Although this post does finish with a recommended wine from me, the main feature today is by our regular contributor – MidWeeker Paul.
Here he brings his scientific mind (remember his piece about health) to a question I am frequently asked.
“How will I know if a wine is off?”.
Well, Paul discusses the most likely causes (and effects) of defects in wine.
As he says, such instances are rare but it is useful to know what to expect if problems have developed.
Additional help is also available from probably the most effective wine detecting device known to mankind – the human nose.
Humans have approximately 400 types of olfactory receptors shared among around six million individual receptor cells.
But, before you think those 6 million cells make you one of nature’s aristocrats, remember that my dozy old labrador had 300 million!
In the usual way, a hyperlink and picture is provided for the actual wine selection.
Over to you, Paul
“We forget that wine is merely a pause on the journey from grape juice to vinegar; it’s a kind of arrested development!
When I have walked around modern wine making facilities ,I have usually come away impressed by the levels of hygiene and cleanliness.
In the past ,this was not always the case with some wineries located near farm animals and substandard bottling.
However, despite these mighty improvements, wine can still go off.
Nevertheless, before you blame the winemaker or retailer, consider if it could be a home grown fault.
Could you have:
- Stored the wine for too long?
- Stored it in places with big temperature fluctuations?
- Stored it where sunlight is a factor?
- Stored it in a smelly garage?
Even when none of the above apply, it is important (and fair) to distinguish between a wine that you dislike, but is not faulty, and a wine that is genuinely off.
But, how do you tell if a wine has gone off?
Let’s look at five ways that wine can go out of condition.
The most common is Cork Taint or TCA – which stands for 2,4,6-trichloroanisole.
This can form in the cork from bits of bark that are contaminated giving the wine a mouldy smell like old, wet cardboard or smelly wet dog.
About 0.5% of bottles sealed with natural cork will suffer from cork taint.
However, many producers are increasingly using TCA-resistant corks -or screwcaps, which avoid the problem all together.
Interesting that top winemaker Jean-Claude Mas has largely gone over to screw caps to avoid cork taint and any unnecessary further oxidation.
So, what about Oxidation?
Oxidation can result from poor winemaking, poor storage or because the seal (cork or screwcap) is faulty.
Too much oxygen means wines lose their edge as the fruit fades and the wine starts to feel a bit flat and stale on the palate.
If a lot of oxygen has got into the wine, the colour will start to become less bright, with red wines going slightly brown and white wines getting more yellow.
On the other hand.
Reduction happens when a wine has too little oxygen!
Sulphur dioxide is often used in winemaking to keep wine fresh and prevent oxidation.
But too little oxygen can lead to sulphur dioxide turning into hydrogen sulphide(H2S).
That is instantly recognised as the smell loved by pupil pranksters with their stink bombs releasing an unmistakable aroma of rotting eggs.
A small amount of reduction can be cured by allowing the wine to breathe, preferably by decanting and waiting for a while,
But if it still smells of boiled cabbage … the wine has gone off.
Our fourth possible cause.
Next up is Brettanomyces or Brett, which is a type of wild yeast that can appear naturally during the fermentation process.
That is especially so when wooden barrels are being used.
At small concentrations this can give wines quite a smoky character, but too much and it’s like Stinking Bishop or blue cheese and makes the wine undrinkable.
The wine maker can get away with a small amount of Brett- indeed they might claim it was deliberate.
In large concentrations, though, the wine will smell of full-on cowshed and rotting manure.
Our final villain
Lastly Volatile Acidity or VA – a tricky and divisive subject.
VA refers to fatty acids that can evaporate at normal temperatures.
Acetic acid bacteria are present on all grapes and in all wines.
They just sit and wait for oxygen which allows them to grow, multiply, metabolise and – of course -raise VA levels.
Wander amongst vines whose grapes have been damaged by birds and you will smell a vinegar (acetic acid) aroma.
Ethyl acetate can also contribute- nail varnish remover, acetone- aromas as well.
Natural wine enthusiasts seem to show a more welcoming approach to VA – perhaps because their working practices are more likely to increase VA levels.
However, some do counter this by using sulphur and nitrogen.
An expert’s view.
The respected Phillip Cox founder of the Romanian wine company Cramele Recas says that “In the short term VA can be hard to notice, but over time gets worse ( and at warm household temperatures) transforms the wine into vinegar.
That is the reason that I do not consider VA anything but a defect.”
Mercifully, these defects are the exception
Fortunately all the listed faults are quite rare these days.
However, never be afraid of asking for a second opinion in a bar or restaurant if you detect a problem.
Equally, if you think that a correctly stored wine at home has gone off, take it back to the retailer- but not empty!”
Thank you, Paul, for an excellent summary about a problem that perplexes many.
Reiterating those last points, there is no need to be loud or dogmatic if you detect a problem in a restaurant.
Simply quietly ask the staff to take a sniff. If there is any doubt, they will usually rapidly replace a faulty bottle.
Footnote.
On the subject of knowing what well made wine should be like, here is a good, text book example of cabernet sauvignon.
