45. Purpose of Rising.--Rising is an important part of the process of
bread making, no matter which method is employed. In a sponge, its
purpose is to blend the ingredients after they have been mixed, as well
as to permit the growth of the yeast; in a dough, after the gas has been
evenly distributed by means of kneading, the purpose of rising is to
permit the incorporation of a sufficient quantity of carbon dioxide to
make the bread light when it is baked. As has just been explained, three
risings are necessary in the sponge method of both the long and the
short process, whereas only two are required in the straight-dough
methods. The last rising, or the one that takes place after the dough is
shaped into loaves, is the one that affects the texture of the bread
most, so that it should receive considerable attention. If the dough is
not allowed to rise sufficiently at this time, the bread will be too
fine in texture and will likely be heavy; and if it is permitted to rise
too much, it will be coarse in texture. Allowance, however, should be
made for the fact that the rising will continue after the bread has been
placed in the oven.
46. Temperature for Rising.--As has been mentioned, the best results are
obtained if the bread dough is kept at a uniform temperature throughout
its rising. The temperature at which it rises most rapidly is about 86
degrees Fahrenheit; but, unless it can be watched closely, a better plan
is to keep it, especially if the long process of bread making is
followed, at a temperature that runs no higher than 80 degrees. Various
methods of maintaining a uniform temperature have been devised, but the
ones usually resorted to consist in placing the bowl containing the
sponge or the dough in a bread raiser, a fireless cooker, or a vessel of
hot water.
[Illustration: Fig. 4]
47. Bread raisers can be purchased, but if desired a simple
bread-raising device may be constructed from a good-sized wooden box. To
make such a device, line the box with tin or similar metal and fit it
with a door or a cover that may be closed tight. Make a hole in one side
of the box into which to insert a thermometer, and, at about the center
of the box, place a shelf on which to set the bowl or pan containing the
sponge or dough. For heating the interior, use may be made of a single
gas burner, an oil lamp, or any other small heating device. This should
be placed in the bottom of the box, under the shelf, and over it should
be placed a pan of water to keep the air in the box moist, moist air
being essential to good results. Where large quantities of bread must be
baked regularly, such a device will prove very satisfactory. The
temperature inside should be kept somewhere in the neighborhood of 95 to
105 degrees Fahrenheit if the bread is to rise rapidly; but it may be
kept from 80 to 95 degrees if slower rising is desired.
48. Placing the bowl containing the dough mixture in a larger vessel of
hot water is a simple and satisfactory way of obtaining a uniform
temperature, being especially desirable for a sponge in the quick-process
sponge method. The water in the large vessel should be at a temperature
of about 110 to 115 degrees Fahrenheit. After the bowl of sponge or
dough is placed in the water, the large vessel should be covered very
carefully, so that the heat from the water will be retained. To maintain
the temperature in the vessel and thus keep it right for the bread
mixture, the hot water has to be replenished occasionally. If this is
done, the sponge or dough will be maintained at a temperature of about
90 degrees and will therefore rise rapidly.
[Illustration: Fig. 5]
49. To insure the best results with the rising of bread mixtures, it is
advisable, for the beginner at least, to use a thermometer for
determining the temperature of air or water, as this instrument will
save considerable time until experience in judging such matters has been
gained. A Fahrenheit thermometer like that shown in Fig. 4 is the ideal
kind for use in bread making. As an aid in this process, there are
indicated in this illustration the temperature at which dough should be
kept for rising and the temperature at which water should be kept
outside the bowl to maintain a temperature of 75 to 90 degrees in the
dough when the plan mentioned in Art. 48 for keeping dough at a uniform
temperature is followed. In addition, the oven temperatures for baking
bread and rolls, which are explained later, are also shown. The
temperature of water can, however, be determined fairly accurately with
the hands. If it feels very warm but does not burn the hand, it may be
considered at about a temperature of 110 to 115 degrees.
In order to prevent the formation of a hard surface on the dough, the
bowl in which it rises should be kept tightly covered. A further means
of preventing this condition consists in oiling the surface of the
dough; that is, brushing it lightly with melted fat. In case a crust
does form, it should be well moistened with water or milk and allowed to
soften completely before the next kneading is begun.
[Illustration: Fig. 6]
50. Time Required for Rising.--No definite rule can be given for the
length of time required for dough to rise, for this depends entirely on
the activity of the yeast. If the yeast is active, the dough will rise
quickly; but if it is not of good quality or if it has been killed or
retarded in its growth by improper handling, the dough will rise slowly.
Usually, dough should be allowed to rise until it has doubled in bulk. A
good way in which to determine when this takes place is to put a small
piece of the dough in a glass, such as a measuring glass, a tumbler, or
a jelly glass, and mark on this glass where the dough should come when
it has increased to twice its size. This glass set beside the vessel
containing the dough will show when it has risen sufficiently. This plan
is illustrated in Figs. 5 and 6. Fig. 5 shows a glass half filled with
dough and a bowl of bread dough ready to be placed where they will keep
warm for the first rising; and Fig. 6 shows the same dough after it has
doubled in bulk, as is evident from the fact that the glass is
entirely full.