Year: 1894

page_text: Date of Application (in United Kingdom), 16th May, 1894
Complete Specification Left, 16th May, 1894-Accepted, 5th Jan., 1895
I, HARALD EMIL HANSEN of 274 Rando Street, St. Paul, Minnesota, United
States of North America, Pharmaceutical Chemist, 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:-
Two modifications of cheese may, as is well known, be produced from milk viz.: an
insoluble and a soluble. The insoluble modification is produced by adding rennet
material to the milk, whereby the cheese material is separated out which is a usual
article of commerce known under many different names. The soluble modification
which is produced by adding a small amount of acid to warmed milk, is the
material which by the method here in question is used for producing condensed
milk. The keeping qualities of condensed milk depend, as is well known, upon the
temperature to which the milk may be heated during the sterilization. As the
condensed milk produced according to the method here in question may be heated
to beyond 120° C. and nevertheless retain its white colour and its taste it will keep
better, taste better and look better than condensed milk heretofore produced.
The process is as follows. Whole milk is deprived of its creain by preference
by the aid of a separator. The separated cream is then placed in a cold place.
The skimmed milk is put into a usual cheese vessel, heated to 60° C. and has a
little acid added to it whereby the cheese material in the course of a few minutes
separates out. The cheese material is freed from the whey which runs off easily
by opening a hole in the vessel. The cheese material remaining is rinsed with cold
water until it has quite cooled down, whereupon it is pressed gently in a cheese
press and passed through a sieve of galvanized iron wire. The cheese material
thus finely divided is now put into the cheese vessel again and mixed well with a
dilute solution of potash or other alkali. This mixture must be left standing well
cooled in the cheese vessel for some hours, for instance from evening till morning.
It is then carefully heated while being stirred whereby the mass gradually becomes
thick fluid. To this is added, from time to time and while stirring, the cream that
had been taken away from the milk. The mixture is the condensed milk which
after being well cooled is put into tins which are at once hermetically closed.
The tins thus closed are placed in an iron basket which is placed in a solid iron
vessel or in an iron boiler provided with double walls and containing a little water
whereupon the whole is closed with a tight iron lid which is provided with a
thermometer and a tap. This done steam is from time to time admitted through
a steam pipe leading to the iron vessel or boiler. The tins are now heated to a
temperature of 118 to 124° C. as desired, and after the lapse of an hour the steam
[Prine Rd

page_text: is shut off and the tap is opened for letting off the steam around the tins. The lid
is then removed and the tins taken out and cooled in a cold space. They are then
ready for use.
.
The process in question is as will be seen different from other methods in which
the water is removed by evaporation in a vacuum or in which sugar or other
preserving agent is used.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
The method of producing condensed milk characterized thereby that the milk is
separated from the cream whereupon the cheese material is separated out in
insoluble form by addition of acid, which cheese material, after that the whey has
been removed, is mixed with a thin alkali solution and is through heat and agitation
after some time rendered fluid again and is mixed with cream in order that the so
condensed milk after having been put into hermetically closed tins shall be able to
be sterilized by heating in the ordinary manner.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.