2022 Errázuriz Gran Reserva Cabernet Sauvignon (£11.99 at Waitrose and 13.5% abv):
This is made by a large but very talented winemaking operation and uses fruit from Chile’s Aconcagua region.
Dark in colour with a minty cabernet “nose” to greet you, it features intense cherry, raspberry and damson flavours.
These are accompanied by firm tannin, a long smooth finish, an edge of sweetness and suggestions of violets, cedar, mocha and baking spice.
NB: Feature picture is a photo by D A V I D S O N L U N A on Unsplash
Tune in again on Monday when value at budget price points is, once more, the theme of my latest Top Tips post.
17 responses
An excellent and enjoyable read this morning. Thanks for that Paul and Brian. Have to agreee that the Cab Sav mentioned is a great wine example I’ve found all from Errazuriz solid over the years.
Agreed – and the chardonnay reviewed a week or two back is a good example too.
Great information Paul. Thanks for sharing. My problem is being the only wine drinker in my family, I can’t get through the bottle quickly enough and it seems like false economy to buy the smaller bottles.
Hi Brenda, the 750ml bottle, although the universal standard, is really not a convenient size for many people.
The wine range available in quarter, half bottles and cans, is very limited, and, as you say, not cost effective.
I have a number of empty screw cap quarter and half bottles, washed out after use. Practically every standard bottle of wine I now open, I immediately decant some out into these bottles – right to the brim and put screw cap on. I find they keep very well for at least a couple of weeks. You could decant into 3 quarter bottles, and have 4 separate helpings – or just into another half for 2 double glass servings – or whatever option suits you best. I find our weekday supper wine consumption has stabilised to a half bottle equivalent between us, and we often have 2 quarter bottles, say, a red and white, at a meal. It works really well for us, and for a number of single wine drinker households who have adopted the strategy!
Hello Brenda,
Richard has made some excellent suggestions .
I am conducting extensive research – ahem!- into half bottles and in particular finding good ones that are close to half the cost of a full bottle.
I hope to write something on it later this year and call it “The Joys of the Half Bottle”.Catchy?
Short notice on a not for long offer that finishes at Tesco on Monday 24th … 25% off buy 6. Some decent double dips with our Tesco Clubcards … Mucho Mas down to under £6 and over £4 off Villa Maria Sauvignon Blanc . That Prima Luna Frascati Brian will be well cheap!!
Thanks for the details of that multi-buy.
Asda are doing a 25% off three bottles of selected extra special wines.
I picked up their excellent Gavi de Gavi on Rollback and offer reduction to £7.06 and their very good party fizz Cremant d’Alsace at £7.02 which is the lowest price for it I have ever seen.
Other good choices would be their Dâo red and Pinot Grigio Trentino.Ker-Ching!
As I said to Eddie., these are really helpful reminders as I do not always get notifications of these short notice promotions.
Without the ‘25% off 3’ offer the Asda Crémsnt d’Aksace is £9.36. By way of comparison I see the new rebranded / new label Crémant d’Alsace at Waitrose just released, made by the Cave de Turckheim is on ‘introductory offer’ until 15 April for £10. Worth a comparative tasting?
Methinks there is some skulduggery at play here! Surely we should compare the two Crémants at their offer prices?
I do hope Keith you are not the kind of gentleman to turn after only eight paces and discharge the cork early!?!
Perhaps we need a trusted referee?Mmmm…
Paul, I get your point but at the same time is this not falling into the trap of assuming a more expensive wine will be ‘better’ (however you judge that) than a cheaper one, and vice versa? Surely some of the gems identified by Brian on the MWW website convincingly demonstrate this not to be the case? But, for the record, I was merely thinking aloud whether there was any discernible differences between these 2 supermarket Alsace crémants were I to visit each of the retailers’ outlets in town this weekend to pick up single bottles
In response to Brenda’s issue, I am generally a solo drinker, particularly when it’s red and my answer is to bang the cork / screwcap back in / on and stick it in the fridge straight away. I often enjoy a bottle over a week or so. It is just a matter of remembering to take the red out of the fridge, or better still, pour a glass, in good time. I rarely detect any deteriation and wines often improve over a few days.
Yes Edwin that’s what I do too!
Always presuming we are both dealing with bottles that are not in the ”fine wine” classification, £6 to £12, they are the kind of cheaper-end agricultural product that firstly don’t require so much mollycoddling and we chuck them in the fridge to preserve something of their quality. And it works .. even for several days, especially white wine . But maybe it goes a tad too far the wrong way. Use it for cooking eh?
“Put it in the fridge” is always good advice when it comes to preserving things. As you imply, do it as soon after opening the bottle as possible.
What a fascinating article. I recently opened a bottle of Rioja bought in the last £10 fine wine offer in Waitrose. It was very odd; not corked, not vinegar but “a bit flat and stale on the palate”. Thank you Paul, I can now describe the issue much more clearly thanks to your article.
Really good to hear from you Nichola and welcome to the Comments section. That is the great things about descriptions like those Paul has crafted – they do allow you pinpoint the problem with a wine better. Sounds a bit like an age issue with that wine (rather than a defect) and I am seeing a lot more of that at the moment – but it may just be that we are between vintages. Previous ones getting tired but next ones not ready yet.