Category: General

Georgian wine PDOs

Just a quick post to remind you of my Georgian PDO mini-series, and also help you get a better overview of it – something otherwise hampered by the reverse-chronological order on my home page.

My first post aims to give a quick practical guide to the Georgian PDOs you are most likely to come across in the UK – Tsinandali, Mukuzani, Kindzmarauli and Khvanchkara . Arguably, these are also the most important PDOs in general. In outline at least, this covers pretty much everything that most wine drinkers will need to know about Georgian PDOs, while the other two posts in the series are more hardcore.

After the practical guide, I dive into more detail, listing and summarising all the current PDOs, and giving a bit of background. Here I try to stick to the facts.

Finally, I express opinions about the Georgian PDO system and labelling requirements, and offer a few suggestions for improvement.

Georgian wine PDOs – an opinion, with suggestions

I understand absolutely why Georgia feels the need to try to protect names in its own country, and perhaps even more importantly in Russia, which has a bit of a history in wines fraud and is still an important market. I also think, when selling to foreign markets where Georgian wines are less understood, including the UK and the EU, it is a good idea to have a solid PDO system in place before it is absolutely necessary. And it is probably a shrewd move to make that system compatible with the EU’s.

The legal framework for Georgia’s PDO system looks sound to me. I won’t bore you more than necessary, but there is a law that bans the misleading use of PDO names on labels, and in advertising and related documents. It does leave open the question as to what could be construed as misleading, but is otherwise clear.

Additionally, each PDO registration document carries a paragraph that says how, for foreign language labels etc, the PDO name should be spelled using the Latin and Cyrillic alphabets, and that is should be followed by “Protected Designation of Origin” and/or “PDO” (in English) or the Cyrillic alphabet equivalent (presumably in Russian). The main point of these paragraphs seems to be the spelling of the PDO name, rather the circumstances in which it should be followed by “Protected Designation of Origin” and/or “PDO”. The lack of clarity is not helped by the very different ways that this clause is rendered into English in the official translation of each PDO registration document; the Georgian versions of the same documents seem to be much more consistent.

Sadly, I think the lack of clarity on labelling requirements has opened to way to some confusion. Here are a few examples of wine labels, which incidentally are not at all meant as criticism of the particular producers concerned.

On the left we have a Pheasant’s Tears Saperavi wine, with Kakheti at the bottom of its label. Is this just saying that it’s grown and made in Kakheti, or is it claiming the PDO of Kakheti? If it is the former, does that make it misleading? Then the middle label also has Kakheti at the bottom, but this cannot be Kakheti PDO because the wine contains many non-compliant grape varieties. Is that misleading? Finally, the one on the right has Kartli at the bottom of the label, which is not a PDO, so that is fine. But that does suggest the two other labels do not represent PDO claims either.

Moving on to another set of labels, the above Teliani Valley one actually has three PDO names on it: Teliani, Tsinandali and Kakheti. I think most people familiar with Georgian wines would assume that it is Tsinandali PDO. But is that actually correct? And what are other people to think? Teliani Valley is actually a producer’s name but it looks geographical, and Kakheti would be more recognisable for someone who knows Georgian regions but not wine. And for those smarty-pants who thought the Teliani Valley wine was Tsinandali PDO, what about the label on the right. Tsinandali too? Nope, I don’t think so – look more carefully – in smaller letters it says Kakheti AOC. To be fair, I think this is an old label, which is also indicated by the use of AOC rather than PDO, but at the very least this is very confusing.

Actually, it is quite common for Georgian producer names to include the name of a PDO. Apart from Teliani Valley, examples that spring to mind are Tsinandali Estate, Vazisubani Estate and Royal Khvanchkara. OK, it happens in other countries too, but that does not make it any less confusing.

To be constructive, and with all due humility and the perspective of a foreign drinker of Georgian wines, I would suggest a couple of additional PDO labelling regulations:

1) PDO wines should have the PDO name clearly displayed on the label, followed by “Protected Designation of Origin” or “PDO”. This is not unusual for other countries with PDO and PDO-like systems. In some cases  there is also some uncertainty about, or discrepancy between, the name of the PDO and what should appear on the label (Ateni, I am looking at you). Why not make it crystal clear and consistent?

