if discovered yesterday. Thus speaks the retired Head of Nutrition and Food Safety for a major industry research association. I shall continue to scour the literature to see what else might be lurking there that needs to be brought to public attention.
Update: Sunday 24 June
Have just this minute posted the following to Sally Peck's Telly current blog post entitled "Who makes the best wine?"
An excess of sulphur can ruin any wine

Colin Berry 24 Jun 2007 14:12

A French wine-producing chateau, or its equivalents elsewhere, may produce the finest wine of its type in the world. But all that is irrelevant if the wine is sent out with an overdose of chemical preservative.
Many red wines are preserved naturally to some extent by their own grape tannins, but in white and rosé wines, where tannins are absent or lacking, there's the age-old tradition of adding sulphur, in the form of potassium metabisulphite.
It's usually claimed to protect wine against bacteria/wild-yeasts prior to fermentation, or against chemical oxidation afterwards (although some industry insiders say it's real purpose is to mop up aldehydes, preventing a certain flavour, but that's perhaps controversial) .
Irrespective, neither the principle nor practice of adding a little sulphur is being challenged here, provided it's not overdone. Most folk can't detect the sulphur dioxide at levels below about 20 to 30 mg/litre.
The problem is that many wine producers appear to be adding add extra sulphur dioxide just for luck, and can get away with this, thanks to lax labelling regulations. I've just had to throw away half a bottle of 2004 Sancerre, bought at a French food exhibition, on account of excess sulphur dioxide.
If you look carefully at most bottles of wine, you will find in tiny letters the words "contains sulphites". All that indicates is that the wine contains 10mg/litre of more of sulphur dioxide, which in practice includes virtually all wine. But the wine can legally contain up to 210mg/litre of added sulphur dioxide quite legally, in the EU, making it undrinkable, and a health hazard, at least to asthmatics.
Until this labelling nonsense is sorted, and wine is labelled so that consumers know what they are buying, then comparisons between French and other wines are futile.
A wine that is over-dosed with sulphur dioxide can leave a metallic or burning sensation on the palate that can totally ruin a meal. Why do we, or the French for that matter, tolerate this state of affairs ?
I for one will stick to vin ordinaire until this is sorted. Then, if it does not taste right, it will go straight down the drain, and I'm not too much out of pocket if I have to open a second bottle."

8 comments:

Gigi said...

I'm no wine expert - just a happy, sometimes very happy, consumer. I can't afford expensive wine but I sometimes wonder if it's really an indication of quality. I recently bought a cheap vin de pays from the foire at Mens and it was quite delicious; then I bought a burgundy for 9 euros (expensive for me) and it tasted like paint stripper.

I do like chilled rosé in the summer but the only one I've ever enjoyed is Bandol. I bought a Tavel the other day and I was really disappointed.

ColinB said...

Hiya Gigi

Like you, I find buying wine a complete lottery, with price being a poor guide to quality.

I was interested in your comment on a recent Colin Randall thread, to the effect that it's rosé that gives you a headache, and not red wine.

That's contrary to the usual received wisdom that red wine, with all its histamine and tannins is the one that we're supposed to avoid.

I can't help but wonder if you're not allergic to sulphites. They are usually at a much lower level in red wine, which is largely preserved by its own tannins, but as I've indicated, they can be in white and rosé wines, sometimes at unnecessarily high levels - up to 210mg/liter being legal.

Do you find other sulphite-rich foods give you a headache, eg dried fruits such as raisons, apricots etc, or supermarket prepared salads, oven-ready chips etc ?

My wife always knows when I've overindulged in white or rosé wine. I don't beat her, or see pink elephants - I get coughing fits, as if I've got bronchitis. There's a real scandal here - but it's never addressed because sulphur dioxide has been used for centuries as a wine preservative, so it "has to be safe".

Gigi said...

That's interesting, Colin. White wine gives me a headache too. I do eat dried apricots from time to time but if I got a headache afterwards, I don't think I would have made the connection.

I'll do an experiment. I'll over-indulge in dried fruits and see what happens. Won't be as fun as over-indulging in rosé, of course, but as I'm doing it in the name of science, I'll make the sacrifice...

I'll let you know...:-)

Peter May - The Pinotage Club said...

I no longer spend more than 5 (or at most 10) euros on a bottle of wine - I find it amazing that your response to buying a badly made bottle of wine (not from a reputable shop but from a show stall) is to buy only the cheapest wines in future. Surely the opposite makes more sense.

All the wines you have ever drunk have contained sulphites. You may like also to add this to your reading list -- http://waterhouse.ucdavis.edu/winecomp/so2.htm

ColinB said...

You have totally missed the point, Peter.

Of course all wines contain sulphites. But as I've said already, the declaration "contains sulphites" is deliberately vague because the wine could contain anything between 10 and 210mg/litre.

Where is the guarantee that an expensive bottle of wine would never contain more than 20-30 mg/litre, the level at which sulphites become not just detectable, but make the wine unpleasant ?

Of course there is no such guarantee, as you know full well.

Your post comes across as nothing more than a pretentious special plea by a wine merchant, or someone else with a financial interest in this deception.

This site is about the facts, the scientific facts, not about pulling wool over peoples' eyes.
There's been too much of that already, for far too long.
The pretence that the more expensive the wine, the more acceptable it will be, is just that - a pretence.

There are too many "experts" who seem unable to recognise the damage that can be done to a wine, however good, by an overdose of chemicals.

Peter May - The Pinotage Club said...

I don't think I have missed the point. The point is that all wines have sulphites and always have. It is just since the change in EU labelling regulations that came into force last year that required the 'contains sulphites' that all of a sudden people have started blaming them for all sorts of bad things.

I personally think that you tend to get what you pay for and that better wines made with more care will - must - cost more, but if you want to buy the cheapest go ahead. Pay £4.25 for a bottle of wine and you are going to get about 30p worth of wine after taxes and fixed costs are taken out. Pay £8 and most of that additional 4 pounds go to the value of the wine.

I agree with you that the 'contains sulphites' message is meaningless, but I am happy with the legal limits and in decades of drinking can't recall more than a couple of wines that may have been over-sulphured.

I have no financial interest in selling wine.

ColinB said...

When I was living in Britain, I would have concurred wholeheartedly
about the false economy of buying cheap wine.

But I live in France, where the taxes are much lower, and have had perfectly acceptable wines for everyday consumption for less than €5 a time.

It's a case now of once bitten, twice shy. I was frankly outraged to buy Sancerre that was undrinkable. It was through internet research that I discovered the idiotic labelling, which is on a par with "this product may contain traces of nuts" - in other words, it's nothing to do with protecting the consumer, and everything to do with protecting the producer from legal action.

Until the wine producers and distributors put their house in order, and begin to show the level of sulphites more informatively, eg less than 30mg/litre, less than 150 mg/litre etc, then I for one will not be squandering my modest and hard-earned pension on over-sulphited wine.

I suspect there's some laziness and lax practice here - just toss in a extra pinch of bisulphite as an insurance policy against faults in production or storage. That's simply not good enough. Sulphur dioxide may have been used for centuries, but it's still a toxic chemical, and we now know a lot more about its toxicity than the Greeks or Romans did when they first hit on the idea of burning a few sulphur candles near their vats of wine.

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