MAPLE SIRUP PRODUCERS MANUAL 



87 



the time the reading was made is known. The 

 temperature of the sirup should be measured 

 with a pi'ecision Fahrenheit thermometer cali- 

 brated in intervals of 1.0°, or preferably 0.5°. 

 Table 14 shows the amount to be added to or 

 subtracted fi'om the observed Brix reading to 

 obtain the true density of sirup measured at a 

 temperature other than 6S' F. 



The following examples show how to obtain 

 the true density of sirup in ° Brix: 



Example 1. What is the true density, in 

 ° Brix, of sirup having an observed density of 

 65.9° Brix at 165° F.? 



Since the observed reading is below 69.9° 

 Brix, the correction to use is in column 2 of 

 table 14. Locate the temperature 165° F. in 

 column 1. Opposite this in column 2 is 5.0° Brix, 

 the correction to add to the observed reading. 

 Therefore, the true density of this sirup is 65.9° 

 + 5.0°, or 70.9° Brix. 



Example 2. What is the true density of sirup 

 having an observed density of 61.0° Brix at 

 5r F.? 



Since the observed reading is below 69.9° 

 Brix, the correction to use is in column 2 of 

 table 14. Locate the temperature closest to 

 57° F. (55° F.) in column 1. Opposite this in 

 column 2 is 0.5° Brix, the correction to subtract 

 from the observed reading. Therefore, the true 

 density of this sirup is 61.0° - 0.5°, or 60.5° Brix. 



A<lj listing; Density 



Heavy sirup decreases the potential number 

 of gallons of sirup that can be made from a 

 quantity of sap. Sirup should, therefore, be 

 adjusted to the proper density. Further, sirup 

 with a density of more than 67° Brix (more than 

 36° Baume at 68° F. or 36.2r Baume at 60° F.) 

 must be diluted or it will crystallize on storage. 

 The sirup can be diluted either by adding water 

 or sap or low-density sirup. 



The amount of water needed to adjust 100 

 pounds of heavy sirup, or any part thereof, to 

 the standard density of 66.0° Brix is shown in 

 table 15. If sap or low-density sirup is used, the 

 amount required can be calculated from the 

 densities of the two liquids by Pearson's square. 

 The calculation is explained on page 126. 



The calculation for adjusting heavy sirup can 

 be done accurately only after its true density 

 (Brix value) has been determined. 



If the true density of sirup is known, the 

 amount of water to add to yield 66'-Brix sirup 

 can be obtained directly from table 15. After 

 adding the water, stir the sirup well to insure 



Table 14. — Corrections to be applied to ob- 

 served Brix readings of maple simp to com.- 

 pensate for effects of tem.perature ' 



Correction to subtract from (-) or 

 Temperature of added to ( + ) observed Brix reading 

 sirup in hydrometer of — 



cup, ° F. 



60.0°-69.9° 



69.9° and higher 



(1) (2) (3) 



° Brix ° Brix 



32 -1.4 -1.5 



,35 -, -1.3 -1.4 



40 -1.2 -1.2 



45 -1.0 -1.0 



50 -.8 -.8 



55 -.5 -.6 



60 -.3 -.4 



65 -.1 -.1 



68- .0 ,0 



70 +.1 +.1 



75 +.3 -I-.3 



80 +.5 +.5 



85 +.8 +.8 



90 +1.0 -1-1.0 



95 -1-1.2 -1-1.2 



100 -1-1.5 -H.5 



105 -1-1.7 -1-1.7 



110 -1-1.9 -1-1.9 



115 -1-2.2 -1-2.2 



120 -1-2.4 -1-2.4 



125 -1-2.7 -1-2.7 



130 -1-3.0 4-2.9 



135 -1-3.2 -H3.2 



140 -1-3.5 -1-3.4 



145 -1-3.8 -1-3.7 



1.50 -1-4.1 -1-4.0 



155 -1-4.4 -1-4.2 



160 -1-4.7 -1-4.5 



165 -1-5.0 -1-4.9 



170 -1-5.5 -1-5.2 



176 -1-5.9 -1-5.7 



' If observed reading is in ' Baume, first convert to 

 Brix (p. 85), then apply the temperature correction. 



- Most hydrometers are calibrated at exactly this tem- 

 perature. 