2) Also, any other word on the label that is a PDO, but not the wine’s actual PDO, should have a clearly defined context.  So, for example, a Tsinandali PDO wine may additionally say “Wine of Kakheti”; Kakheti PDO wines may say “Made from grapes harvested near the village of Tsinandali” on the back label (if that is true, of course); and producer names that incorporate a PDO name should usually be preceded by “Produced by”.

Additionally, moving away from the subject of PDOs, it might be worth seeking to protect the use of “qvevri wine” on wine labels, restricting its usage to defined production methods – I would suggest limiting it to methods that are traditional in the region of origin. Also, it would not hurt to standardise on “qvevri” or “kvevri” as the transliteration for wine labels. By all means, avoid the mess that Armenia got into with “karas” and “karasi”.

Is all this really so important? Well, it’s hardly a life or death issue, but I believe clarity is the key to communicate Georgian PDOs to wine-drinkers, especially in markets where the wines are little known. It is effectively a type of branding – one that deserves care and attention over a long period of time.

Georgian wine PDOs – the details

I will explain in this post some of the formal details of what Georgian wine PDOs are all about, and how to get further information about each of them, but firstly here is a summary table of the 25 wine PDOs currently registered. (The table will probably display better on phones if your screen is horizontal.)

PDO name Region Style Grape varieties
Akhasheni Kakheti Semi-sweet red Saperavi, Saperavi Budeshuri
Akhmeta Kakheti Dry, semi-dry or semi-sweet white; or amber Kakhuri Mtsvane, and (for amber wine only) ≤15% Kisi and Khikhvi
Akhoebi Kakheti Dry red Saperavi, Saperavi Budeshuri
Asuretuli Shala Kvemo Kartli Dry red Asuretuli Shavi, ≤15% Takveri and Shavkapito
Ateni Shida Kartli Sparkling or slightly sparkling white; or dry non-sparkling white Chinuri, Goruli Mtsvane, Aligoté
Bolnisi Kvemo Kartli Dry, white, amber, rosé or red Rkatsiteli, Chinuri, Goruli Mtsvane, Saperavi, Tavkveri, Shavkapito, Asuretuli Shavi
Gurjaani Kakheti Dry white Rkatsiteli and ≤15% Kakhuri Mtsvane
Kakheti Kakheti Any sweetness level, and any colour Rkatsiteli, Kakhuri Mtsvane, Kisi, Khikhvi, Mtsvivani Kakhuri, Chitistvala, Saperavi, Saperavi Budeshuri, Cabernet Sauvignon, Rkatsiteli Vardisperi
Kardenakhi Kakheti Dry amber; or medium-dry fortified white Rkatsiteli, and ≤15% Kakhuri Mtsvane and Khikhvi
Khvanchkara Racha Semi-sweet red Aleksandrouli, Mujuretuli
Kindzmarauli Kakheti Semi-sweet red Saperavi, Saperavi Budeshuri
Kisi Magraani Kakheti Dry white; or dry amber Kisi
Kotekhi Kakheti Dry red; or dry white Saperavi; or Rkatsiteli
Kvareli Kakheti Dry red Saperavi
Manavi Kakheti Dry White Kakhuri Mtsvane
Mukuzani Kakheti Dry red Saperavi, Saperavi Budeshuri
Napareuli Kakheti Dry red; or dry white Saperavi, Saperavi Budeshuri; or Rkatsiteli and ≤15% Kakhuri Mtsvane
Okami Shida Kartli Dry red; or dry white Shavkapito; or Chinuri and/or Goruli Mtsvane
Okureshis Usakhelouri Lechkhumi Red. Dry, semi-dry, or semi-sweet Usakhelouri
Salkhino Ojaleshi Samegrelo Dry red Ojaleshi
Saperavi Khashmi Kakheti Dry red Saperavi
Sviri Imereti Dry white Tsolikouri, Tsitska, Krakhuna
Teliani Kakheti Dry red Cabernet Sauvignon
Tibaani Kakheti Dry amber Rkatsiteli, and ≤15% Kakhuri Mtsvane and Khikhvi
Tsarapi Kakheti Dry amber Rkatsiteli, and ≤15% Kakhuri Mtsvane and Khikhvi
Tsinandali Kakheti Dry white Rkatsiteli and ≤15% Kakhuri Mtsvane
Tvishi Lechkhumi Semi-sweet white Tsolikouri
Vazisubani Kakheti Dry white Rkatsiteli and ≤15% Kakhuri Mtsvane
Zegaani Kakheti Dry red. Bio. Qvevri Saperavi

