LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF CHEMISTRY, Washington, D. C., May 25, 1910. SIR: I have the honor to transmit for your approval a report on the manufacture and analysis of maple-sap sirup prepared in the Sugar Laboratory of this Bureau after an extensive investigation. Though considerable work has been done along this line by individuals on a comparatively small number of samples representing restricted areas, no systematic study covering such a wide field as in the present case previously has been made. The analyses given represent 481 samples of maple sirups of known purity from the most important mapleproducing States of this country and from Canada; they form, therefore, a basis for the comparison and grading of maple sirups. The studies of the effect of environment on the composition of this product constitute another contribution to the general investigations on the effect of environment on composition, especially of sugar-producing plants, which have been prosecuted in this Bureau since 1887. The bulk of the analytical work reported was performed by C. G. Church and S. F. Sherwood of the Sugar Laboratory. Acknowledgment is also made of the valuable suggestions offered by Mr. C. H. Jones of Vermont and Mr. J. H. Grimm of Canada, especially in regard to the production of maple sirup in their respective localities. I recommend that this report be published as Bulletin 134 of the Bureau of Chemistry. Respectfully, Hon. JAMES WILSON, Secretary of Agriculture. H. W. WILEY, Chief. 3 Tabulation of descriptive data and results of examination. Discussion of manufacturing data... 18 18 19 50 Factors influencing the character of the final product.. Comparison of sirups from covered and uncovered sap buckets.. Canadian sirup as compared with United States sirup. Statistics of the maple sirup industry of the United States. ILLUSTRATIONS. PLATE. Page. 93 93 95 96 97 98 98 100 102 104 PLATE I. Standard colors by which the sirups were graded TEXT FIGURES. FIG. 1. Apparatus for preparation of standard caramel. 2. Examples of covered buckets...... Page. 58 15 50 3. Open buckets and too many of them.. 51 4. Collecting tank......... 52 5. Map showing effect of latitude on ash content, lead number, and malicacid value of maple sirups.... 101 MAPLE-SAP SIRUP. INTRODUCTION. ORIGIN AND NATURE OF MAPLE SIRUP. The manufacture of maple sirup probably dates back to a period before the advent of the white man in this country. Henshaw," Chamberlain, and Sy have reviewed many of the writings of the early discoverers in which allusions are made to the preparation by the Indians of a kind of sugar and sirup from the sap of the maple tree. There is no agreement, however, as to who discovered the fact that this tree possesses a sweet sap. Some claim that the French taught the Indians how to make the sirup and sugar, and others that the Indians taught the white people, the latter theory appearing to be the more probable one. The sirup manufactured from the sap of the maple tree has become a staple article concerning whose character and constitution there is considerable discussion. Obviously the sap of a living maple tree, boiled down to the proper consistency (see pages 8 and 60), without the addition of any foreign substance other than the usual cleansing materials, is a maple sirup. However, a maple sirup may also be made by dissolving in water the solid or semisolid product resulting from boiling the sap down to the point of crystallization, with or without the use of cleansing agents. The latter is a maple-sugar sirup while the former is a maple-sap sirup— both are maple sirups. It is wrong to style a sirup made by dissolving maple sugar a maple-sap sirup. True, it has come originally from the maple sap, but by evaporating further, making sugar and then dissolving it in water, the taste and color have been changed somewhat and it becomes a maple-sugar sirup. Buyers classify sirup as "sap" sirup and "sugar" sirup, and claim that by taste and consistency they are able to distinguish one from the other. The sap of the tree is obtained by tapping it; chopping down the tree and then extracting the dead wood with water does not yield a sap, nor does an extract prepared from maple wood, cut and cured under ordinary conditions, contain any appreciable amounts a Amer. Anthropologist, 1890, 3: 341. b Ibid., 1891, 4: 39. CJ. Frank. Inst., October, 1908. |