Without an oven thermometer, there is no accurate means of determining the temperature of the oven; but housekeepers resort to various means to form a judgment about it.  The baker’s old-fashioned method is to throw a handful of flour on the oven bottom.  If it blackens without igniting, the heat is deemed sufficient.  Since the object for which the heat is desired is to cook the flour, not to burn it, it might be supposed that this would indicate too high a temperature; but the flour within the loaf to be baked is combined with a certain amount of moisture, the evaporation of which lowers the temperature of the bread considerably below that of the surrounding heated atmosphere.  The temperature of the inner portion of the loaf cannot exceed 212 deg. so long as it continues moist.  Bread might be perfectly cooked at this temperature by steam, but it would lack that most digestible portion of the loaf, the crust.

A common way of ascertaining if the heat of the oven is sufficient, is to hold the bare arm inside it for a few seconds.  If the arm cannot be held within while thirty is counted, it is too hot to begin with.  The following test is more accurate:  For rolls, the oven should be hot enough to brown a teaspoonful of flour in one minute, and for loaves in five minutes.

The temperature should be high enough to arrest the fermentation, which it will do at a point considerably below the boiling point of water, and at the same time to form a shell or crust, which will so support the dough as to prevent it from sinking or collapsing when the evolution of carbonic acid gas shall cease; but it should not be hot enough to brown the crust within ten or fifteen minutes.  The heat should increase for the first fifteen minutes, remain steady for the next fifteen minutes, and may then gradually decrease during the remainder of the baking.  If by any mischance the oven be so hot as to brown the crust too soon, cover the loaf with a clean paper for a few minutes.  Be careful that no draught reaches the bread while baking; open the oven door very seldom, and not at all for the first ten minutes.  If it is necessary to turn the loaf, try to do so without bringing it to the air.  From three fourths of an hour to an hour is usually a sufficient length of time to bake an ordinary sized loaf.  Be careful not to remove the bread from the oven until perfectly done.  It is better to allow it to bake ten minutes too long than not long enough.  The crust of bread, when done, should be equally browned all over.

The common test for well-baked bread is to tap it on the bottom with the finger; if it is light and well done, it will sound hollow; heavy bread will have a dull sound.  A thoroughly baked loaf will not burn the hand when lifted upon it from the pan.