The links in the table take you to the official English translations of the Sakpatenti PDO registration documents, which include quite a lot of detail, including maps. I recently printed them to PDF files, because I could find no other way of linking to the individual PDO documents – this means that they will not necessarily be the latest versions, so check the registration and printing dates in the PDF files if in doubt.

There are issues with the Sakpatenti English translations. In particular, note that the Georgian originals consistently say “up to 15%” when specifying a grape variety percentage, but in the English translation this becomes “about 15%”.  More on Sakpatenti and its website later.

Note also that in some places the information in my table differ may differ from other published summaries of the PDO. The obvious example is the entry for Kakheti, for which the PDO rules changed at some point. I do not remember the change being announced, but in 2010 it was a PDO for dry white wines only; now it is a lot broader. I am not sure about the reason for all the discrepancies, but I believe my version to be correct at the time of writing.

Anyway, now for a bit of background, and how to get further information…

While Georgia is not part of the EU, it has an equivalent system to regulate and protect its wines, and has chosen to use EU terminology. So initially, back in 2005, it called the protected categories Appellations of Origin. Now they are Protected Designations of Origin, though you will still see the older term in some official contexts. Incidentally, following usage in the EU, Georgia also has PDOs for goods other than wine. Additionally, there is protection through Geographical Indications for other goods, but currently not for wine.

Sakpatenti, the National Intellectual Property Center of Georgia, is the body responsible for registering PDOs, and applications for new ones must be made to Sakpatenti. Registration of a PDO confers legal protection within Georgia, and Georgia seeks protection by treaty for its PDOs in foreign countries. The Sakpatenti website lists the Georgian GIs (here including PDOs) recognised abroad by treaty, and the foreign ones recognised by Georgia. Apparently, only the first 18 Georgian PDOs are currently recognised by the EU. They are the ones described in this Sakpatenti publication of 2010, and shown on the above map. Note that the PDO descriptions in this book are different to the ones referred to in my table, and are quite vague about aspects like mandated grape varieties.

For the definitive and up-to-date list of all Georgian PDOs and GIs (not just the wine ones), and the registration documents with details about each one, see the State Registry in English or in Georgian. The Georgian documents are the definitive versions, and some of the English translations are dodgy. So if in doubt, I would recommend running the Georgian through Google Translate to get a second opinion. It is not too difficult if you use the registration numbers, and document section numbers, to help you orient yourself in the Georgian space.

So far in this mini-series on Georgian PDOs, I have tried to stick to objective facts. But next time, I shall conclude my series with opinion.

Edit 22/02/22: Updated to add Kisi Magraani PDO, which was registered in May last year

Edit 08-09/11/23: Updated to add the PDOs Asuretuli Shala, Okami, Okureshis Usakhelouri and Zegaani, registered between 20/08/22 and 12/12/22. Additionally, I noticed that Sakpatenti have changed some older PDO documents. I’m not sure how big these changes were, but I have updated all the copies linked to from this page

Georgian wine PDOs – a quick guide

Most Georgian wines are marketed by grape variety and the reputation of the winemaker, so as far as the consumer is concerned the country’s PDOs (the equivalent of French Appellations) are often of little relevance. However, there are a few that you might come across in the UK, and here I briefly describe the four that immediately sprang to mind when I was thinking of compiling a shortlist. Later checking showed that they also happen to be the Georgian PDOs most readily available in the UK. And, as they were all in the first six PDOs to be registered, it seems that they were considered to be amongst the most important in Georgia.

