What is made here
Wine colours
The only colour the rules allow.
Where it is
Teran in Slovenia
- Latitude
- 45.6°–46.1° N
- Vineyard altitude
- 53 m to 377 m
- Production zone
- 76,975 ha
Lies within
Vipavska dolina
Contains 1 appellation (outlined on the zone map)
Kras
Worked out from the boundaries (smallest container first). They follow whole communes, so a neighbour sharing a commune can show up here too.
Boundary drawn from whole communes, so it is a little larger than the legal zone. Boundary: Eurac Research PDO inventory (CC0). 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 Teran must meet.
Other varieties allowed
Besides the main grapes, the rules allow these varieties in some wines. Grape names link where a profile exists.
1 varieties · Teran PTP, Izbrani teran PTP
Refošk
In the vineyard and cellar: rules for every wine
2,800
Vines per hectare, minimum
Training
Systems allowed
kraški latnik; šparonska gojitvena oblika
Cellar
Where the wine must be made
Within the production zone
Allowed
Enrichment (chaptalisation)
02 · Climate fingerprint
The climate
The growing season averages 17.2 °C, warm on Gregory Jones's scale, with 1,537 growing degree days (Winkler II).
The average year 1991–2020, vineyards at about 251 m
Monthly mean, °CRain, mmGrowing season
- Growing-season temperature
- 17.2 °C
- Warm · 17–19 °C (Jones)
- Growing degree days
- 1,537
- Region II: 1,389–1,666 degree days
- Growing-season rain
- 969 mm
- Of 1,607 mm a year
- Harvest rain
- 361 mm
- September–October
Copernicus ERA5-Land monthly averages at 5 vineyard points (Vineyard point 1, 318 m; Vineyard point 2, 113 m; Vineyard point 3, 258 m; Vineyard point 4, 230 m; Vineyard point 5, 336 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.
Lower confidence:Monthly reanalysis in complex terrain (height corrections up to 2.5 °C); absolute values may be several degrees out, year-to-year changes are more reliable.
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. Friuli Colli OrientaliVery similarCompared with Teran: same season warmth, similar rain.
2. Asolo MontelloVery similarCompared with Teran: same season warmth, similar rain.
3. FaraVery similarCompared with Teran: 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, 361 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
- 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
- Product specification: Teran (SPECIFIKACIJA PROIZVODA- Teran.doc) · National authority, as filed in the EU register (eAmbrosia) · Official document
- 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: Teran is made only from Refošk on the Kraška planota subzone of Kras (wine with recognised traditional designation, PTP). The wine itself must show at least 9.2 % vol natural alcohol (10.8 % for izbrani teran); actual alcohol 10-13 % vol, or at most 11 % vol if the must was enriched (up to 2 % vol, with Refošk concentrated must or up to 3.5 kg sucrose per 100 l); izbrani teran may not be enriched and is bottled only in glass. The 76 % is the wine yield after first racking. Vine density must exceed 2,800 vines/ha for the Karst pergola (kraški latnik) and 3,500 for the šparon system. Destemming is compulsory except for carbonic maceration; acid correction, warm maceration, electrodialysis, cation exchange and hot bottling are prohibited; malolactic fermentation is induced. Unbottled teran may be sold for at most 18 months after harvest. Organoleptic score at least 16.1 (izbrani 18.1).
- National tier (DOC/DOCG) not captured yet; rules extracted from the specification text.