SIRUP.
A very common form in which sugar is used in this country is in the form of sirup. The United States more than any other nation consumes viscous liquid solutions of sugar as a condimental food product, especially at breakfast on hot cakes and other articles of diet. Table sirup is an almost uniform article of diet upon the American breakfast table whether in the household, the hotel, or restaurant.
Maple Sirup.
—Among the sirups, first of all must be mentioned the most valuable and highly appreciated, namely, maple sirup. Maple sirup is the product of the evaporation of the juice of the sap of the maple tree to a consistency in which only about 25 or 30 percent of its weight is water. This is sufficient to prevent the crystallization of the sugar for at least a reasonable length of time. Maple sirup is best when freshly made, and if kept through the summer should be put in tins and tightly sealed while hot. In this condition it will keep its original flavor almost entirely, whereas if left in barrels or other ordinary receptacles its flavor is impaired. Maple sirup is also made by dissolving maple sugar as occasion may require, but this kind is not so highly prized as that made directly from the maple sap.
Fig. 80.—Small Primitive Mill for Extracting Juice From Sugar Cane for Sirup Making.—(Photograph by H. W. Wiley.)
Analysis of Maple Sirup.
—The average composition of ten samples of maple sirup of known purity is as follows:
| Total solids, | 70.50 | percent |
| Water, | 31.40 | „ |
| Ash, | .53 | „ |
| Sucrose, | 64.10 | „ |
| Reducing sugar, | 1.30 | „ |
The study of the ash of maple sirup is an important point in connection with its purity. It is distinctly different from the ash of the sugar cane and sorghum, and its study should not be neglected in all cases where there is any doubt respecting the genuineness of the samples.
Fig. 81.—Mill and Evaporating Apparatus for Sirup Making in Georgia.—(Bulletin 70, Bureau of Chemistry.)
Fig. 82.—Relative Length of Canes Used for Sirup Making.—(Photograph by H. W. Wiley.)
Cane Sirup.
—Sugar cane sirup is made by expressing the juice of the sugar cane as described, clarifying, and evaporating the juice to a consistency where only about 25 or 30 percent of the water remains, which is sufficient to prevent the sugar from crystallizing for a reasonable length of time. Sugar cane sirup is made in hundreds of small factories in the states of Texas, Louisiana, Alabama, Mississippi, Georgia, South Carolina, and Florida. It is usually made in a small way with mills driven by a horse or mule and with primitive methods of evaporation in an ordinary kettle. Hard pine wood is burned for the evaporation and the empyreumatic flavor of the pine is often absorbed by the sirup. In [Figs. 80] and [81] are shown typical apparatus used for the manufacture of sirup from sugar cane in Georgia and in [Fig. 82] the relative length of canes ready for manufacture. In factories where modern apparatus is used, in so far as I know, the vacuum process is not employed. In fact, except for economy of fuel, the vacuum process would be objectionable, since by boiling in an ordinary open kettle a larger quantity of sugar is inverted and thus the tendency to crystallization is diminished. It is a common but reprehensible practice in making sugar cane sirup to subject the freshly expressed juice to the fumes of burning sulfur. This makes a light-colored sirup but introduces a substance highly objectionable and one which destroys to a certain degree the flavor of the product. Experiments made by the Department of Agriculture show that delicious, wholesome, and palatable sugar cane sirup is best made by clarifying the expressed juice solely by means of heat and mechanical separation of the coagulum. The addition of lime or any other clarifying reagent is unnecessary and only makes a sirup of less desirable and less palatable quality. Since cane sirup is made uniformly in open kettles or pans there is a slight caramellization of the sirup during evaporation which gives a reddish tint to the product, which should be a mark of superiority instead of being so often regarded as a mark of inferiority. The consumer should always be suspicious of a sugar cane sirup which is light in color. It is probably a case of “Greeks bearing gifts” in the form of sulfurous acid or other injurious bleaching materials. Sugar cane sirup is not appreciated by the people of the North. In fact it is rarely seen or consumed by them. In its own country, however, it is a staple article of diet, highly esteemed, wholesome, palatable, and nutritious.
Analysis of Sugar Cane Sirup.
—The average composition of thirteen samples of cane sirup of known purity is as follows:
| Total solids, | 75.0 | percent |
| Water, | 25.8 | „ |
| Ash, | 1.2 | „ |
| Sucrose, | 52.0 | „ |
| Reducing sugar, | 17.6 | „ |
Sorghum Sirup.
