the montanera
To create a fine acorn-fed Iberian ham, there is an essential phase: The Montanera.
During the initial months of the Iberian pig's life, it is fed with fortified feed until it reaches around 100kg in weight. This helps to develop a strong animal with sufficient bone structure to endure the final fattening stage.
In November, when acorns naturally fall due to their optimal ripening point or the effects of typical seasonal rains and winds, those Iberian pigs that meet these conditions are let out to graze in the "dehesa".
Over the following 4 months (November to February), they will consume about 1kg of acorns daily, along with wild herbs, fruits, and whatever they find in the fields. They will move around a lot, which will increase their muscle mass and infiltrate more fat into the muscle, resulting in those characteristic white streaks.
By the end of those 4 months, they should have increased their weight by 50%. So, if they started at 100kg, they should weigh 150kg. At this point, they are ready to become magnificent acorn-fed Iberian pigs. If they don't reach the indicated weight, according to the recent Iberian pig regulations approved by the Ministry of Agriculture, they must be labeled as campo-reared ham (formerly called "recebo").
Do all pigs go out to the montanera?
No, firstly, only Iberian pigs are allowed to graze. Before starting the Montanera, the shepherd must calculate the amount of acorns available that year, determining how many pigs need to be let out so that all of them reach the necessary weight to qualify for producing excellent acorn-fed Iberian ham.
The rest will be solely fed with feed throughout their lives.