be acted on even at slightly elevated temperatures.
In one of his experiments, at a temperature no
higher than 68 deg. Fahr., a quantity of starch,
at the end of twenty-four hours, was converted
into syrup, which yielded seventy-seven per cent.
of saccharine matter.[28] It may be thought that
I have overrated the importance of this subject, but
it is believed that a careful examination of the
facts will relieve me from this charge. I
am now satisfied that, if the proportion of water
in our exported breadstuffs could be reduced to about
five or six per cent., one of the great causes
of complaint in regard to them would be completely
removed.
Kiln-drying of breadstuffs, and exclusion of air.—The injury which our breadstuffs sustain by the large proportion of water can of course be prevented only by careful drying before shipment, and by the employment of barrels rendered as impervious as possible to the influence of atmospheric moisture.
In my first report, I have spoken favorably of the process of drying by steam, according to the plan patented by Mr. J.R. Stafford. I still think this mode possesses great advantages over those previously followed, and which almost always injured the quality of the grain or flour: but from some trials which I have made during the past year, it is inferred that the exposure to the heat is perhaps usually not sufficiently prolonged to answer the purpose intended by the operation. I have often observed that samples of wheat flour, after being exposed to the heat of the salt water-bath oven (220 deg. Fahr.) for two or three hours, lost weight by a further continuance of the heat. An apparatus has been patented by Mr. J.H. Tower, of Clinton, N.Y., consisting of a cylinder of square apartments or tubes, into which the grain or flour is introduced, and subjected to heat while in rapid revolution. I examined samples which had been subjected to this operation, and ascertained that wheat flour, originally containing 14.80 per cent. of water, had the proportion reduced to 10.25 per cent., while in wheat the proportion of water was reduced from 14.75 to 8.55 per cent.
Now it is probable that by either of the above modes, and perhaps by many others, the various kinds of breadstuffs may be brought to that degree of dryness which, with ordinary care, shall protect them from subsequent injury; but in order to secure this advantage, the operation must be carefully performed, and experiments must be made to ascertain how long an exposure to heat is necessary to bring the sample to the proper degree of dryness, and to determine whether in any respect its quality is impaired. It has already been stated that absolute desiccation is not necessary, even were it attainable; but any process in order to be effective should reduce the proportion of water to about six, or at most seven per cent.
I have heretofore adverted
to the great care employed in the drying
of grain in various foreign
countries, and to which the preservation
of it for a great number of
years is to be ascribed.


