The following article was written by Albert Hoppin, editor of the
_Northwestern Miller_, at the request of Special Agent Chas. W. Johnson,
and forms a part of his report to the census bureau on the manufacturing
industries of Minneapolis.
"The development of the milling industry in this city has been so
intimately connected with the growth and prosperity of the city itself,
that the steps by which the art of milling has reached its present high
state of perfection are worthy of note, especially as Minneapolis may
rightly claim the honor of having brought the improvements, which have
within the last decade so thoroughly revolutionized the art of making
flour, first into public notice, and of having contributed the largest
share of capital and inventive skill to their full development. So much is
this the case that the cluster of mills around the Falls of St. Anthony is
to-day looked upon as the head-center of the milling industry not only of
this country, but of the world. An exception to this broad statement may
possibly be made in favor of the city of Buda Pest, in Austro-Hungary, from
the leading mills in which the millers in this country have obtained many
valuable ideas. To the credit of American millers and millwrights it must,
however, be said that they have in all cases improved upon the information
they have thus obtained.
"To rightly understand the change that has taken place in milling methods
during the last ten years, it is necessary to compare the old way with the
new, and to observe wherein they differ. From the days of Oliver Evans, the
first American mechanic to make any improvement in milling machinery, until
1870, there was, if we may except some grain cleaning or smut machines,
no very strongly marked advance in milling machinery or in the methods of
manufacturing flour. It is true that the reel covered with finely-woven
silk bolting cloth had taken the place of the muslin or woolen covered hand
sieve, and that the old granite millstones have given place to the French
burr; but these did not affect the essential parts of the _modus operandi_,
although the quality of the product was, no doubt, materially improved. The
processes employed in all the mills in the United States ten years ago were
identical, or very nearly so, with those in use in the Brandywine Mills in
Evans's day. They were very simple, and may be divided into two distinct
operations.
"First. Grinding (literally) the wheat.
"Second. Bolting or separating the flour or interior portion of the berry
from the outer husk, or bran. It may seem to some a rash assertion, but
this primitive way of making flour is still in vogue in over one-half of
the mills of the United States. This does not, however, affect the truth of
the statement that the greater part of the flour now made in this country
is made on an entirely different and vastly-improved system, which has come
to be known to the trade as the new process.
"In looking for a reason for the sudden activity and spirit of progress
which had its culmination in the new process, the character of the
wheat raised in the different sections of the Union must be taken into
consideration. Wheat may be divided into two classes, spring and winter,
the latter generally being more starchy and easily pulverized, and at the
same time having a very tough bran or husk, which does not readily crumble
or cut to pieces in the process of grinding. It was with this wheat that
the mills of the country had chiefly to do, and the defects of the old
system of milling were not then so apparent. With the settlement of
Minnesota, and the development of its capacities as a wheat-growing State,
a new factor in the milling problem was introduced, which for a time bid
fair to ruin every miller who undertook to solve it. The wheat raised in
this State was, from the climatic conditions, a spring wheat, hard in
structure and having a thin, tender, and friable bran. In milling this
wheat, if an attempt was made to grind it as fine as was then customary to
grind winter wheat, the bran was ground almost as fine as the flour, and
passed as readily through the meshes of the bolting reels or sieves,
rendering the flour dark, specky, and altogether unfit to enter the Eastern
markets in competition with flour from the winter wheat sections. On the
other hand, if the grinding was not so fine as to break up the bran,
the interior of the berry being harder to pulverize, was not rendered
sufficiently fine, and there remained after the flour was bolted out a
large percentage of shorts or middlings, which, while containing the
strongest and best flour in the berry, were so full of dirt and impurities
as to render them unfit for any further grinding except for the very lowest
grade of flour, technically known as 'red dog.' The flour produced from
the first grinding was also more or less specky and discolored, and, in
everything but strength, inferior to that made from winter wheat, while the
'yield' was so small, or, in other words, the amount of wheat which it took
to make a barrel of flour was so large, that milling in Minnesota and other
spring wheat sections was anything but profitable.
"The problem which ten years since confronted the millers of this city was
how to obtain from the wheat which they had to grind a white, clear flour,
and to so increase the yield as to leave some margin for profit. The first
step in the solution of this problem was the invention by E. N. La Croix
of the machine which has since been called the purifier, which removed the
dirt and light impurities from the refuse middlings in the same manner that
dust and chaff are removed from wheat by a fanning mill. The middlings thus
purified were then reground, and the result was a much whiter and cleaner
flour than it had been possible to obtain under the old process of low
close grinding. This flour was called 'patent' or 'fancy,' and at once took
a high position in the market. The first machine built by La Croix was
immediately improved by George T. Smith, and has since then been the
subject of numberless variations, changes, and improvements; and over the
principles embodied in its construction there has been fought one of the
longest and most bitter battles recorded in the annals of patent litigation
in this country. The purifier is to-day the most important machine in use
in the manufacture of flour in this country, and may with propriety be
called the corner-stone of new process milling. The earliest experiments in
its use in this country were made in what was then known as the 'big mill'
in this city, owned by Washburn, Stephens & Co., and now known as the
Washburn Mill B.
"The next step in the development of the new process, also originating
in Minneapolis, was the abandonment of the old system of cracking the
millstone, and substituting in its stead the use of smooth surfaces on the
millstones, thus in a large measure doing away with the abrasion of the
bran, and raising the quality of the flour produced at the first grinding.
