xt7cjs9h5k3w https://exploreuk.uky.edu/dips/xt7cjs9h5k3w/data/mets.xml   Kentucky Agricultural Experiment Station.  journals kaes_circulars_004_617 English Lexington : The Service, 1913-1958. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Circular (Kentucky Agricultural Experiment Station) n. 617 text Circular (Kentucky Agricultural Experiment Station) n. 617  2014 true xt7cjs9h5k3w section xt7cjs9h5k3w • ·- - I ~   _A   ·$ < E ’
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Circular 6I7 • By W.Y.V¤mey
UNIVERSITY OF KENTUCKY
COOPERATIVE EXTENSION SERVICE
AGRICULTURE AND HOME ECONOMICS

    
Curing ond Agmg Country-Style Homs
   
Under Controlled Condntnons
By W. Y. VARNEY
The flavor of country-style (dry-cured) ham is much preferred
by many people over that of the conventional pumped ham. Pro- -
duction of this type of ham can be a profitable business, if it is
done systematically. There is little doubt that consumption of
this product will increase substantially as uniformity of product is
attained. This is done by curing and aging the hams under con-
trolled conditions.
“Controllcd conditions” means curing under refrigeration and
mechanically controlling the temperature and humidity of the
aging room. Controlling humidity requires installation of a heating
unit (installed in such a manner as to avoid the consumption of
the oxygen of the room), a humidifying unit to add moisture
when needed, and a cooling and dehumidifying unit to remove
moisture when needed. An exhaust fan is needed for use after
fumigation and a number of circulating fans are needed to provide ‘
good air movement in all parts of the room at all times. r '
The required equipment and proper insulation and moisture-
proofing of thc building are expenses that you would not have
in aging hams under natural conditions. However, when you
consider that shrinkage is reduced and loss through spoilage is T
minimized. the added expense does not seem so much. Further-
more, the inventory is turned about three times as fast under
controlled conditions as under natural conditions.
Although building plans are available, it is felt that construc-
tion arrangements should be worked out on an individual basis be-
cause needs vary, depending upon the size of operation, individual
preferences. and existing facilities.
It is strongly urged that a sound program be developed and
followed to minimize the risk of loss and to insure a uniform product.
ln this. as in most enterprises, experience is invaluable in assuring
success. Therefore. do not make an extensive investment until
you have gained some experience.
2

 Selection and Delivery of Hams
( 1. Select meaty, short—cut hams. The short-cut ham is much pre-
ferred over the old fashioned long-cut ham because it allows
the consumer more edible meat per dollar spent and is easier
to handle in curing and aging. Regular (skin on) hams should
be used if they are to be sold whole, while skinned hams may .
be preferable if they are to be sliced and packaged.
2. Hams should be sufficiently chilled but fresh. They should be
placed in cure not later than three days after kill. Spot-check
_ the internal temperature of the hams when they are received
from the packer. The temperature should be 38°-40°F. Do not
pack or stack them if the internal temperature is above 42°F
and do not accept them if it is above 45°F.
Curing Mixture and Application
The basic curing ingredient, of course, is salt. To this, sugar is
added for enhanced flavor and a softening effect, and saltpeter as a
color fixing agent. The latter may be either potassium nitrate
(KNO3) or sodium nitrate (NaNO3). Other ingredients such as
pepper, molasses, etc. are sometimes used, but these represent
an additional expense and are of questionable value. In fact, many
people feel that they detract from the appearance of the hams.
‘ It is suggested that at least 6% but no more than 7 pounds of
' salt be used per 100 pounds of hams in shelf-curing. It is important
that spoilage be avoided, of course, but it is also quite important
that excessive saltiness be avoided. Keep in mind that too much
sugar tends toward slime production. It is suggested that 1%
( pounds of sugar per 100 pounds of hams be the upper limit. At
least 2 but no more than 3 ounces of saltpeter should be used per I
100 pounds of hams.
Suggested Mixture
100 lb salt (medium Hake)
20 lb sugar (white)
2lb saltpeter (granulated)
Use 8% pounds of the mixture for each 100 pounds of hams.
Use 60 percent for the first application and the remaining 40
percent 10 to 14 days later, depending upon the penetration of
the initial application.
3

