The solubility of the sugars determines their use to a certain extent. It is obvious to one who does a great deal of cooking that a sugar that requires 6 pounds of water to dissolve 1 pound of sugar, could not be used for concentrated sugar products like jellies, jams, frostings, or even cakes.

Sucrose. Sucrose has the greatest solubility of the disaccharid sugars. Browne in his "Handbook of Sugar Analysis" states that, at 20°C, 204 grams are soluble in 100 cc. of water. Thus at room temperature about 2 grams of sucrose are soluble in 1 cc. of water. At 100°C. 487 grams of sucrose are soluble in 100 cc. of water. For solubilities at other temperatures see Table 5.

In Table 5 the solubility of sucrose is expressed in two ways. In column 2 is given the amount of sucrose dissolved in water to make 100 grams of solution. Thus at 0°C, 64.18 grams of sucrose are dissolved in 35.82 grams of water to give a total of 100 grams of solution. The third column states the number of grams of sucrose dissolved in 100 grams of water at a definite temperature.

Table 5 Solubility of Sucrose in Water at Different Temperatures

(From Browne's "Handbook of Suzar Analysis")

 Temperature, degrees C. Grams of sucrose in 100 grams of solution, or per cent Grams of sucrose dissolved by 100 grams of water Specific gravity of solution 0 64.18 179.2 1.31490 5 64.87 184.7 1.31920 10 65.58 190.5 1.32353 15 66.30 197.0 1.32804 20 67.09 203.9 1.33272 25 67.89 211.4 1.33768 30 68.70 219.5 1.34273 35 69.55 228.4 1.34805 40 70.42 238.1 1.35353 45 71.32 248.7 1.35923 50 72.25 260.4 1.36515 55 73.20 273.1 1.37124 60 74.18 287.3 1.37755 65 75.18 302.9 1.38404 70 76.22 320.5 1.39083 75 77.27 339.9 1.39772 80 78.36 362.1 1.40493 85 79.46 386.8 1.41225 90 80.61 415.7 1.41996 95 81.77 448.6 1.42778 100 82.87 487.2 1.43594

Percentage of Sucrose in Saturated Solutions. From Table 5 the percentage of sugar may be obtained. At 0°C, 64.18 grams of sugar and 35.82 grams of water give 100 grams of solution, so that the number of grams of sugar may be read as percentage of sucrose or 64.18 per cent.

Maltose. Maltose is not a common sugar on the market. When used to make jelly, it crystallizes from the jelly, like dextrose. Gillis has reported the following solubility.

Lactose. The use of lactose in the home is limited because it is not very soluble and lacks sweetness. According to Greenleaf, if lactose is crystallized below 93.5°C. the alpha hydrate form is obtained. Above 93.5°C. the beta lactose is formed. Beta lactose is about one-fourth sweeter than alpha hydrate and dissolves more rapidly, hence does not leave a sandy sensation in the mouth. Hudson states that at the final solubility of lactose there are 11/2 parts of the anhydrous to 1 of the hydrate. Hunziker and Nissen state that its solution is complete after shaking it 170 hours at constant temperature. Herrington found that the addition of calcium chloride to a lactose solution increased the solubility of lactose from 28.6 to 29.5 grams per 100 grams of water at 32°C. An analysis of the precipitate showed the crystals to be a compound of lactose with calcium chloride. The following table of solubility of lactose is from Hudson.