MAPLE SIRUP PRODUCERS MANUAL 



85 



convenient to calculate the Baume value from 

 specific-gravity tables. Thus, " Baume = sp. g. 

 (sp. g.) 



(M) 



, where M = the modulus. 



In the past, unfortunately, neither the tem- 

 perature for which the Baume scale was cali- 

 brated nor M was standardized. Today, M is 

 standardized at 145. The temperature for cali- 

 bration is standardized at 68° F. (except in Ver- 

 mont). In Vermont, the scale is marked at 36° 

 (for use at 60° F.), and standard-density sirup 

 has a Baume reading of 36° when measured at 

 60° F. In other States and for Federal sjjecifica- 

 tions, the scale is marked at 35.6° (for use at 

 68° F.). When this scale is used, standard-den- 

 sity sirup has a Baume reading of 35.6° at 68°. 

 When a Baume hydrometer is used, caution 

 must be exercised in observing the temperature 

 at which the scale is to be used. 



Aleasiirinff Doiisitv 



Measuring the density of sirup by hydrome- 

 try is relatively simple. Many people, however, 

 incorrectly assume that the observed hydrome- 

 ter reading is the true density of the sirup. This 

 error occurs because they neglect to consider 

 that sirup and sap are water solutions and 

 therefore behave as water does, expanding and 

 contracting with changes in temperature. 



Most hydrometers and re fracto meters made 

 for use in this country are calibrated for use at 

 68° F. When used to measure sirup at this 

 temperature, the observed hydrometer or re- 

 fractometer value of the sirup is the true value. 

 If sirup is heated above 68° F., it will expand to 

 a greater volume and its apparent (observed) 

 density will be less than its true density. Like- 

 wise, if sirup is chilled below 68°, it will contract 

 to a smaller volume and its apparent (observed) 

 density will be gi-eater than its true density and 

 corrections must be made. 



To make exact density measurements, sensi- 

 tive hydrometers that can be read with high 

 precision must be used. The diameter of the 

 hydrometer stem, therefore, must be small 

 enough so that a change in the density of the 

 sap or sirup equivalent to 0.1° Brix will cause 

 an observable change in the depth at which the 

 hydrometer stem floats, as measured at the 

 intersection of the liquid surface and the hy- 



drometer stem. The hydrometer will have a 

 scale with 0.1° Brix graduations and will usu- 

 ally cover a range of 10° to 12° Brix. The stem 

 will be approximately 6V2 inches long, and the 

 overall length of the hydrometer will be about 

 13 inches. This type of hydrometer will require 

 a hydrometer cup at least 13 inches deep. 



Since the Brix scale gives the density of sap 

 or sirup directly in terms of dissolved solids as 

 percentage of sugar, it is ideally suited for use 

 by the maple industry. However, as stated ear- 

 lier, many sirup hydrometers in use today have 

 Baume scales. Baume values (commonly called 

 points) can be converted to Brix values, as 

 follows: 



Brix 



Baume 



Bri,\ 



Baume 



Brix 



0.0 0.0 



0.1 .1 



0.2 .1 



0.3 .2 



0.4 .2 



0.5 ..3 



0.6 .3 



0.7 .4 



0.8 .5 



0.9 .5 



1.0 .6 



1.1 .6 



1.2 .7 



1.3 .7 



1.4 .8 



1.5 .8 



1.6 .9 



1.7 1.0 



1.8 1.0 



1.9 1.1 



2.0 1.1 



2.1 1.2 



2.2 1.2 



2.3 1.3 



2.4 1.3 



2.5 1.4 



2.6 1.5 



2.7 1.5 



2.8 1.6 



2.9 1.6 



3.0 1.7 



3.1 1.7 



3.2 1.8 



3.3 1.9 



3.4 1.9 



3.5 2.0 



3.6 2.0 



3.7 2.1 



3.8 2.1 



3.9 2.2 



4.0 2.2 



4.1 2.3 



4.2 2.4 



4.3 2.4 



4.4 2.5 



4.5 2.5 



4.6 2.6 



4.7 2.6 



4.8 2.7 



4.9 2.7 



5.0 2.8 



5.1 2.9 



5.2 2.9 



5.3 3.0 



5.4 3.0 



5.5 3.1 



5.6 3.1 



5.7 3.2 



5.8 3.2 



5.9 .3.3 



6.0 3.4 



6.5 3.6 



7.0 3.9 



7.5 4.2 



8.0 4.5 



8.5 4.7 



9.0 5.0 



9.5 5.3 



10.0 5.6 



10.5 5.9 



11.0 6.1 



11.5 6.4 



12.0 6.7 



12.5 7.0 



13.0 7.2 



Baume 



13.5 7.5 



14.0 7.8 



14.5 8.1 



15.0 8.3 



15.5 8.6 



16.0 8.9 



16.5 9.2 



17.0 9.5 



17.5 9.7 



18.0 10.0 



18.5 10.3 



19.0 10.6 



19.5 10.8 



20.0 11.1 



20.5 11.4 



21.0 11.7 



21.5 11.9 



22.0 12.2 



22.5 12.5 



23.0 12.7 



23.5 13.0 



24.0 13.3 



24.5 13.6 



25.0 13.8 



25.5 14.1 



26.0 14.4 



26.5 14.7 



27.0 14.9 



27.5 15.2 



28.0 15.5 



28.5 15.8 



29.0 16.0 



29.5 16.3 



30.0 16.6 



30.5 16.8 



31.0 17.1 



31.5 17.4 



