Open Wine Map: every European appellation on one interactive map

All the wine rules were already online, just scattered. Boris De Vloed brought them together on a single map of twenty European wine countries.

Belgian IT consultant Boris De Vloed built Open Wine Map in two months: an interactive map of the appellations across twenty European wine countries. It shows which grape varieties are permitted within a region, how appellations connect geographically, and which official sources the information is based on.

Take Côte-Rôtie. The label rarely mentions that this red wine is built on Syrah and, under its cahier des charges (the legal specification, or product dossier, that defines an appellation), may contain up to 20 percent Viognier. The appellation name assumes the buyer already knows. Open Wine Map makes that framework visible: click on the region, and you see its location, the permitted varieties and the neighbouring areas.

That still amounts to no firm taste advice. The map shows what producers are legally allowed to use, not what sits in a specific bottle. That distinction is precisely what makes it useful. Open Wine Map narrows the gap between a label and the world behind it, without pretending an appellation fixes how a wine tastes.

Two months of evening work

Boris De Vloed works as an IT consultant, specialised in making government data accessible. He applied that same approach to wine in his spare time.

The trigger was practical. During the Sommelier-Conseil course at the Flemish Wine Academy, linked to the Université du Vin in Suze-la-Rousse, he wanted to see connections that stay hidden across separate chapters. On a map, the Grenache appellations run along the French Mediterranean coast right into Catalonia. And the Loire counts as one overarching name, while Côtes d’Auvergne uses varieties you find sooner in nearby Burgundy than in the appellations known further downstream. De Vloed wanted to make such patterns visible.

He first built a searchable reference tool from his course material. That stayed private because of copyright on the coursework. He then turned to public sources: the cahiers des charges and other documents that set out the rules of appellations. He started with France. Two months later, Open Wine Map covered twenty wine countries, from France and Spain to Malta and Cyprus.

Public is not the same as accessible

The information was largely public already. It just sat spread across specifications, European legislation, geographic files and grape-variety databases.

For France, De Vloed draws on the cahiers des charges and parcel data from INAO, the French institute that safeguards designations of origin. The base map comes from the geographic institute IGN, European legislation via EUR-Lex, and the canonical variety names from the Vitis International Variety Catalogue of the Julius Kühn-Institut. Wikipedia adds descriptive detail, under a CC BY-SA licence and with a source credit, each time.

So the innovation lies not in new data. De Vloed brings existing data together, orders it and links it to a map. That sounds simpler than it is because a wine region can hold several legal layers: a regional appellation, a Village appellation, a Premier Cru or a standalone Grand Cru. Regions also overlap, and every country runs its own system.

The grape varieties, too, are layered per region, as set out in the cahiers des charges. The main variety forms the base; a secondary variety, or cépage accessoire, may join under certain conditions. Alongside these, stand varieties planted for experiment or research, for instance for disease resistance or climate adaptation. So the map shows that an appellation’s permitted grapes can change, partly through climate change.

Honest about precision

Geographic accuracy varies by region, too. Some contours come straight from INAO’s parcel data. Others are reconstructed from cadastral records, or taken over from a larger parent region, as with German Einzellagen and Portuguese subregions. In the right-hand margin of Open Wine Map, you find the sources on which each appellation boundary is based.

De Vloed puts it plainly: he would rather be honest about precision than suggest a false sharpness. A crisply drawn shape creates the impression that a boundary is fixed down to the metre. Sometimes that holds, sometimes the contour is an approximation. The source credit makes the difference clear.

What it does for the user

Open Wine Map is new, and its value grows clearer over time. That value lies in the application, slightly different for each group.

Consumers and retail

European labels often name the origin, rarely the grape. Anyone who meets an unfamiliar appellation sees, within a few clicks, its location, the permitted varieties and the neighbouring areas. For a wine trip, that helps: you check in advance which appellations lie around where you are staying. In the shop, that same speed counts double, for the customer and the seller alike. Both know in no time which grapes are permitted and where the region lies.