These PDOs come from the regions of Kakheti and Racha, and the maps below show you immediately where those regions are within Georgia, but you need to click a few times to get to hi-res maps that show you the location of the PDOs.  The maps do not show physical geography, but it is worth noting that the Alazani river in Kakheti flows in a wide plain, while the Racha vineyard area is more mountainous.

Tsinandali PDO is named after a village in Kakheti, the region where the majority of Georgian wine comes from. This is a dry white (i.e. not orange) wine from the area around the village, made using the Rkatsiteli grape variety with up to 15% Kakhuri Mtsvane. Rkatsiteli is the most common Georgian grape variety, and Kakhuri Mtsvane is also quite popular, and sometimes simply called Mtsvane. The Tsinandali wines that make it to the UK are often relatively inexpensive, and I find them to be straightforward and refreshing. They could perhaps be compared to Chablis, though I would say Tsinandali is more aromatic. I would most naturally think of serving them with white fish.

Mukuzani PDO is also named after a Kakheti village, but this is a dry red wine, and made solely from Saperavi, the most common Georgian red grape. Saperavi wines are usually very dark, an almost opaque purple, and often have a dark and brooding taste profile to match, with smokey fruit. They can also have a fair whack of tannin. Beyond that though, I cannot say I have noticed anything distinctive specifically about the Saperavi from Mukuzani, though as with Tsinandali I have mainly tried cheaper examples imported into the UK. These are wines that can stand up to strong flavours – spices, and beef.

The final two PDOs in my shortlist are Kindzmarauli and Khvanchkara. Frankly, I think the only thing most UK wine drinkers need to know is that these are unfortified semi-sweet red wines, and thus are vini non grata (excuse my, er, Latin) because they do not conform to modern so-called good taste. But please do not dismiss them out of hand. Served at cellar temperature, I find the ones with good balancing acidity and/or tannins very attractive, and they can work very well with grilled meats. But do be aware that they are not sweet enough to function as pudding wines. Kindzmarauli is another Kakheti Saperavi wine, but from the other side of the Alazani river from Tsinandali and Mukuzani. Its name suggests that it comes from somewhere called Kindzmara, but I cannot find such a place on the map. Khvanchkara is made from two lesser-known varieties, Aleksandrouli and Mujuretuli, and is named after the village of Khvanchkara in Racha. Traditionally, these semi-sweet wines were made from ripe late-harvested grapes, which gave a fermentation that naturally arrested due to cold winter temperatures and high alcohol content. That method is sometimes still employed, but these days stopping the fermentation with artificial refrigeration is a lot more common.

So those are my top 4 Georgian PDOs. In my next post, I intend to take a more formal look at Georgian wine PDOs in general, and briefly mention all 24 of them, with links to their official registration documentation.

Txakoli, Txakolina or Chacolí?

You may already know that Txakoli, Txakolina and Chacolí are names used for the light and sharp white wines of the Spanish Basque country. But can they be used interchangeably, or are there subtle differences to be aware of? I have been confused about this issue for some time, and if you have too, you are now in luck – I am about to explain. (But if you really don’t care, feel free to get on with the rest of your life.)

The Basque noun for the wine could be either Txakoli or Txakolin (with an n). However the Basque nationalist Sabino Arana, in his spelling reform of 1895, proposed standardisation on Txakoli, so that is what you normally see now as the wine’s unadorned name in Basque.

The a at the end of the Txakolina is actually the Basque definite article, but you will note that it is not added to Txakoli, but Txakolin, which is the only reason why I bothered telling you about the Txakolin spelling at all. So Txakolina could be translated into English as the Txakoli. You will see Txakolina in the Basque PDO names Bizkaiko Txakolina, Getariako Txakolina and Arabako Txakolina. In these names the ko endings signify the genitive, like the apostrophe s does in English. So you might translate the PDOs into English as The Txakoli of Bizkai, The Txakoli of Getaria and The Txakoli of Araba.

