78 



AGRICULTURE HANDBOOK 134, U.S. DEPT. OF AGRICULTURE 



measuring standard-density sirup. The accu- 

 racy of this instrument depends on the relation 

 of Uneal expansion of the thermometer Hquid to 

 Hneal displacement of the hydrometer stem by 

 standard-density sirup at different tempera- 

 tures. When used, sufficient time must be al- 

 lowed for the thermometer of the hydrotherm 

 to warm or cool to the temperature of the sirup, 

 usually about 30 to 40 seconds. 



Since the hydrotherm is not calibrated, the 

 scale does not indicate how much too dense or 

 too thin the sirup is. 



Suinmarv 



(1) Finished sirup must contain not less than 

 66.0 percent of solids (66.0" Brix) at a tem- 

 perature of 68° F. 



(2) Table sirup that is between 66° and 67° Brix 

 has the best taste. Table sirup that is below 

 standard density tastes thin. 



(3) Use precision instruments to measure 

 standard-density sirup. 



(4) The boiling temperature of standard-den- 

 sity sirup is T F. above the temperature of 

 boiling water. 



(.5) Use a thermometer calibrated in V4° F. to 

 measure the temperature of boiling sirup. 



(6) Calibrate the thermometer frequently with 

 reference to the boiling point of water. 



(7) Completely immerse in the boiling water or 

 sap the bulb of the stem of a liquid ther- 

 mometer or that part of the stem of a dial 

 thermometer containing the bimetallic ele- 

 ment. 



(8) To test hot sirup with a hydrometer, the 

 temperature of the sirup must be noted and 

 necessary temperature corrections applied 

 to the observed hydrometer readings. Hot 

 sirup (210° to 218' F.) of standard density is 

 59. y to 59.6° Brix. 



(9) To test hot sirup with a hydrotherm, suffi- 

 cient time must be allowed for the hydro- 

 therm to come to the same temperature as 

 the sirup in which it is floated. 



STANDARD 



DENSITY 



SIRUP 



THERMOMETER 



Chart 17. — Hydrotherm for measuring density of sirup. It 

 automatically compensates for temperature correction. 



(;L\RIFK:ATlo^ ok SIRl I' 



Snjjar Sainl 



SirQp as it is drawn from the evaporator 

 contains suspended solids, commonly known as 



sugar sand. They are primarily the calcium and 

 magnesium salts of malic acid. These salts are 

 precipitated because they become less soluble 



