Understanding sugar cooking is important in the preparation of desserts and confections because sugar syrups of various strengths are often required (see, for example, Italian Meringue ).
The Brix and Baumé Scales
The Brix scale is a measure of the sugar concentration in a solution. It is named after Dr. Brix , who refined the earlier Balling scale to make it more accurate. Each degree (1°) of Brix is equal to a 1% concentration of sugar in solution when measured at 20°C (68°F). For example, a 15% sugar solution (15 grams of sugar in 100 grams of syrup; thus, a syrup consisting of 15 grams of sugar and 85 grams of water) would measure 15° Brix.
A simple way to measure sugar concentration is to use a hydrometer , a hollow glass tube with a weight at one end and a scale marked inside the length of the tube. (A hydrometer specifically intended to measure sugar concentration is also called a saccharometer .) The hydrometer is placed in the liquid at the correct temperature and the sugar concentration is read off the scale at the surface of the water. The higher the concentration of sugar, the higher the tube floats. This instrument is accurate enough for most purposes in the bakeshop.
A more scientific way to measure Brix is to use a refractometer, which measures the angle at which the solution bends a ray of light.
A second index used to indicate syrup density is the Baumé (boh may) scale, named after Antoine Baumé. Strictly speaking, the Baumé scale measures not the sugar concentration but the specific gravity , which is the ratio of the weight of the liquid compared to the weight of the same volume of water. Nevertheless, the measure is close enough to enable it to be used for sugar solutions. Each degree Baumé is equal to about 1.8% sugar concentration, although this varies slightly along the length of the scale. For example, 30° Brix equals 16.6° Baumé; 70° Brix equals 37.6° Baumé.
In this book, we make use of these sugar density scales in our discussion of frozen desserts. This is an important measurement because sugar concentration affects the freezing point of liquids.