—The sorghum plant (Sorghum saccharatum) is grown practically in every state in the Union, but principally in Kansas. Some of the very best sorghum sirup made in the United States, however, is made in Minnesota, and this plant can be used for sirup making purposes over the whole area of the United States.
The method of manufacture is exactly that of sugar cane sirup. It is made in small mills mostly driven by horse power, though some large factories have steam apparatus for its manufacture. It should also be made without the use of any other clarifying reagent than heat. Sorghum sirup has a peculiar flavor which is not disagreeable to those accustomed to its use. It is extremely wholesome, highly nutritious, and palatable. It is a staple article of diet with thousands of families in the United States, principally in the northern and central portion. It rarely is made in the New England states and not very often in those southern states where sugar cane can be used in its place, since the sugar cane makes a sirup which is preferred by most people.
Analysis of Sorghum Sirup.
—The average composition of ten samples of sorghum sirup of known purity is as follows:
| Total solids, | 76.0 | percent |
| Water, | 28.6 | „ |
| Ash, | 4.0 | „ |
| Sucrose, | 36.7 | „ |
| Reducing sugar, | 26.6 | „ |
Molasses.
—The term “molasses” is properly applied to the saccharine product which is separated from sugar in the process of manufacture. It is well to clearly discriminate in the use of the term in order that no confusion or misunderstanding may arise. To this end the terms “sirup” and “molasses” may be contrasted. A sirup is the direct product of the evaporation of the juice of a sugar-yielding plant or tree without the removal of any of the sugar. The term molasses applies to the same process with the exception of the fact that sugar has been removed at least partially by crystallization and some kind of mechanical separation of the crystals from the remaining liquid. Molasses, therefore, to use a term employed in chemistry, may be considered the “mother liquid” which has produced the crystallization of the sugar. The production of molasses has already been sufficiently described in the article on sugar making. The molasses is either separated by gravitation as in the old style of drying sugar or, as at the present time, almost exclusively by centrifugal action. The molasses naturally contains all the substances in solution or suspension which are not retained upon the gauze of the centrifugal. It differs from the total mass of evaporated sugar liquid only in the fact that a large portion of the sucrose or crystallizible sugar has been separated. The sugar juices of the cane and sorghum contain considerable quantities of sugar of a kind different from sucrose or common sugar, namely, an invert sugar, a “reducing sugar,” as it is called, which consists usually of about equal parts of dextrose and levulose. During the process of manufacture small portions of the sucrose are converted into sugar of this kind thus increasing its quantity. In the final crystallization there is always a portion of sugar uncrystallized remaining as a viscous liquid in contact with the crystallized particles. This natural invert sugar which is in the juice, the small portion formed from the sucrose during the process of manufacture, and the part of sucrose remaining uncrystallized in the mother liquid constitutes the molasses. In the washing of sugar the water which is used also passes into the molasses thus diluting it somewhat from its natural consistence. In the sugar refinery the molasses is made up of practically such materials as just mentioned, but inasmuch as the separation of the sugar is more complete the other portions of the molasses, namely, the mineral salts, particularly appear in a very much larger proportion than in the ordinary molasses as will be seen by the analysis of these bodies.
Varieties of Molasses.—New Orleans Molasses.
—The real New Orleans molasses is the product of the manufacture of sugar in the old-fashioned way in the open kettle and without the aid of vacuum pans. In this process the crystallization of the sugar does not take place during the boiling but the concentrated liquid is placed in tanks where the crystallization takes place. When this is complete it is broken up into small fragments and placed in a hogshead standing in an upright position, the bottom of which is perforated and covered with straw or fragments of sugar cane. When the hogshead is filled with the crystallized mixture, through the action of gravity the liquid portion gradually sinks and passes out at the bottom of the hogshead. This natural separation of the molasses makes a product of exquisite palatability and one of a character which it is difficult to equal even by the production of high-grade sirup. Before the Civil War this kind of molasses was used throughout the United States. At the present time only extremely small quantities of it are made inasmuch as the open kettle process is practically a lost industry in the South. The term “New Orleans molasses” as used at the present day, therefore, applies to a product of quite a different character.
Sugar Cane Molasses.
—Since the introduction of modern processes of making sugar, namely the vacuum pan and centrifugal process, the character of molasses from the sugar cane factory has constantly deteriorated. This is a natural deterioration due to the improvement in the method of sugar making. Much larger quantities of sugar are now obtained in a crystallized state than formerly. The molasses is to this extent impoverished and the impurities contained therein increased proportionately. It is quite common now in the process of manufacture of sugar from sugar cane to secure at least three crystallizations.
