Lieu-dit · Sermiers
Le Petit Cosson
Le Petit Cosson is a lieu-dit in Sermiers, Montagne de Reims, Champagne, whose largest tier is premier cru.
14.6 ha
delimited
158 m
elevation
11.5 h
sun at harvest
Open on the mapWith the boundary, the plots, the sun through the year and the bedrock.
In figures
| Level | Premier Cruinao-aoc-viticoles-bulk (not in this commune) |
|---|---|
| Village | Sermiers |
| Region | Montagne de Reims, Champagne |
| Delimited | 14.6 hainao-aoc-viticoles-bulk (not in this commune) · cadastre-etalab (4 September 2026) |
| Planted | 12.4 hacadastre-etalab (4 September 2026) · ign-bdtopo-vigne (4 September 2026) · ign-rpg-2024 (5 September 2026) |
| Parcels | 32 |
| Grape variety | meunier 68 %, pinot noir 22 %, chardonnay 11 % also permitted: arbane, petit meslier, pinot blanc, pinot grisinao-cahiers-des-charges (7 September 2026) · dgddi-superficies-produits (7 September 2026) · franceagrimer-observatoire-viticulture (7 September 2026) |
| Organic | 0%agence-bio-cartobio (c. 5 September 2026) · agence-bio-operateurs (5 September 2026) |
Place in the village
Among the 66 named plots ranked premier cru in Sermiers, from high to low:
Position
158 m
elevation
6.6%
firm
E
east
mid-slope
even slope
| Elevation | 158 m 144 to 174 mign-rge-alti (5 September 2026) |
|---|---|
| Daytime temperature | +0.17 °C by day, relative to the village centre at 182 m, ± 0.07 °Cmeteo-france-quotidiennes (6 September 2026) · meteo-france-postes (6 September 2026) · meteo-france-lsh (6 September 2026) · ign-rge-alti (5 September 2026) |
| Slope | 6.6% 3.8°ign-rge-alti (5 September 2026) |
| Aspect | east 100°ign-rge-alti (5 September 2026) |
| On the slope | 26% mid slope, on an even plane, 246 m drains onto itign-rge-alti (5 September 2026) |
Bedrock
- 5%Colluvium, mixed slope deposit about 0.1–0 million years
- 35%Ypresian clay with lignite 56–53 million years
- 33%Thanetian sand of Châlons-sur-Vesle 59–56 million years
- 27%Calcareous sandstone of Mont Chenois and marl of Chenay about 59–56 million years (Thanetien)
Not a borehole: ordered by age, thickness by share of surface.
In the glass. The rounder style of these slopes comes first and foremost from the share of Meunier and from the aspect. The clay plays a part through a larger water store and more vigour, not as a source of flavour.
Fat, plastic clays in varying colours, white to almost black, with thin sand interlayers and discontinuous seams of lignite. They were deposited in lagoons, marshes and delta plains at the start of the Eocene, roughly 56 to 53 million years ago; the type section lies near Épernay, hence the old name Sparnacien. In the ground this is not rock but heavy, sticky clay, locally with pyrite and wood remains.
For the vine. The clay holds a very large amount of water, which is a buffer in a hot summer, but in spring the ground stays cold and wet and roots penetrate it with difficulty. Without a slope and without a permeable layer above it the soil quickly becomes saturated; on slopes this clay forms the slip plane along which springs and landslips occur. The soils on it contain little active lime, so chlorosis hardly plays a part, but vigour and late ripening do.
Characteristic of the mid and lower slopes of the Vallée de la Marne and parts of the Montagne de Reims.
BRGM geological map at 1:50,000. It tells vineyards apart, not plots within a vineyard. The link between rock and taste is indirect: soil depth, water and warmth do the work, and slope, vine age and the cellar do the rest. Units on that map: e4a, e3cC, e3cGM, C.
brgm-bdcharm50 (4 September 2026)Sun and horizon
07:35
above the hill
19:05
behind the hill
11.5 h
sun at harvest
Grey: sun up, but behind the hill or the vineyard's own slope.
Around harvest the sun rises here at 07:35 above the hill and disappears at 19:05 behind the hill: 11.5 hours of direct sun on a clear day. The ridge reaches 7.4° above the horizon to the west-southwest.
| Irradiation | +0.1% versus flat land 969 kWh/m² from April to October, 48% of it diffuseunder the average cloudiness of 2005 to 2023 (PVGIS-SARAH3, EU JRC); direct, diffuse and reflected light togetherign-rge-alti (5 September 2026) · ign-lidarhd-mnh (6 September 2026) · ign-bdforet-v2 (5 September 2026) · jrc-pvgis-sarah3 (10 September 2026) |
|---|---|
| Open sky | 99.6% of the sky the slope itself sees; the surrounding relief blocks the restign-rge-alti (5 September 2026) · ign-lidarhd-mnh (6 September 2026) · ign-bdforet-v2 (5 September 2026) |
Three reference days and the caveat
| rise | set | sun | day | |
|---|---|---|---|---|
| 21 June | 05:41 | 21:24 | 15.7 h | 16.2 h |
| 20 September | 07:35 | 19:05 | 11.5 h | 12.3 h |
| 21 December | 08:58 | 15:55 | 7.0 h | 8.2 h |
Computed from the IGN elevation model at 5 m: horizon in 36 directions up to six kilometres, sun position per minute, angle of incidence on the mean slope. Clear sky, with the tree canopy from the IGN forest inventory as a raised horizon (15 m closed forest, 5 m heath, trees within 60 m ignored), 41% of the far field is forest (BD Forêt), no buildings.