So far as we know, Mr. E. R. Stephens, a Minneapolis miller, then employed
in the mill owned by Messrs. Pillsbury, Crocker & Fish, and now a member of
the prominent milling firm of Freeman & Stephens, River Falls, Wisconsin,
was the first to venture on this innovation. He also first practiced the
widening of the furrows in the millstones and increasing their number, thus
adding largely to the amount of middlings made at the first grinding, and
raising the percentage of patent flour. He was warmly supported by Amasa K.
Ostrander, since deceased, the founder and for a number of years the editor
of the _North-Western Miller_, a trade newspaper. The new ideas were for a
time vigorously combated by the millers, but their worth was so plain that
they were soon adopted, not only in Minneapolis, but by progressive millers
throughout the country. The truth was the 'new process' in its entirety,
which may be summarized in four steps--first, grinding or, more properly,
granulating the berry; second, bolting or separating the 'chop' or meal
into first flour, middlings, and bran; third, purifying the middlings,
fourth, regrinding and rebolting the middlings to produce the higher grade,
or 'patent' flour. This higher grade flour drove the best winter wheat
flours out of the Eastern markets, and placed milling in Minnesota upon a
firm basis. The development of the 'new process' cannot be claimed by any
one man. Hundreds of millers all over the country have contributed to its
advance, but the millers of Minneapolis have always taken the lead.
"Within the past two or three years what may be distinctively called the
'new process' has, in the mills of Minneapolis and some few other leading
mills in the country, been giving place to a new system, or rather, a
refinement of the processes above described. This latest system is known to
the trade as the 'gradual reduction' or high-grinding system, as the 'new
process' is the medium high-grinding system, and the old way is the low or
close grinding system. In using the gradual reduction in making flour the
millstones are abandoned, except for finishing some of the inferior grades
of flour, and the work is done by means of grooved and plain rollers, made
of chilled iron or porcelain. In some cases disks of chilled iron, suitably
furrowed, are used, and in others concave mills, consisting of a cylinder
running against a concave plate. In Minneapolis the chilled iron rolls take
the precedence of all other means.
"The system of gradual reduction is much more complicated than either of
those which preceded it; but the results obtained are a marked advance over
the 'new process.' The percentage of high-grade flour is increased, several
grades of different degrees of excellence being produced, and the yield
is also greater from a given quantity of wheat. The system consists in
reducing the wheat to flour, not at one operation, as in the old system,
nor in two grindings, as in the 'new process,' but in several successive
reductions, four, five, or six, as the case may be. The wheat is first
passed through a pair of corrugated chilled iron rollers, which merely
split it open along the crease of the berry, liberating the dirt which lies
in the crease so that it can be removed by bolting. A very small percentage
of low-grade flour is also made in this reduction. After passing through
what is technically called a 'scalping reel' to remove the dirt and flour,
the broken wheat is passed through a second set of corrugated rollers, by
which it is further broken up, and then passes through a second separating
reel, which removes the flour and middlings. This operation is repeated
successively until the flour portion of the berry is entirely removed from
the bran, the necessary separation being made after each reduction. The
middlings from the several reductions are passed through the purifiers,
and, after being purified, are reduced to flour by successive reductions
on smooth iron or porcelain rollers. In some cases, as stated above, iron
disks and concave mills are substituted for the roller mill, but the
operation is substantially the same. One of the principal objects sought to
be attained by this high-grinding system is to avoid all abrasion of the
bran, another is to take out the dirt in the crease of the berry at the
beginning of the process, and still another to thoroughly free the bran
from flour, so as to obtain as large a yield as possible. Incidental to the
improved methods of milling, as now practiced in this country, is a marked
improvement in the cleaning of the grain and preparing it for flouring. The
earliest grain-cleaning machine was the 'smutter,' the office of which was
to break the smut balls, and scour the outside of the bran to remove any
adhering dust, the scouring machine being too harsh in its action, breaking
the kernels of wheat, and so scratching and weakening the bran that it
broke up readily in the grinding. The scouring process was therefore
lessened, and was followed by brush machines, which brushed the dirt,
loosened up and left by the scourer, from the berry. Other machines for
removing the fuzzy and germ ends of the berry have also been introduced,
and everything possible is done to free the grain from extraneous
impurities before the process of reduction is commenced. In all the minor
details of the mill there has been the same marked change, until the modern
merchant mill of to-day no more resembles that of twenty-five years ago
than does the modern cotton mill the old-fashioned distaff. The change has
extended into the winter wheat sections, and no mill in the United States
can hope to hold its place in the markets unless it is provided with the
many improvements in machinery and processes which have resulted from the
experiments begun in this city only ten years since, and which have
made the name of Minneapolis and the products of her many mills famous
throughout the world. The relative merits of the flour made by the new
process and the old have been warmly discussed, but the general verdict
of the great body of consumers is that the patent or new process flour is
better in every way for bread making purposes, being clearer, whiter, more
evenly granulated, and possessing more strength. Careful chemical analysis
has confirmed this. As between winter and spring wheat flours made by the
new process and gradual reduction systems, it maybe remarked that the
former contain more starch and are whiter in color, while the latter,
having more gluten, excel in strength. In milling all varieties of wheat,
whether winter or spring, the new processes are in every way superior to
the old, and, in aiding their inception and development, the millers of
Minneapolis have conferred a lasting benefit on the country.
"Minneapolis, Minn., December 1, 1880."