Chacolí is simply the Spanish (i.e. Castillian) version of the Basque Txakoli, and I believe the two words would be pronounced very similarly in their respective languages. Hence, you also get the official Spanish names for the PDOs: Chacolí de Bizkaia, Chacolí de Getaria and Chacolí de Álava.

Incidentally, while Txakoli is the base word, and it often appears on wine bottle labels, it does not seem to be protected as an EU traditional term (it is not listed in Commission Regulation (EC) No 607/2009 Part B), while Chacolí-Txakolina does have protection.

I’m going to bow-out here while I still feel on safe ground, but if you want more information about the linguistics of Txakoli, and the wine itself, you could try the Txakoli Wikipedia article. And, if you can read Spanish, or are prepared to muddle through with an automatic translation, you might be interested in part 1 and part 2 of Del vino chacolín al txakoli on the euskonews website. I am also very grateful for help received on the WordReference Language Forums.

The Importance of Being Bottled

Wines not bottled at source have a bit of a bad reputation for many people, and it seems the main reason is the lack of guarantee of origin and quality, something that is supposedly conferred by the producer’s bottle and label.

A moment’s thought however reveals that any guarantee is far from absolute. Bottles and labels can be faked, and they offer no protection from rogue producers. Also, wine can now be transported efficiently and safely in bulk, with traceability afforded by documentation and information technology.

The guarantee is really only required when there are significant distances between production and consumption – in wine-producing regions empty containers are often taken to a nearby producer for refill. The locals are of course in a great position to know the seller’s reputation, and may even make wine themselves.

As far as small producers are concerned, selling to locals is one thing, but bottling their wine is often the key to getting better prices from large cities, and possibly other countries. And once in a bottle with a label, wine can take a very different position in society. It is no longer a lightly processed agricultural product, only of local significance, but an international lifestyle product. The larger and cheaper brands are designed for the mass market, while more expensive wines available in smaller quantities become desirable luxury goods. At the luxury end of the market, connoisseurship is enabled by bottles and labels. They allow critics to write about a particular wine and vintage, and punters that are possibly in another part of the world can then buy what purports to be the same wine. Even if it is common knowledge that wine can vary considerably between bottles of the same lot, particularly for older vintages, somehow that variation is conveniently forgotten by connoisseurs when obsessing over wine. Thus, labels change how the product is regarded, and they can so easily mislead.

The culture surrounding natural wines largely ignores conventional wine connoisseurship, and I think in many ways it would be more at home with the idea of bulk wine – something meant to be quaffed rather than sipped. Is not bottling one of the most unnatural things you can do to a wine? Even if you leave out the preliminary steps of fining, filtering and dosing with sulphites, squeezing wine into a closed space with little oxygen cramps its style. However, bottling is important to reach the more lucrative market city markets and their natural wine bars. Best not use a traditional wine label though – rather get a mate to design something funky and rebellious, so those connoisseur types know to stay away.

There are comparisons to be drawn between en rama Sherries and natural wines. Strictly speaking an en rama Sherry is taken directly from a solera cask, and valued for its fresh and lively character. Which is all very well if you have access to casks in a Sherry bodega, but not so handy if you live in another country. So Sherry houses now offer the en rama experience oxymoronically from a bottle, where its contents have only minimal processing – perhaps a little fining, only coarse filtration, and minimal sulphite usage. And in doing so, unlike many natural wine producers, it seems they have a product with connoisseur-appeal.

If only for environmental reasons, we need to explore alternatives to bottling wine at source, even if there are huge image problems to overcome for most customers. The romance of drinking unbottled wine in situ might, just might, be a starting point to convince some people. It would work for me, but then I am a far-from-typical wine drinker.

