[4][5][6] Pomerol is the smallest of the major fine wine regions in Bordeaux, covering an area that is roughly 3 by 4 kilometres (1.9 by 2.5 mi) in size.
In 1998, there were 784 hectares (1,940 acres) of grape vines planted within the AOC boundaries producing 36,066 hectolitres (952,800 US gallons) or 400,733 cases of wine.
[7] Though it is difficult to pinpoint exactly when grapes were first planted in the Pomerol region there is enough evidence to show that viticulture was present in the area during the time of the Romans.
The area's location along the major pilgrimage route to Santiago de Compostela in Spain also attracted the interest of the Knights Hospitaller, returning Crusaders who set up several hostels and hospitals in the region.
In 1760, Louis-Léonard Fontémong, a Libournais négociant, planted what appears to be the first documented instance of Merlot in the region, in a vineyard that is now part of Château Rouget.
However, he found that market heavily saturated, so he moved across the river to the Libournais region and opened up a négociant house in the city of Libourne in 1937.
This means that Pomerol sees more diurnal temperature variation during the growing season, between daytime highs and evening lows.
[11] Nevertheless, the threat of harvest rains is still present in Pomerol, especially for winemakers employing the philosophy of "extended hanging" time in order to prolong the ripening process.
When rain does occur it can pose a significant risk of grey rot, especially for Merlot planted on heavy clay soils which tend to retain water.
[1][12][13] While very hot vintages (such as 2003 and 2009) can create problems of over-ripeness in Merlot, the Pomerol region (and the Right Bank as a whole) tend to fare better during cooler years (such as 2006 and 2008).
The main viticultural hazards are spring time frosts, which can occur frequently in the Pomerol region and disrupt entire vintages.
Unlike most of the most prestigious communes of Bordeaux, it has no direct river access, being separated from the Dordogne to the south by the town and by Saint-Émilion, which lies to the south-east.
It stands on a gravel bank (a feature it shares with the prestigious appellations of the Médoc); towards the south and west, the soil is more sandy, while towards the north and east, it tends to clay.
The plateau on which Pomerol sits is bordered by three rivers, the Barbanne to the north, the Isle to the west and Dordogne and the city of Libourne to the south.
[3] Within the region of Pomerol lies what is described as a bouttonière (or "buttonhole") of unique blue-clay (known as molasse) sitting on top of band of sand rich in iron deposits that is known as crasse de fer or machefer.
[3] According to Catherine Moueix the "clinkers" of iron tinted sand adds aroma notes of violets and truffles while Alexandre Thienpont of Vieux Château Certan says its benefits are more viticultural, in limiting the vigor and excessive leaf growth of the vine.
However, despite its association with Château Pétrus, not every wine grower in Pomerol extols the virtues of having crasse de fer on their property.
[3] For most of the 20th century, the winemaking styles of Pomerol were influenced by University of Bordeaux oenologist Émile Peynaud and his work on the Cabernet Sauvignon grape in the Médoc.
[11] Tradition in Pomerol has been to separate the free-run wine and blend back in a proportion of the vin de presse as needed depending on the vintage.
[3] World-renowned winemaker Michel Rolland was born in the Pomerol region and has a family estate, Château Le Bon Pasteur, that he co-owns with his wife Dany.
The remaining permitted grapes, Cabernet Sauvignon and Petit Verdot, are barely planted and rarely used in the grand vin though, like Malbec, they may appear in an estate's second wine.
[3][4][5] In the early 20th century, as Pomerol's transition to a red wine producing district was completed, Cabernet Franc was the dominant grape variety.
However, an early spring frost in 1956 killed a large portion of the Cabernet Franc plantings and many estates took this event as an opportunity to replant with the higher yielding and earlier ripening Merlot.
Nevertheless, very few Pomerols are pure Merlot and Cabernet Franc is still valued for the tannic structure and acidity it gives, which can add longevity and aging potential to the wines.
[4] Johnson notes that Pomerols are usually distinguished by their deep color and sometimes creamy, concentrated ripe-plum flavors but without the high acidity and tannins that are typical of other Bordeaux wines.
Some producers, such as Nicolas de Bailliencourt of Château Gazin, believe most of the opposition is from small growers who fear being left off any ranking making their wines perceived to be inferior.
[5] Pomerol is well noted for the unassuming rural flavor that is a sharp contrast to the grand châteaux and ornate architecture that distinguishes many wine estates of the Médoc.