Dry-Cured Ham 355Ripening - Drying
There are two main objectives for this stage:
(1) to dry the hams till they reach about 32%
of weight loss, and (2) to provide enough
ripening time for enzymes to react and con-
tribute to fl avor. This stage, therefore, is very
important for the fi nal quality of dry - cured
ham, and the conditions in the drying chamber
must be controlled and verifi ed. A typical
view of hams in a drying chamber is shown
in Figure 20.3. Air speed, temperature, and
relative humidity are usually computer -
controlled in modern drying chambers, but
they must be checked periodically. Water has
to diffuse from the inner part of the ham to
the surface and then it is evaporated to the
chamber environment. Both rates, diffusion
and evaporation, should proceed in a similar
fashion. Thus, an excess of evaporation,
when the relative humidity has a lower value
than normal, may cause excessive evapora-
tion on the surface of the ham and produce
dehydration. A prolonged dehydration,
known as hardening, gives a dry, hard texture
and dark color to the external area of the ham
(Toldr á 2006b ). Once the ham has been
dehydrated in this way, it is very diffi cult to
get further diffusion of water to the surface.
Ripening and drying conditions are very
different for each type of ham and country,
and may also vary depending on the salt
content (Andr é s et al. 2005 ). Drying tem-
peratures normally range from 16 ° to 25 ° C,
depending on the processing time; longer
times require lower temperatures, with the
relative humidity between 65% and 80%.
The length of the process has large varia-
tions, from 3 to 36 months. Usually, at least
6 to 9 months of process are necessary to get
a ham of an acceptable quality. However,
those hams with better quality may have
several months of extended ripening. They
are covered with a layer of lard to prevent
further dehydration and allow a longer
enzyme action and more intense fl avor devel-
opment (see Fig. 20.4 ). The reduction inor hand - rubbed, and left for 2 – 3 weeks.
Typical amounts may be 20 – 30 g medium -
grain salt per kg on the lean surface and
10 – 20 g of wet salt per kg on the skin (Parolari
1996 ). In other cases, as in Spain, hams are
placed in large containers, fat side down, and
surrounded by dry salt (usually rough sea
salt), and time of salting is strictly controlled
to 1.1 day per kg (Toldr á 2002 ). Temperature
is kept at about 2 – 4 ° C and relative humidity
at 90 – 95%. Salting is shorter for thawed
hams in order to avoid an excess of salt
intake.
Hams experience a slight weight reduc-
tion due to moisture loss, about 3 – 4%, in this
stage. It is important to remove the excess
salt by rinsing and brushing the hams at the
end of this stage.
Post - Salting
The main goal is to equilibrate the salt and
nitrate content inside the hams. This stage is
also known as equalization. Salt and nitrate,
once they have penetrated into the ham, have
to diffuse to the inner area. Diffusion rate is
very slow and usually takes around 40 to 60
days, depending on the size of the ham, pH,
amount of intramuscular fat, and tempera-
ture. The temperature is kept below 6 ° C and
the relative humidity within the range of
80 – 90%; temperature may slightly increase
toward the last days of this stage. There are
some additional weight losses in this stage,
around 4 – 6%.
Smoking
The use of smoke is optional and depends on
the typical traditions and location (i.e., north-
ern countries). As a result, smoking is used
in short processes like American country -
style ham or German Westphalia ham. These
hams have a particular smoky fl avor. In addi-
tion, smoke compounds acted as a kind of
preservative due to their bactericidal effect
(Ellis 2001 ).