The Wines of Georgia – book review

The Wines of Georgia by Lisa Granik MW, is published by Infinite Ideas in the Classic Wine Library series, with a recommended price of £30. I couldn’t find it cheaper at the usual discounting online booksellers, but it is worth googling for a discount code to buy directly from the publishers. As I write, there are substantial reductions available for WSET, MW and CMS students and/or alumni. By way of disclosure, I should point out that I was given a review copy.

In broad terms, the organisation follows the pattern of many wine books whose topic is a country or major region. Firstly there is background information, separated into chapters on geology, history, wine culture, and a rather large one on local grape varieties. Then, apart from some closing thoughts, each subsequent chapter takes a Georgian region as its subject. The size of each region’s chapter reflects the extent of its winemaking activity, so the Kakheti chapter is another large one, as Kakheti is responsible for the majority of wine production in the country.

My second reviewer disclosure is to declare how much of the book I actually read. Most background chapters were read carefully, but I skipped through the grape variety and regional chapters to get a general impression, pausing only to read in more detail where I was more familiar with the subject matter, or where something in particular otherwise caught my attention. I suspect this reading pattern would not be untypical, as the later chapters would be heavy-going if read in a linear fashion, and are a lot more suited for reference material.

My general impression is that the book is well-researched and detailed. Not only has Lisa travelled extensively in the country, but she has consulted organisational authorities, and read in some depth on the subjects she writes about. Thus for example, she avoids the retelling of Georgian history according to folk memory, and offers a more nuanced interpretation of Georgia’s Soviet period. There are but a handful of comments in the text that I find questionable, but they could be largely put down to emphasis and interpretation, and are certainly not significant enough to merit analysis here.

The tone is generally formal and serious, so you have to be on your guard or you will miss the occasional flashes of dry humour. One consequence of this tone is that Georgia’s romance is downplayed, along with its people, food and countryside. But that’s fair enough, the main topic after all is wine, and a single book cannot be expected to cover everything.

The regional chapters, which comprise around half the book, are packed with solid and interesting information. However, they might be easier to navigate if more structure were imposed on them. Thus, while they contained solid information on the geography, geology, PDOs, and producers, it was not always obvious where to find it. If structure  does exist in the regional chapters, then it is perhaps more a criticism of the publisher’s layout and typography than the author. A finer level of detail in the table of contents would have helped, as would a better index.  For example if you want to know about Kindzmarauli, a word you may find on a Georgian wine label, it does not have its own top level index entry; you have to know to look under Protected Designations of Origin, and then Kakheti.

Better maps would also have helped in some of the explanations in the regional chapters. Map quality in wine books is a constant complaint of mine, and actually the ones in this book are better than most. It is really only the Upper Kakheti map that attempts to cram in far too much information – but this is sadly the one that covers most of the country’s wine production.

On the positive side, I was very pleasantly surprised to see what I thought was a very balanced approach in any discussion of homemade and natural wines. This subject is usually divisive, and while a fair amount of writing on Georgian wine has come from cheerleaders of the natural wine movement, MWs seem to often adopt the opposite, very disdainful, stance. The cheerleaders may make my eyes roll, but it the disdain irritates me more. Anyway, I finished up unirritated, with eyeballs intact, and just a little curious as to exactly where Lisa draws the line between faultiness and acceptability in natural wines.

The blurb on the back cover claims that this is the definitive book on Georgian wine. I am not sure I agree, if only because I am not sure a definitive book can exist for a subject matter that is changing so rapidly. But I would go so far as to say it is the best book to date, without a shadow of a doubt. So if you want to learn about Georgian wine, this should be your first port of call.

New decade – new look

The theme that determined the look of my blog a few moments ago was 10 years old, and deemed to be obsolescent by various 3rd parties. Hence, I was pushed very much towards an update of my website’s appearance, and I have a new theme. It is now Responsive, which is considered to be a Good Thing – not least by Google apparently when it calculates the weightings to use for page rankings. Personally, on smaller devices I think it now looks a lot better than it used to, but worse on laptop and desktop machines. That’s progress.

