This section is from the book "Experimental Cookery From The Chemical And Physical Standpoint", by Belle Lowe. Also available from Amazon: Experimental cookery.
Waffles may contain the same ingredients as griddle cakes, though egg is never omitted as is sometimes the case in the latter. The proportion of flour may vary from 1 to 1 1/2 cups or more per cup of liquid, depending on the type of waffle desired and the proportion of other ingredients. In general, waffles are preferable with less flour than is used in griddle cakes, 1 1/3 cups to a cup of liquid being a good proportion for plain waffles. They also require less baking powder than griddle cakes.
In mixing waffles the egg whites may be beaten stiff and folded into the batter or the whole egg may be beaten until foamy and added to the batter. The former method generally gives the better results. The stirrer the batter the shorter the mixing period should be, if tender waffles are desired.
One quality that many people desire in waffles is crispness. This depends largely on the length of time the waffle is baked. A plain waffle made from 1 1/3 cups of flour needs to be baked about 4 to 5 minutes, though the exact time depends upon the temperature maintained by the iron and the depth of batter the iron will hold. However, a batter with a cup of flour to a cup of liquid needs to be baked longer, else the waffle is limp and soggy instead of crisp. Stiffer batters do not need to bake as long, but they are apt to give waffles that are somewhat bready and tough.
The rich waffles, containing a high percentage of fat and some sugar or molasses, that are used for shortcakes or desserts, may be better if baked a little more slowly than plain waffles. Waffles containing a good deal of sugar are often limp when first taken from the iron, but if baked long enough, they become crisp in a short time. Those that are used for short-cake should be baked long enough to remain crisp. Melted fat or oil added to the batter does away with the necessity of greasing an electric waffle iron. However, if the electric iron is too hot or too cold the batter may stick to it.