IMPROVEMENTS IN CURING BACON
Year: 1871

page_text: LETTERS PATENT to William Henry Prossor, of Tralee, in the
County of Kerry, Ireland, and John Vincent Slattery, of Wel-
lington Chambers, High Street, Borough, in the County of Surrey,
PROVISIONAL SPECIFICATION left by the said William Henry Prossor
and John Vincent Slattery at the Office of the Commissioners of
Patents, with their Petition, on the 7th August 1871.
We, WILLIAM HENRY PROSSOR, of Tralee, in the County of Kerry,
Ireland, and JOHN VINCENT SLATTERY, of Wellington Chambers, High
Street, Borough, in the County of Surrey, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN CURING BACON," to be as
follows:
:―
This Invention has for its object improvements in curing bacon.
For this purpose we proceed as follows:-After the pigs are killed and
the sides are separated we inject into them by means of a puncturing

page_text: instrument and a force pump (such as are now used for injecting with
brine) a concentrated solution consisting of sulphite of soda or other
alkaline sulphate and nitrate of soda mixed with the pickle which runs
from the bacon in salting.
:
The following quantities are sufficient for injecting twenty sides of
bacon Sulphite of soda or other alkaline sulphate, 8 oz.; water,
20 oz. nitrate of soda, 40 to 60 oz.%; water, 60 to 80 oz. The salts
are dissolved and the solutions mixed and filtered. Sufficient carbonate
of soda is then put in to make the solution neutral or slightly alkaline,
and 15 to 20 gallons of strong pickle such as runs from the bacon in
salting is then added and the mixture is ready for use. After the in-
jection the bacon is salted with salt and saltpetre and prepared for the
market in the ordinary way.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Henry Prossor and John Vincent Slattery
in the Great Seal Patent Office on the 6th February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
HENRY PROSSOR, of Tralee, in the County of Kerry, Ireland, and Joun
VINCENT SLATTERY, of Wellington Chambers, High Street, Borough,
in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of August, in the year of
Our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her beirs and successors,
give and grant unto us, the said William Henry Prossor and John
Vincent Slattery, Her special license that we, the said William Henry
Prossor and John Vincent Slattery, our executors, administrators, and
assigns, or such others as we, the said 'William Henry Prossor and
John Vincent Slattery, our executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN CURING BACON," upon the con-
dition (amongst others) that we, the said William Henry Prossor and

page_text: John Vincent Slattery, our executors or administrators, by an instru-
ment in writing under our or their hands and seals, or under the
hand and seal of one of us or them, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that we, the said William Henry Prossor and
John Vincent Slattery, do hereby declare the nature of the said In-
vention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement
thereof, that is to say :-
This Invention has for its object improvements in curing bacon, and
consists in the quick curing of bacon by the injection of the meat by
means of a force pump with solutions of sulphite of soda or other
sulphite of an alkali in conjunction with nitrate of soda and pickle or
brine. By this risk of taint is avoided, icc economised, much less room
required for working, and the cure perfected in about one half the time
that is necessary to manufacture bacon by the methods in ordinary use.
The pigs after being killed and the viscera removed are hung in a well-
ventilated room known as the hanging house, the sides separated by the
animals being cloven down the back, and the backbone and head
removed, as is done in the ordinary method of preparing pigs for the
manufacture of bacon. For this quick curing process the temperature
of the hanging house requires attention. We prefer that it should
not be lower than 46° Fahrenheit, and if possible not higher than 56°
Fahrenheit; neither should too strong a current of air be allowed to
play upon the sides. After remaining in the hanging house for any
convenient length of time, not less than ten hours and not exceeding
twenty-four, the sides are ready for the process of cutting, which is
performed in similar manner to the ordinary method, and consists of the
removal of the feet, certain bones, offal, and scraps of meat, preparatory
to transferring the sides to the curing room. The sides arc then taken
to the curing room or cellar, and, if the fat is moderately firm, are ready
to be injected with the prepared pickle. The sides being laid on the
floor or tables are injected by means of a force pump, a hose, and a
perforated needle similar to and used in the same manner as those
employed in the ordinary method of curing bacon.