First Molasses.
—When the sugar is crystallized in the vacuum pans and separated from the molasses in the centrifugal the product which is obtained is called “first molasses.” Usually this molasses is diluted to a sirup and reboiled in connection with the clarified juices direct from the sugar cane and thus a second portion of sugar is obtained or the molasses may be boiled separately and a second crystallization of the sugar separated by the centrifugal. The molasses from this product is called “second molasses” and is inferior in quality to the first molasses.
Third Molasses.
—The second molasses is reboiled to a thick consistency and placed in wagons, transferred to a warm room where it is allowed to remain, sometimes for two or three months, when a third crystallization takes place. The sugar from this crystallization is separated as usual by the centrifugal, and a third molasses produced of still greater inferiority. Thus, in the best sugar factories high-grade molasses is not made in the United States but only that of inferior quality. This molasses is largely used for fermentation, or is fed to the mules on the plantations. It is also employed to a certain extent for mixing purposes as indicated above.
Analysis of First, Second, and Third Molasses.—
| Total Solids. | Sucrose. | Dextrose. | Levulose. | Ash. | Albumi- noids. | Amids. | Acids and Gums. | |
|---|---|---|---|---|---|---|---|---|
| Percent. | Percent. | Percent. | Percent. | Percent. | Percent. | Percent. | Percent. | |
| First, | 80.00 | 53.60 | 8.76 | 8.00 | 4.00 | 0.20 | 0.94 | 4.50 |
| Second, | 80.00 | 41.70 | 12.20 | 12.50 | 5.35 | 0.25 | 1.50 | 6.50 |
| Third | 80.00 | 31.70 | 15.00 | 16.50 | 6.30 | 0.30 | 2.00 | 8.20 |
The increasing content of dextrose and levulose, of ash, acids, and gums, and the decreasing content of sucrose or pure sugar are characteristic of the second and third molasses.
The above analyses show the progressive change in molasses due to the separation of the successive portions of sugar and indicate the lowering of the quality of the molasses, at least for food purposes, as the separation of the sugar becomes more complete. It is evident that in the manufacture of sugar in this way, in which very probably an effort is made to get the highest possible yield, the resulting final molasses is a substance quite unfit for human consumption.
Sugar-house Molasses.
—Attention has already been called to the production of sugar-house molasses or sugar refinery molasses. This is a product which in its physical appearance is far superior to the third molasses of the sugar factory and this superiority is due to the fact that all suspended matter in the refined molasses has been separated by filtration. In so far as soluble materials which are not food is concerned, however, the refinery molasses contains even larger proportions than the sugar factory molasses. The refinery molasses is not usually considered suitable for food except when diluted as has been before indicated in the way of mixing sirup.
Mixed Sirups.
—By far the greater part of the sirups used in the United States are mixtures of two or more saccharine substances. The glucose of commerce is the base and perhaps chief constituent of the most of these mixtures. The glucose, being colorless and of a thick body, forms an ideal base as far as physical properties are concerned, for a table sirup. The quantity used varies very largely, but in general the glucose constitutes by far the larger percentage of the mixed product. Since glucose has only a very slightly sweet taste and is devoid of the general palatable properties which make a sirup attractive, it is colored and flavored with the product of the sugar cane or the maple tree. Sorghum sirup is also used very extensively in mixing. The process of mixing is an extremely simple one. The glucose is warmed until it is easily workable and the added sirups or molasses which are used for coloring and flavoring mixed intimately with it. In large factories this is done by mechanical mixers while in a small way it may be done by hand. Instead of glucose, one sirup itself may be used as the base and mixed with another for flavor, as, for instance, in the case of mixed maple sirup. Very commonly the brown sugar is melted with water and this is used as a base for the formation of sirups. Whichever may be the case the principle of the process remains the same, namely, using as the base a cheaper and less palatable material and flavoring and coloring with the more expensive and more palatable material. From a dietetic and commercial point of view there can be no valid objection raised to this method of mixing sirups. The product is, as a rule, attractive, palatable, and wholesome.