Air and cold
15 m
above the lowest point
drains away
cold air
a main drain
206.4 ha flows past
| Cold air | 15 m above the hollow, cold air drains awayign-rge-alti (5 September 2026) |
|---|---|
| Cold air passing through | 206.4 ha a main drain, mean over the polygon 1.47 haign-rge-alti (5 September 2026) |
Planting
SE-NW
down the slope
1.58 m
between the rows
100%
vineyard in 1950
| Rows | SE-NW (127°) down the slope (27°), every 1.58 m, varies by plotmeasured over 12.2 of 12.4 ha plantedign-bdortho (6 September 2026) |
|---|---|
| Vineyard in 1950 | 100%assessed over 12.5 ha on the 1950-1965 aerial photographign-photos-historiques-1950-1965 (6 September 2026) |
Climate over time
station REIMS-COURCY, 91 m, 17.2 km away
growing season, April to October: 1951-1980: 14.1 °C, 1991-2020: 15.0 °C
Huglin index: 1951-1980: 1,477, 1991-2020: 1,639
last spring frost: 1951-1980: day 118, 1991-2020: day 107
raw daily series, not corrected for station breaks
The name
- petit
- small, the counterpart of grand. Shape and position · Terroirium, Eigen telling over de namen in deze atlas (2026)
This is about the words, not about this plot: the same name can have arisen differently elsewhere.
Who owns land here
10.6 ha of 14.6 ha delimited is registered to a legal entity
- SAS VITICOLE DU DOMAINE DU COSSON69%
- ASS FONCIERE DE REMEMBREMENT DE SERMIERS2%
- SOCIETE CIVILE DU VIGNOBLE MARCEL PIERRE1%
- SOCIETE G H MARTEL ET CIE1%
- private individuals or unknown27%
- 10.0 ha GFA DU DOMAINE DU COSSON GFA · land company
- 0.36 ha ASS FONCIERE DE REMEMBREMENT DE SERMIERS AUPM · other
- 0.10 ha SCI DU VIGNOBLE MARCEL PIERRE SCI · land company · bare ownership
- 0.10 ha SOCIETE G H MARTEL ET CIE SA · other · usufruct
Private individuals or unknown: 3.99 ha.
Share of the delimited hectares. Only legal entities are public in France; everything else stays unnamed. From the public register of legal entities (DGFiP), as of 1 January 2025. The owner is not always the one who works the vineyard: tenancy is common.
Nearby lieux-dits
- Les Vignes de Bas Premier Cru · 350 m
- Les Clos Premier Cru · 350 m
- Les Ludets Premier Cru · 400 m
- Les Petits Chamettes Premier Cru · 450 m
- Le Pré Lavocat Premier Cru · 450 m
- Les Charmettes Premier Cru · 450 m
- Les Becs a Chamery Premier Cru · 500 m
- Les Presles Premier Cru · 500 m
In the same village, measured between label points. That does not say which ones border each other; the map shows that.
Where each figure comes from
- Classification
- The INAO delimitation per denomination, cut against the cadastral parcel. Only the INAO's own plans are legally binding; this map is informational.
- Area
- Computed on the sphere from longitude and latitude (turf.area), not in Lambert-93. For an appellation this is the union of the INAO polygons across commune boundaries, measured on the unclosed geometry; the fifteen metres used to close the outline for the map are not counted. For a climat it is the union of the cadastral lieu-dit polygons with that name.
- Planted
- Parcel area times vineyard cover, where cover comes from the IGN vegetation layer supplemented by the agricultural declaration. Checked against the customs harvest declarations: median deviation 5.1 per cent over a hundred appellations.
- Elevation
- Mean of the elevation-model cells whose centre falls inside the polygon, on a 5 m grid.
- Slope
- Per-cell slope from the elevation model using Horn's method, then averaged over the cells in the polygon.
- Aspect
- Vector mean of the per-cell aspect. A plain average would turn north-east and north-west into south.
- Sun at harvest
- Hours of direct sun on 20 September under a clear sky, with the horizon in 36 directions out to six kilometres and the height of woods and buildings on top of it. Canopy height is measured where LiDAR HD covers the area and estimated from BD Forêt where it does not; the panel states which of the two was used.
- Grape variety by appellation
- Per appellation and colour the permitted varieties from the approved cahier des charges; per appellation and tier the declared hectares of white and red from the customs harvest declaration (product codes). One colour permitted: the main variety of that colour. Two colours: from 85 percent of the hectares that colour applies, in between it is called mixed. Champagne: the dominant variety from the planted hectares per variety per commune from FranceAgriMer. Per polygon the dominant variety of its parts by area. Derived, not measured: the variety per plot exists only in the customs vineyard register, which is not public. In a two-colour appellation a single plot may carry the other variety. Customs withhold small appellations (statistical secrecy), in which case the split is missing.
- Bedrock
- The geological unit covering the largest share of the polygon, from the 1:50,000 geological map. At 1:50,000 the map separates one climat from another, but not what varies inside a climat.
- Organic
- Share of the area certified organic or in conversion, from the CartoBio plot register.