FoodNet

Experimental cookery

1932

Page 284

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
If the bowl is inverted, the egg w^hite does not flow but remains in the bowl and the end of peaks stand up straight. If the egg is left to stand, the watery fluid collects at the bottom of the bowl more slowly. With longer beating the egg white appears dry, loses its shiny appearance, and small white patches that look like small curds may appear. This is the stage called dry in cook books. At this point the w^hite is very rigid and rather brittle so that with a whisk beater it is easily thrown out of the bowl in w^hich it is whipped. Methods of testing stiffness. There are several ways in which the stiff- ness may be tested. For household use the tests are ( 1 ) appearance, (2) the height of peaks and the extent to which the point bends over when the egg beater or some utensil is lifted out of the beaten white, and (3) the rate of flow when the bowl or plate in which the white is beaten is partially inverted. A skillful operator working constantly with egg w^hite soon learns to judge the degree of stiffness by these common household methods, and the degree of proficiency that can be attained is surprising. But for SALT AND WHIPPING OF EGG WHITES 347 experimental purposes the same degree of stiffness probably could not be duplicated in another laboratory from the description. In the home the height of the peaks, and particularly the extent the point falls over, is the best criterion for judging stiffness. The rate of flow is not quite so good unless the same quantity of egg white is always used, for a large quantity must be beaten stiffer to flow at the same rate as a smaller quantity. For laboratory purposes, (1) specific gravity, (2) foaming power, and (3) the amount of drainage during a definite time are used to test the stiffness and stability of the foam. Specific gravity is determined by divid- ing the weight of a given volume of egg white by the weight of the same volume of water at the same temperature. Barmore reports that foams with specific gravity of 0.15 to 0.16 yield good angel cakes. Bailey calculated foaming power by means of the formula : {^m)- 100 where F = foaming power of egg white, F = volume of dish in cubic centimeters, and IV = weight of foam in grams. The specific gravity of the original egg white was taken as 1.04. The stability of a foam may be tested by putting a given weight of foam in a funnel of known capacity and bore. The funnel is covered to prevent evaporation. If the funnel is placed in a graduated cylinder, the drainage may be read in cubic centimeters or the weight taken at the end of a definite time, usually 30, 40, or 60 minutes. When the egg white is not beaten sufficiently both the unbeaten egg white and the foam drain from the funnel. After a certain stage of beating is reached little drainage occurs. With still longer beating Barmore states the drainage increases. Work of students in the author's laboratory, Keltner, Hoskey, and Loaft, though not extensive enough to be conclusive, indicates that better angel cakes are obtained if a certain percentage of drainage occurs, the exact amount varying with different types of egg beaters.