Importers

For importers, the map turns interesting later in the process. Once a wine is in the range, the detail panel supplies the building blocks for an information sheet or sales text. Take Verdicchio dei Castelli di Jesi: the permitted grapes, the style, and direct links to the official sources such as EUR-Lex and the eAmbrosia register. The raw terroir description is sometimes technical, but the source links bring you to the original in one click. The map does not replace the current cahier des charges, though; for the legal and technical detail, you go to the source itself.

Sommeliers

For a sommelier, the value lies in the story at the table. When an unfamiliar region comes up, the map gives the geographic context at once. Take Verdicchio dei Castelli di Jesi again: the hilly appellation sits in Le Marche, on the Adriatic side of central Italy, sheltered to the west by the Apennines, cooled to the east by the sea. Such details turn a name on a bottle into a place with character.

Students, academies and research

For students, the gain lies in seeing connections. Wine growing often follows the rivers, climbs against hills or clusters around lakes. On a map you remember such a pattern more easily than a row of loose names. And that is exactly what De Vloed missed during his own course: appellations you learn chapter by chapter in a textbook, whose geographic coherence only becomes visible on the map.

For researchers, the value goes a step further. Anyone who sets climate, soil, and location side by side across many appellations can look for connections that stay hidden in separate sources.

What AI does and does not do

Artificial intelligence certainly plays a part, only not the way many people associate with an ‘AI map’. A language model invents no wine facts here. It does three kinds of work, each time as an instrument.

First, De Vloed has the language model, Claude by Anthropic in this case, write the software that reads the specifications. That code pulls the permitted grapes and wine types out of each specification and links them to the right parcels and map layers. Second, he deployed research agents, small programs that search for sources on their own. Third, Claude summarises the terroir descriptions and makes them available in four languages.

The facts themselves come from official sources and sit in a database. The code is also public on GitHub, a kind of digital workshop where programmers share their source code: the instructions that make a program run. Anyone may look in, point out errors and propose improvements. For Open Wine Map, it means the entire machinery behind the map is open and can be checked.

That does not make the map flawless, though openness does make errors visible and correctable. De Vloed wants everything to be traceable. Distrust the map, and you can open the source behind it and judge for yourself. That is no idle luxury because De Vloed has found and fixed various typing and spelling errors in the cahiers des charges themselves.

Beyond Europe, it gets harder

The current structure suits European wine countries above all, where appellation rules set out in detail what is and is not allowed. De Vloed wants to expand to the United States, Australia and South Africa, where that model fits less well for now. The next step therefore leans more on production data than on regulations. On the map, he keeps that difference visible throughout, so that actual planting and legal permission stay separate. The United Kingdom is on the schedule; Georgia follows once there is a consistent method for regions outside the EU structure.

Free, and staying that way

There is deliberately no revenue model behind it. De Vloed saw no easy way to bring the map to market, and works on it for pleasure, a few evenings a week.

Still, the map is a fine calling card. See Open Wine Map, and you know at once what De Vloed can do: open up public data, order it and make it accessible. Should he ever look for a new assignment, the map is his best recommendation.

Open and free need not clash. Wikipedia, too, began with just an idea and only later placed its intellectual property in a foundation, after which the donations followed. Put that route to Boris, and he responds with interest; he does not rule out that something like such a structure could one day grow from it.

Open Wine Map shows what happens when public wine legislation is not merely published, but also connected, ordered and made verifiable. The rules were already there. What was missing was usable access.

---

This article first appeared in Dutch on Winecastr.com: Open Wine Map: één freelancer ontsluit de wijnregels die Europa versnipperd publiceert, The English version was translated with AI support and checked before publication.

---

Reinier Broeks is a Dutch investigative wine journalist and registervinoloog, the Netherlands' certified wine expert title. Drawing on a background in business economics, he covers the wine world from an economic and cultural angle, on a mission to wake up the industry before the consumer does it the hard way. And the occasional bottle worth arguing about. His Dutch-language work appears at Winecastr.com.

---