page_text: The pickle to be injected is prepared in the following manner :-For
each ten pigs in the number to be injected take of sulphite of soda or
other of the sulphites of the alkalies six to nine ounces avoirdupois,
nitrate of soda forty to sixty ounces. We consider sulphite of soda the
most preferable in every way for this process, but sulphites of other
alkalies may be used in a similar manner. Dissolve these salts separately
each in as small a quantity of water as possible; strain or allow the
solutions to settle. To each solution add about a drachm of a saturated
solution of sub-carbonate of soda, or sufficient to neutralize or even
render the solutions slightly alkaline, then thoroughly mix the clear
liquids together. The solutions of sulphite of soda and nitrate of soda
both being neutralized will keep separately without deterioration for
many days, and can be made to suit convenience in quantities, but had
better not be mixed together until within a few hours of being used;
then take a quantity of brine or pickle sufficient for the injection of
ten pigs in the ordinary method of curing, which quantity may be at
discretion so long as it is equally distributed among the ten pigs, and so
long as there is quantity enough to inject them plentifully. To this
quantity add the above combined solutions, mix them intimately, and
then inject ten pigs with the prepared pickle in the same manner as pigs
are injected in the ordinary method of cure, using the whole quantity
of the prepared pickle and as quickly as possible; this process to be
repeated for each ten pigs. The pickle employed with the preparation
for this quick cure may be such as is used for injection in the ordinary
method of cure. It may be either a saturated solution of salt in water
in which some saltpetre has first been dissolved, or may be the brine
which falls from bacon during the process of salting. Should the latter
be employed the patentees recommend that it should be well cleared and
fined by straining and settling, and used as fresh as possible, the old
and surplus pickle thrown away, and only the newest pickle employed
for the prepared injection. As pickle which flows from meat which has
been injected with the preparation will sometimes contain traces of the
sulphite employed, with such it may be necessary to use one-eighth part
less of the sulphite. This must only be determined by analysis or
observation of the bacon, the effect of an excess of sulphite being to
render the color of the lean meat pale. In using any pickle it is
necessary to avoid employing for the preparation that which shews any
signs of acidity. The quantity of sulphite to be used in the first place
is to be determined by the condition of the pigs when killed, and also by

page_text: the temperature of the weather. The less tired the pig is when killed,
and the more favourable the temperature for curing, the less of the
sulphite is necessary. If the bacon is too deep a color a smaller quantity
of nitrate of soda can be used.
It is necessary when injecting the prepared pickle to be careful that
the fat is firm but that the lean is soft. In very warm weather the
quickest way to insure proper condition will be to hang the sides after
cutting in a very cold chamber, such as is sometimes done in the
ordinary method of curing, for a short period sufficient to harden the fat
but not the lean. In very cold weather an artificial heat might be
advantageously employed to soften the lean, but neither is absolutely
necessary, as a short delay in the curing room before injection in hot
weather, and not allowing the sides to remain long in the hanging house
in cold weather, will render them fit to be worked. We prefer in warm
weather a mean temperature of 50° F., that is, from 48° to 52° in the
curing room; and in cold weather a mean temperature of 52° F., that is,
50° to 54°. If the sides have the fat and lean in proper condition, that
is, the fat firm and the lean soft, a temperature of 51° F. will be found
the most advantageous at all times, but the process can be safely
used several degrees higher. We consider it injurious to the result to
inject the meat while the fat is very soft, and also injurious to allow the
lean to become hardened before injection, as the former is likely to
injure the color and texture of the fat, and the latter does not allow the
prepared pickle to penetrate quickly the fibre of the meat.
After being
injected with the prepared pickle the sides are then ready to be imme-
diately salted, which is to be done according to the ordinary method by
sprinkling them with saltpetre, and laying them one above the other
with staves or boards and layers of salt between them. The piles may
be higher than they usually are in the ordinary method; they may
consist of fourteen or sixteen sides each for this quick cure. The sides
are to remain undisturbed in the piles for about six days, after which
they are to be removed, the salt that remains on them thrown off, and
the sides again piled up one above the other without either salt or'
staves, care being taken to place the sides which have been uppermost
during the six days salting in the lower part of the piles when put up
for the second time, thereby reversing the piles. They should remain
in this position for at least twenty-four hours, after which they are ready

page_text: to be cleaned and prepared for use, or packed for export in the ordinary
manner.
Having thus described the nature of our said Invention, and the
manner of performing the same, we would have it understood that we do
not confine ourselves to the exact details described; but we claim the
curing of bacon by the use of sulphite of soda or other sulphite of an
alkali in the manner substantially as described.
In witness whereof, we, the said William Henry Prossor and John
Vincent Slattery, have hereunto set our hands and scals, this
Twenty-second day of January, in the year of our Lord One
thousand eight hundred and seventy-two.
WILLIAM HENRY PROSSOR. (L.S.)
JOHN VINCENT SLATTERY.
(L.S.)