Jamón Ibérico de Bellota is the most delicious, the rarest, the finest and also the most expensive ham in the world. In order for the jamón to be given the exclusive label "de bellota", the Iberian pig must graze freely for about half a year in an oak grove, so-called dehesa, and feed exclusively on acorns and aromatic herbs. 

Dehesa is a rare ecosystem where at least ten oaks grow on one hectare. Let's find out what trees are involved and which acorns are actually eaten by the Iberian pigs. 

There are three types of oak trees in the dehesa. Two of these are very common in the Mediterranean climate - the cork oak (Quercus suber) and holly oak (Quercus ilex). The third type is the common English oak (Quercus robur), which you can often see in the UK forests.

The Cork Oak

The Cork Oak is a protected tree that grows to a height of about 12 m. Sometimes in the wild of the western Mediterranean (Iberian Peninsula and North Africa) it can reach up to 20 m. 

It is an evergreen tree that needs calcareous soil and plenty of sunlight to live. The bark of this tree can be up to 13 cm thick and is thus greatly protected against forest fires. Due to its unique properties (thermal and sound insulation, damping properties) it is highly valued, as it is used to make natural cork, which is used in many industries (viticulture, construction, aerospace). 

The tree is able to regenerate the bark on a regular basis, which is used for frequent harvesting on cork plantations. Cork oak grows slowly for most of 150 to 200 years, but there are also 500-year-old individuals in the world. 

The first extraction of cork from a tree is a quarter of a century after its planting. After that, the harvest is regularly repeated in the summer months about every 9 years without damaging the tree. 

Continuous regeneration of the bark plays another important role, as it actively contributes to reducing global warming. It absorbs carbon oxides from the air many times more than other trees. The acorns are up to three cm in size, and cork oak itself and its fruits are vital for two hundred species of migratory and hibernating animals.

The Holm Oak

The Holm oak is an evergreen tree up to 25 m tall, also growing at moderate altitudes around the Mediterranean. Here it used to form the main part of today's mostly felled forests.

Its bark is gray and silver colour. Due to low frost resistance, it is quite rare in Central Europe. It can live on various soils for more than 700 years, where it can easily overcome long droughts.

Its roots can find water deep in the ground, which is why it is so often planted as a hardy tree in many southern European cities. Here it manages a strong accumulation of summer heat, long months without rain and numerous paving.

In the past, its hardwood was used for building ships, beams and making barrels, carpentry tools or handles. Today, people benefit especially from its fruits. One and a half to three cm acorns serve as food for both livestock and wildlife.

The acorns were also used by humans to make flour, and the custom of grinding fruit remains as a coffee substitute to this day. Under the fallen leaves, which are hard and leathery on the tree, fungi thrive. The Holm Oak is thus one of the three essential trees for the occurrence of truffles.

The Common Oak

The Common English Oak with a massive crown reaches up to 50 meters and lives up to 2,000 years. Its occurrence is natural in warmer regions throughout Europe, Asia and the Caucasus. 

The Common Oak is extremely wind resistant. It has long roots, so it is usually planted where it is necessary to strengthen the soil, eg on the dam of a pond. On the other hand, the roots can connect to groundwater, which leads to more frequent lightning strikes than other trees. 

The leaves and bark off the summer oak are rich in tannins, which is used mainly in phytotherapy. There, the bark is used to treat various skin diseases and rashes. The bark is peeled especially young and smooth (ie from branches with a maximum diameter of about 15 cm), preferably in spring before the leaves sprout. 

In the past, the bark was also used in dyeing and leather tanning. The wood is hard, strong, heavy and characterized by high durability. It easily withstands changes in humidity and the effects of the weather, fossils during long-term immersion under water (it does not rot due to its high tannin content) and is resistant to pests. 

The wood is used in many areas like shipbuilding (this is one of the main reasons why these trees were literally decimated in Spain), in construction (especially for water structures such as mills), but also in the production of furniture, wood coal, sleepers, barrels, parquet, etc. 

The acorns, which grow up to almost four cm, are an important part of the winter diet of most animals that live in the woods. The Iberian pigs love these and eagerly look for them in the dehesa.

HOW DOES DRY-CURED HAM BECOME "DE BELLOTA"?

In order for the jamón to be given the exclusive lable "de bellota", the Iberian pig must be fed exclusively these acorns and aromatic herbs during the Montanera period between September and March.

Animals at the beginning of grazing weigh between 92 and 115 kg. In order to receive a "de bellota" tag, they must gain a minimum of 46 kg during the installation. 

Every year, the breeders face the difficult decision of how many animals can be let into the oak grove so that all of them reach the required weight and at the same time reach the maximum potential of these dehesas. 

One of the favourite old sayings is estimating the success of the season from onion. In any case, at least two hectares of paddock must be taken into account for each animal, which is of course reflected in the price of the final product.