Attention has already been called to the fact that the final molasses in the sugar refinery, after all the sugar has been extracted that can possibly be gotten out by the most approved modern process, is used very extensively for mixing purposes. This molasses has a very high content of soluble salts, reaching often 8 percent or more, which gives a distinct flavor and character. It also has acquired a certain flavor from repeated filtering over bone-black and in general has a strong and pronounced flavor which gives it a peculiar value as a flavoring agent. It is also a clear product, free from suspended matter by reason of its repeated filtration. It can thus be mixed with glucose and forms a bright mixture, devoid of suspended matter and turbidity, and is attractive to the eye. Ten percent of molasses of this kind added to a glucose will make a mixture which is attractive and salable, and, it may also be added, palatable. The other products which are used for mixing with the glucose in the manufacture of table sirup consist of the molasses obtained from cane sugar factories or the sirups made directly from the sugar cane and sorghum. All these bodies have valuable mixing properties and small quantities of them give sufficient color and flavor to the mixed product.
Adulteration of Mixed Sirups.
—The adulteration of mixed sirups consists chiefly of adulterations that are in the materials from which they are made. Glucose itself often contains sulfurous acid used for bleaching in the process of manufacture. It also contains considerable quantities of sulfate or chlorid of lime incident to its manufacture and coming from the sulfuric or hydrochloric acid used in the hydrolysis of the starch from which it is made. The molasses which is used for coloring and flavoring may also contain injurious substances. For instance, sulfurous acid is very extensively used in the manufacture of cane sugar and this acid becomes concentrated in the molasses. Lime is used very extensively in the clarification of the juices and this lime is not wholly separated but some of it is concentrated in the molasses. A moderate amount of lime, however, is not objectionable. Salts of tin are frequently employed in washing the sugar in a centrifugal and these salts are found concentrated in the molasses. The excess of bluing which is used in the centrifugal is also found in the molasses. Various forms of acid phosphates are frequently employed in the clarifying of the cane juices and a part of these is also found concentrated in the molasses. In fact the molasses from sugar cane factories very frequently contains such quantities of these added substances as to render it unfit for human consumption. It is true that these substances are diluted when mixed with glucose, but this is not a sufficient excuse to warrant their employment. It is possible to obtain unobjectionable sirups and molasses for mixing purposes and manufacturers should be held strictly to account if this is not done. In so far as has come to my knowledge there are no adulterants directly added to the mixed sirups except for bleaching purposes.
Attention should be called, however, to still another form of adulteration due to the fact that the molasses from the sugar cane factories is often so dark-colored as to be even unfit for mixing.
In such cases it is not uncommon to bleach the molasses by adding zinc and acid producing nascent hydrogen and leaving the salts of zinc, either the sulfite or chlorid as the case may be, in the product. Molasses containing salts of any of these heavy metals, namely, zinc, tin, or lead, should be rigidly excluded from consumption.
General Observations.
—If a sirup is to be considered in the light of the definitions already given, as the result of evaporation, after proper clarification of the saccharine juices of sugar-producing plants it is doubtful if the term should be used in connection with the mixed products which have been described. I have used it because these are the commercial designations. Since molasses is also used very extensively in the manufacture of these mixed sirups it might be asked if they could not also be as properly called molasses as sirup. In England the material which is called molasses in this country is usually known as treacle and the very dark molasses coming from the refinery or the sugar factory is known in both countries as “black strap.” If molasses be concentrated to a high degree and pulled while cooling the product is known as taffy in this country or toffy in England,—it is also known as molasses candy.
The general conclusion in regard to this matter is that since the processes of sugar making have been so improved as to extract the greater part of the crystallizible sugar, thus concentrating the residue of an inedible character in the molasses and since, further, the use of various chemicals in the clarifying of sugar juices has become general, all of which are practically concentrated in the molasses, this latter product has practically ceased to be edible.
The laws relating to the distillation of alcohol have been so amended as to permit the production of industrial alcohol, under conditions prescribed by the Commissioner of Internal Revenue, free of tax. Molasses is an excellent material for this purpose and, in addition to this, is the cheapest material which can be used. The obvious inference is that this material should be used exclusively for the production of industrial alcohol or for some other technical uses and no longer be prepared for human food. The production of straight, pure sirups from maple sap and the sap of the sugar cane and of sorghum and, in certain conditions, from sugar, can be easily secured in quantities sufficient to supply the demand not only for the consumption of pure sirups but also for supplying the materials which when mixed with pure glucose produce the mixed sirups of commerce. Thus inedible molasses would be eliminated from human food and mixed sirups be rendered unobjectionable articles of diet.