What is made here
Wine colours
The only colour the rules allow.
Where it is
Fronsac in France
- Latitude
- 44.9°–45.0° N
- Vineyard altitude
- 4 m to 77 m
- Delimited vineyard land
- 1,730 ha
Lies within
Bordeaux supérieur, Bordeaux, Crémant de Bordeaux
Contains 1 appellation (outlined on the zone map)
Canon Fronsac
Worked out from the boundaries (smallest container first). Uses the delimited parcels where INAO publishes them.
The delimited vineyard parcels themselves, so the shape is patchy: only land within them may grow the wine. Boundary: INAO parcel delimitation (Licence Ouverte); nearby parcels drawn as one block, with less detail for larger appellations. Country outlines: Natural Earth. Dots on the zone map are the vineyard points used for climate.
01 · What the law says
The rules
Limits on grapes, yields, ripeness and ageing that every wine labelled Fronsac must meet.
Blend rules
Fronsac
- ≥ 80% cabernet franc / cabernet-sauvignon / merlot / cot · Main grape
- ≤ 10% Carmenère · Allowed
- ≤ 10% Petit Verdot · Allowed
; release from 30 June of the year after the harvest.
Other varieties allowed
Besides the main grapes, the rules allow these varieties in some wines. Grape names link where a profile exists.
3 varieties · Fronsac
In the vineyard and cellar: rules for every wine
5,000
Vines per hectare, minimum
Training
Systems allowed
taille Guyot simple; Guyot double; taille à cots en cordon; taille à cots en éventail; taille à astes
Permitted
Irrigation
Allowed
Enrichment (chaptalisation)
02 · Climate fingerprint
The climate
The growing season averages 17.8 °C, warm on Gregory Jones's scale, with 1,668 growing degree days (Winkler III).
The average year 1991–2020, vineyards at about 31 m
Monthly mean, °CRain, mmGrowing season
- Growing-season temperature
- 17.8 °C
- Warm · 17–19 °C (Jones)
- Growing degree days
- 1,668
- Region III: 1,667–1,943 degree days
- Growing-season rain
- 456 mm
- Of 799 mm a year
- Harvest rain
- 130 mm
- September–October
Copernicus ERA5-Land monthly averages at 5 vineyard points (Vineyard point 1, 84 m; Vineyard point 2, 34 m; Vineyard point 3, 3 m; Vineyard point 4, 30 m; Vineyard point 5, 3 m), moved to each point's height from the model's terrain. Indices that need daily data are not captured yet. How the climate figures are made.
Closest climates in the database
Picked by the data, not by hand: the profiles nearest on season warmth (counted twice), degree days, rain, ripening-month nights and day–night range. Neighbours within 30 km are left out, as they share the same weather.
1. MehedinţiVery similarCompared with Fronsac: same season warmth, similar rain.
2. Saint-SardosVery similarCompared with Fronsac: same season warmth, similar rain.
3. CadillacVery similarCompared with Fronsac: same season warmth, similar rain.
Growing-season temperature
Growing degree days
Growing-season rain
03 · Year by year
35 vintages
Each column is one growing season: heat above or below the 1991–2020 average, and rain at harvest. Pick a year for the details.
Warmer than averageCooler than averageHarvest rain (Sep–Oct)Average harvest rain, 130 mm
2025
- Growing-season temp.
- Growing degree days
- Harvest rain
- Growing-season rain
- September nights
- Hot days and frosts
Seasons are labelled by harvest year (April–October). Year-to-year changes from ERA5-Land; tested against station records in Alto Adige (r = 0.94 for season temperature at Bolzano). Rain varies more locally, so treat single-season rain with some caution. Vintage ratings, harvest dates and frost or hail events have places in the data model but are not loaded yet.
04 · Where the numbers come from
Sources
- A geospatial inventory of regulatory information for wine protected designations of origin in Europe · Candiago et al., Scientific Data 9, 394 (2022); Eurac Research · CC0
- Quality wines in Italy and France: a dataset of PDO specifications · figshare 25393261 · CC BY 4.0
- ERA5-Land monthly averaged data (reanalysis-era5-land-monthly-means) · Copernicus Climate Change Service (C3S), Climate Data Store · CC BY 4.0 (Copernicus licence)
- OpenStreetMap vineyard areas (landuse=vineyard), from Geofabrik country extracts · OpenStreetMap contributors · ODbL 1.0
- Copernicus DEM GLO-90 (AWS open data tiles) · European Space Agency / Copernicus · Copernicus DEM licence
- Cahier des charges: Fronsac (Cahier des charges de l'appellation d'origine contrôlée Fronsac, homologué par arrêté du 10 décembre 2024 (AGRT2425031A) - BO n°51 du 19 décembre 2024) · Ministère de l'Agriculture (Bulletin officiel), as linked by INAO · Official act
- Délimitation parcellaire des AOC viticoles de l'INAO · Institut national de l'origine et de la qualité (INAO), via data.gouv.fr · Licence Ouverte / Open Licence (Etalab)
- Appellation nesting worked out from boundaries (pipeline/build_nesting.py) · Vinous, from the Eurac PDO boundaries · CC0 (source data)
- Climate profiles calculated by Vinous: method
Still to check (3)
- Generated from EU reference data: check against the current product specification.
- From the specification: The 80% minimum for principal varieties and 10% cap on each accessory variety apply to the holding's vineyard; in the blend principal varieties must be at least 50%. Merlot needs at least 198 g/l sugar (180 g/l for other varieties); irrigated parcels are limited to 6,500 kg/ha; wines are aged (élevage) until at least 1 June of the year after the harvest, with maximum 0.30 g/l malic acid.
- National tier (DOC/DOCG) not captured yet; rules extracted from the specification text.