 Alternute Mixture
100 lb salt (medium flake)
10 lb sugar (white)
2 lb saltpeter (granulated)
Use 7 pounds of the mixture for each 100 pounds of hams. Use
60 percent for the {irst application and the remaining 40 percent
10 to 14 days later, depending upon the penetration of the initial
application. More even distribution of salt may be attained and
slime development retarded by rubbing the remaining pockets of _ _
the curing mixture over the hams about 10 days after the last
application.
Curing Schedule
The temperature of the curing cooler should be maintained
at as near 38°F as possible. It should not be below 36°F nor above
40°F. The relative humidity should be 75 to 80 percent.
The hams may be cured on wooden shelves, but it is advisable
to cover each shelf with a sheet of polyethylene. Stacking should
be done so as to provide the greatest utilization of space. Hooks
should be covered by other hams as much as possible. This keeps
them moist, which provides better salt penetration and therefore ·
is an aid in preventing spoilage. ~
One side of the shelves should be elevated slightly to allow
drainage. It is advisable to arrange the shelves so that the hams
on higher shelves do not drain on those below.
The hams should remain in cure approximately 40 days. They V
should then be washed thoroughly. Use a scrub brush and change
the water often enough to keep it clean. They probably should
be soaked 2 to 4 hours if smoking is to be done.
After washing, and soaking if this is to be done, place the hams
in stockinettc. The hock-ends may be up or down. There are
advantages and disadvantages both ways. Be sure that no water
remains in the hocks if they are to be tumed up. It may be ad-
visable to hang the hams on a rack and dry the surfaces with a
fan before placing them in the salt equalization room.
The temperature in the salt equalization room should be main-
tained at 50°-55°F and the relative humidity at 60-65 percent.
Some air movement should be provided in all parts of the room.
4

 The hams should be hung on racks so that they do not touch
each other. They should remain in this room at least two weeks.
When considering the refrigeration and dehumidification equip-
ment requirements for the salt equalization room, it should be .
noted that water equivalent to approximately 10 percent of the
weight of the hams must be removed from the room. The need
for a good vapor barrier for walls, ceiling, and Hoor is also em-
phasized.
Smoking
It is not essential to smoke your hams. However, most people
feel that smoking adds substantially to the attractiveness of a ham
and it also serves as an anti-oxidant (prevention of excessive
rancidity).
If hams are to be smoked, this may be done immediately after
removal from the salt equilization room. However, they may be
moved directly to the aging room and held a few days or even a
few weeks prior to smoking if this is more convenient or desirable
for you. Smoke at a cool temperature (80° if possible and certainly
not to exceed 9()°) until a pecan—like color is developed. Do not
· smoke the hams to an excessively dark color.
Aging
The temperature in the aging room should be maintained at
V '70‘°-75°F and the relative humidity at approximately 65 percent.
Heating, cooling, and dehumidifying equipment is needed. Humidi- '
fying (moisture adding) equipment may be desirable in winter.
Do not install heating equipment that would consume the oxygen
in the room.
An exhaust fan should be installed at an end or on a side of
the room for use after fumigation. Air intake openings near the
floor are also needed for this. A sufficient number of circulating
fans should be used to provide some air movement in all parts
of the room. This helps to prevent mold growth.
The hams should be hung on racks so that they do not touch
each other. It is recommended that they remain in the aging
room at least three months but not more than four months before
sale.
5

 Summory of Conditions ond Times
in Curing ond Aging
Relative
Temperature Humidity Time
Curing cooler ...................... 38OF 75-80% 40 days
Salt equalization room ...... 50°-55°F 60-65% 2 weeks
Aging room ........................ 70°-75°F 65%   months i
Sonitotion
Cleanliness is the First line of defense against spoilage, slime
development, etc., so a good sanitation program must be followed ·
consistently.
\Vash bins, shelves, etc. thoroughly with a good detergent and
water and rinse thoroughly with clean water before placing a
fresh batch of hams in cure. Practice periodic cleaning of curing
room walls and Hoor. Use clean utensils. If there is any doubt at
any time about the cleanliness of any item, wash it!
Protection from Insects
Insect infestation can he very costly and may be disastrous if
proper control measures are not used consistently. The most com-
mon pests are given below;
Skipper (Piophila cusei L.) I
The eggs are laid by a small, two-winged Hy which is about
half the size of the housefly. The eggs hatch in about 36 hours into
small, cylindrical, white maggots which are called "skippers" be-
cause of their leaping power. The larva completes its growth, under V
favorable conditions, in T to I0 days. Then it moves to some dry
spot. contracts in length, and becomes yellowish. The outer skin
separates from the body and gradually hardens and darkens into
a golden brown. This resting stage lasts about I0 days, when the
adult insect. the Hy, emerges. The Hy lives about I0 days in the
summer. Its entire life cycle may be concluded within 3 weeks.
under favorable conditions.
The smallness of the Hy requires that the room be screened
with 30 to 32 mesh screen. The Hy is not active at night but is able
to perform its life work in a partially darkened room. It does not
often attack fresh meat or meat that has been salted and not smoked
6

