A capon refers to a rooster that underwent a castration. Capons are generally seen as a delicacy and old fashioned kind of food. Castrating a rooster does have an effect in the meat. Capon meat is considered more tender and more flavorful and has a higher fat content. The flavor difference between regular and capon meat is distinctive enough that consumers can immediately tell the difference once they have tasted it, especially if the capon has been cared for well enough.
Because of the commercialization of poultry raising, finding a capon can become quite difficult. One of the ways a consumer can get a capon is if he knows a quality butcher a small farm. Despite the extra effort in sourcing a capon, many gourmands are of the opinion that the extra work is worth the effort.
Turning a rooster into a capon is called a caponization. The whole caponization procedure happens when the rooster is between six and twenty weeks of age, though this really depends on the farmer and the chicken breed to be used. What the farmer does is to remove the testes of the rooster through a surgical procedure. But large scale producers often caponize their roosters through the use of hormones by implanting them with estrogen. Whether surgical or hormonal though, the end result is halting the production of sex hormones that roosters develop.
The effect of caponization on roosters is to make them mellower. They lose their aggressive behavior, which makes them easier to handle. The absence of the hormones also changes the meat and how it matures. It becomes more tender and fatty. It also tastes less gamy.