84 



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



PN-4796 



Figure 99. — A hydrometer is a simple, inexpensive instru- 

 ment for precisely measuring the density (" Brix) of the 

 sirup. The hydrometer should be read at eye level. The 

 temperature of the sirup must be measured and a 

 temperature correction made. 



A good approximation of the weight of sugar 

 in any lot of maple sirup, whether or not it is 

 standard-density sirup, can be found by multi- 

 plying the weight of the sirup by its density 

 (° Brix) and dividing by 100. This information is 

 important to the producer who sells his sirup 

 wholesale, since the price is based on its solids 

 (sugar) content. Thus, 100 pounds of sirup at 65° 

 Brix contains 65 pounds of sugar, whereas 100 

 pounds of standard-density sirup (66.0° Brix) 

 contains 66.0 pounds of sugar. Therefore, 100 

 pounds of the low-density sirup has a lesser 

 value than 100 pounds of standard-density sir- 

 up. Likewise, 100 pounds of sirup with a den- 

 sity of 66.8° Brix contains 66.8 |X)unds of sugar, 

 which is more than that contained in 100 

 pounds of standard-density sirUp, and it has a 

 greater value. If sirup has an original density 

 of more than 67° Brix, the excess sugar will 

 precipitate out, and the hydrometer will not 

 measure it. 



To obtain the weight of sugar in sirup when 

 density is measured by a hydrometer whose 



VT BAUME 



(eo'F) 



25 



HYDROMETERS 



NY BAUME BRIX 

 (68°E) 



BRIX 



(ee-E) 



r~\ 



30 



35 





30 



60 

 61 

 62 



63 

 64 

 65 

 66 

 -167 

 J 68 



Chart 20. — The three hydrometer scales used in testing 

 sirup. Left, Vermont Baume scale, marked for testing 

 sirup at 60° F.; standard-density sirup at this tempera- 

 ture is indicated by the heavy line at 36°. Center, 

 hydrometer with double scale, marked for testing sirup 

 at 68°; standard-density sirup on the Baume scale of 

 this hydrometer is indicated by the hea\y line at 35.27°. 

 The double scale requires a spindle so large in diameter 

 that accurate readings are difficult to make, since the 

 scale must be compressed, ffi^/if, Brix scale, marked for 

 testing sirup at 68°; standard-density sirup at this 

 temperature is indicated by the heavy line at 65.46°. 



scale is in specific gi-avity or ° Baume requii-es 

 more involved calculation because neither scale 

 has a direct relation to the amount of sugar 

 present. 



Baume Scale 



Even though the Baume scale does not ex- 

 press directly the solids content of maple sirup 

 and its continued use cannot be recommended, 

 its long past use by the maple industry justifies 

 the following explanation and the tabulation on 

 page 85 for the conversion of Baume values 

 (points) to ° Brix. 



The Baunie scale relates the density of a 

 liquid to that of a salt solution, but it is more 