Anyway, I know there are a few niggles with some older posts, but otherwise everything seems to be working. However, if you notice any problems please do let me know. Meanwhile, I’ll try to get working on new content.

Happy New Year!

Sulphites in wine

Over the last few weeks I published a mini-series of posts on sulphites in wine, trying to go into a bit more depth than is usually found, and referring to my evidence base where possible. It is also perhaps a bit technical in places, but I hope it strikes the right balance at least for some winelovers.

The main thread of the posts starts with introductory material, including sulphite allergies, and a bit about typical sulphite concentrations, and limits specified by the various regulatory bodies. Then, after brief discussion of sulphite-induced headaches, which I see as a bit of a side-issue, I move on to the effect of sulphites on flavour. My posts are linked to below:

Clearing up a few points

Maximum and typical concentrations

Headaches

Effect on flavour

I must admit that when I started writing about sulphites, my view was that the issue was quite cut-and-dried, and they got far too much attention in the wine-world. I now see that sulphites are a lot more important than I thought, and not only for  wine-preservation and health reasons. The extent to which sulphites are good or bad is now not entirely clear to me, but I am convinced that sulphite-usage decisions are not to be taken lightly.

Sulphites in wine – headaches

Before I get back to posting more techy-stuff about sulphites in wine, here’s a brief diversion into the question of whether sulphites in wine can cause headaches.

Two things are clear. One is that, as far as I know, there is no scientific evidence that they do – we know that sulphites may result in a number of various symptoms in a small section of the population, but headaches is not one of them. The second is, despite that, quite a few people do believe that sulphites cause headaches, and have anecdotal evidence to support their belief. And of course a lack of scientific evidence for a proposition does not mean it is wrong.

The main problem with the anecdotal evidence is that wine contains another chemical, one that we know for sure causes headaches: alcohol. And there are also other chemicals that could conceivably do the same. So if you suffer from wine-related headaches how might you attempt to identify what is the culprit?

An easy first step would be to establish which wines are more likely to give you the worst headaches. Are sweet ones the worst? Followed by dry whites, and with red wines least likely to give you headaches? If so, that pattern is consistent with sulphites being to blame, because sweet wines are likely to contain more sulphites than dry ones, and white wines more than reds. On the other hand, if red wines are the worst, then it is more likely to be due to a chemical extracted from grape skins. A possible culprit is histamine – you could test for that by seeing if an antihistamine helps (but do check first that it is OK to consume alcohol with the drug). Or of course red wines might be giving you more headaches simply because they tend to contain more alcohol.

You could also compare your normal wines with ones that have particularly low sulphite levels. Generally speaking, a better quality wine, or something natural, biodynamic or natural, will be likely to have lower sulphite levels. But to be sure that you are comparing with a low sulphite wine you could go to the Raw Wine website and search for wines with levels under, say, 20 ppm. If lower sulphite wines give you fewer headaches it may still not be the sulphites themselves that are making the difference, as wines with low sulphite levels are probably low on other additives too. But on the other hand, if you like the low sulphite wine you might consider your problem solved anyway, so who cares?

Another approach would be to note if other sulphite-containing food and drink gives you headaches. Bright orange dried apricots are said to contain up to 1,000 ppm of sulphites. That’s a lot more than would be allowed in any wine, though to be fair you are likely to consume more wine in one session than apricots. Here’s a list I found of food and drink containing more than 100 ppm sulphites:

Dried fruits (excluding dark raisins and prunes)
Bottled lemon juice (non-frozen)
Bottled lime juice (non-frozen)
Wine
Molasses
Sauerkraut (and its juice)
Grape juices (white, white sparkling, pink sparkling, red sparkling)
Pickled cocktail onions

I feel a bit ill reading that list, but if you can pig-out on dried apricots, molasses, sauerkraut (and its juice) and pickled onions without getting a headache, probably sulphites are not responsible for your hangovers.

All the above suggestions are as unscientific as any assertion that sulphites cause headaches. The best they can achieve is to give you a little more understanding of how you personally react to sulphite additives, and I’m afraid that’s the best I can offer.