An Improved Preservative Skin or Covering for Hams, Bacon, Cheeses, and other Provisions.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
An Improved Preservative Skin or Covering for Hams, Bacon,
Cheeses, and other Provisions.
I, JOHN MITCHELL, Merchant, Barnsley, Ayr, a Partner of the Firm of Walter
Mitchell & Sons, Provision Merchants, Exporters and Importers, Main Street,
Ayr, do hereby declare the nature of this invention to be as follows:-
The invention consists in being a new improved simple and effective skin or
covering for hams, bacon, cheeses and other provisions for home and foreign
use, and specially for export to distant countries. This preservative skin or
covering is obtained by the following process in which tissue paper, netted cotton,
bone gelatine, alum and water are all used. The bone gelatine is converted
into a hot liquid, and while in a boiling state is mixed with boiling alum and
water in certain proportions. The ham, cheese or other article which is first
enveloped in a sheet of tissue paper and then wrapped in netted cotton is there-
upon dipped in the boiling gelantiseptic liquid and then taken out and allowed
to cool and dry when it is found that a very light antiseptic preservative glazed
skin covering has formed round the article to which it does not stick or adhere
owing to the stringent properties of the alum; and further as the skin excludes
the air and all decomposing elements or insects and resists any atmospheric or
climatic conditions it has proved a perfect preservative and an invaluable cover-
ing for export to distant countries such as West Indies, Africa &c. preserving
as it does the flavour moisture and perfectly fresh condition of the article, and
thus superseding in simplicity and effectiveness any previous form applied for
the purpose.
An Improved Preservative Skin or Covering for Hams, Bacon,
Cheeses, and other Provisions.
I, JOHN MITCHELL, of Barnsley, Ayr, Scotland, Bacon Curer, do hereby declare
the nature of this invention and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement:-
My invention relates to an improved preservative skin or covering for pro-
tecting hams, bacon, cheese, sausages and the like whether in the cooked state
or mildly cured or otherwise, and which will be effective even in tropical coun-

page_text: tries where owing to the heat and the extreme moisture present in the atmosphere
it becomes extremely difficult to retain such goods in the proper condition.
My improved covering provides an air-tight skin excluding all elements of
decomposition or insects, and resistant to atmospheric or climatic conditions,
and has proved a perfect preservative especially for goods to be exported to
distant countries inasmuch as it not only preserves but even improves the flavour
and condition of the article. The preservative skin or covering of my invention
may be prepared in various ways to meet requirements of special cases, but in
general the manner of preparing the same preferably adopted by me is as
follows:-
:-
I take thirty pounds of clean, fresh, dried bone gelatine and melt it by the
application of heat in the usual manner. I further prepare a saturated solution
of one and a half pounds of pure pulverised alum in hot water; I further procure
about two gallons, say twenty-four pounds of skim milk or butter milk, finally,
I may add a little harmless colouring to suit requirements. The above ingre-
dients are then thoroughly incorporated at a temperature of about 140° F.
The ham or the like is then carefully encased in grease-proof paper; it has then
drawn over it a thin netted cotton bag which must be twisted until it is thoroughly
tight and be tied up where loose with twine, and the ham be strung by aid of a
needle in the usual way. After this covering the ham is dipped in the hot
solution above described and allowed to remain beneath the surface of the
solution until all air bubbles disappear. It is then withdrawn, hung up for
a few minutes, then re-dipped in the solution, but not allowed to remain therein,
and finally hung up in a drying room and subjected to a current of hot dry air
from a fan for from six to eight hours. The effect of this procedure is to coat
the ham with a waterproof and airproof skin or covering, and in order to finish
it satisfactorily and give it a polish I take a sponge or soft cloth and apply
therewith a little of the following solution:-
From two to three ounces of lacterine or milk caseine dissolved in half a pint
of liquid ammonia of ordinary pharmaceutical strength. This preparation imme-
diately dries on the surface of the skin and so confirms and gives it the required
gloss. An alternative preparation for dipping the hams is as follows:-
Thirty pounds of gelatine dissolved as before, about two and a half gallons
of lactic acid solution or of slightly soured whey, and one and a quarter pounds
of alum dissolved in hot water as before. The above proportions are given by
way of example and may be varied, moreover, if milk or whey cannot be had
a sufficiently resistant coating can be made by the aid of hot water alone, but
I prefer the mixture given above. If it be necessary to render the skin more
pliable after drying and prevent any tendency to crack a small quantity of
glycerine may advantageously be added to the composition above described. I
find this unnecessary wherever the article prepared is of a greasy or soft nature
such as certain sausages for instance, but for hams or the like which are to be
hung up for a long time the addition of a little glycerine, say about half a pound
to every sixty pounds of the preparation should be made. The alum solution
when properly prepared will weigh about six pounds, being one and a quarter
pounds alum to four and three quarter pounds hot water. The proportions
given in the first instance set forth above produce about sixty pounds of the
liquid having a density of 18° of the Twaddell hydrometer. It will be obvious
that the successful carrying out of the operation depends on the care with which
the composition is prepared, and also the avoidance of any leakage or faulty
parts whereby air can obtain access within the artificial skin thus produced on
the surface of the ham or the like. In the case of a ham which has been properly
coated and has been kept for a considerable time, the coating is found to become
still more closely adherent to the substance of the ham, and to such an extent
is this the case that even the piercing of the same by a testing spear or the like
will not injure the goods, nor cause the subsequent admission of anything which
affects the contents,

page_text: A further advantage of my protective coating herein described is found in its
great simplicity and ease of application and its entire freedom from harmful
substances which might affect the quality of the goods.
The process is equally applicable to both raw and cooked provisions. In
certain cases I may even dispense with the paper and woven coverings and rely
solely upon a coating of the solution substantially as above described.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1. A waterproof composite coating for hams, bacon, sausages and cheese, con-
sisting essentially of an inside layer of waterproof paper or fabric, an outer layer
of textile fabric and a non-hygroscopic indurated coating of aluminated gelatine
with or without admixture of milk, whey, glycerine or other emollient substances
transfusing and uniting the whole firmly together and forming a waterproof
and airproof coating, substantially as described.
2. The improved preparation for dipping hams and the like for the purpose of
rendering them proof against decomposition, airproof, and waterproof, substanti-
ally as hereinbefore described.
3. The improved preparation for glossing hams and the like coated as herein-
before set forth, consisting of caseine dissolved in liquid ammonia, substantially
as and for the purpose described.
Dated the 14th day of June 19.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.