 but the odor of smoked meat attracts it. The larvae feed on the soft.
lean tissue of the meat and are referred to as deep feeders.
Red-Legged Hum Beetle (Necrcbis rufipes De G.)
This beetle is rather slender and of a dark bluish color, with
_ reddish legs. The larva is a slender grub, covered with scattered
hairs. At first, it is white with a brown head and two small hooks l
at the end of the body. As it matures it becomes darker, and when
full-grown it is grayish white with a series of brown patches above.
The life cycle may be completed in 45 to 50 days. This beetle ap-
. pears about the first of May. The larvae usually eat the fat near
the surface and so are referred to as surface-feeders.
Lurder Beetle (Dermestes Iurdarine)
This beetle is dark brown with a yellowish-brown band across
the front half of its wing covers. On the band are six black dots,
three on each side of the middle line. The larva is small, brown,
hairy, and has two short, curved spines on the top of the last
abdominal segment. Its habits are similar to those of the red-
legged ham beetle.
Cheese or Hum Mite
This mite is whitish at first, with six legs, but the adult has
· eight. It is so small that it can barely be seen by the naked eye.
. It frequently attacks hams, eating great holes in them and leaving
material of a powdery consistency. Infestation may be detected
by the presence of this material on the surface around the aitch
bone. It is sometimes mistaken for mold. It seems that the longer
· hams are aged. the more susceptible they become to infestation
by this pest. I
Blow Fly (Ca/Iiphoridae)
There are several species of this Hy and they vary in size from
that of a housefly to two or three times as large. The adult Hy
is metallic blue. metallic green, coppery green, or greenish black
according to the species. The larva (maggot) is white and varies
in length from extremely small to onc—half inch or longer. The egg
hatches in one to two days. The developmental stage, from egg
to adult, is 16 to 35 days and averages about :22 days. The adult
Hy lives about 35 days.
This pest lays its eggs on hams and seems to prefer those that
7

 i
are fresh or nonaged. However, the possibility of infestation in aged
hams should not be ruled out. The larva feeds for three to nine
days, eating large holes in the ham and creating a disagreeable odor.
Control Measure
Screen all openings with 32-mesh screen. Follow a regular
schedule of fumigation. Methyl bromide is a good fumigant for
this purpose. It is available in one-pound cans or larger units. Use r
the application apparatus prescribed by the methyl bromide sup-
plier. This is a “must” for safety.
Mount the part of the apparatus in which the methyl bromide
can is seated and opened on a wall outside the aging room. Extend
a plastic tube through the wall to a point near the center of the '
room and about two feet from the ceiling. Connect the tube to a
piece of %-inch x 4-foot perforated copper tubing with the terminal
end closed. The copper tubing should be placed in a 4" x 4" x 4’
galvanized pan. The perforated copper tubing and the galvanized
pan prevent liquid methyl bromide from dripping on the hams.
The tubing and pan will not come with the other part of the ap-
paratus and will need to be made to order.
Before beginning the fumigation, close all openings tightly. This
should be done from the outside to avoid the necessity of entering
the room while it is filled with gas. Lock the doors and post warn-
ing signs. Have an exhaust fan switch located outside the room.
Have one or more circulting fans located on the floor and turned ,
upward during fumigation as methyl bromide is heavier than air A
and will settle too quickly without mechanical circulation.
Use two pounds of methyl bromide per 1,000 cubic feet of space.
Allow ample time for dispersion of the material from the can be-
fore another can is used. The chemical changes from a liquid .
state in the can to a gas in the room. Allow the gas to remain in the
room approximately 24 hours, then open the vents near the floor
and turn on the exhaust fan. Run the fan at least one hour before
entering the room.
If infestation is discovered, fumigate three times at 5-day
intervals. Do not fumigate if the temperature of the room is
below 65°F.
Agricultural and Home Economics Extension Service of the University of Kentucky,
the United States Department of Agriculture cooperating. W. A. Seay, Director. Issued
in furtherance of the Acts of May B and June 30, 1914. 3M_1_67