Volume, Volume, Volume

• When you prepare a recipe calling for measurements in units such as cup and tablespoon, you are baking based on volume measurements. A cup measures the amount of space an ingredient takes up, as opposed to its weight, so a cup of flour will take up the same amount of space -- and have the same volume -- as a cup of oil, even it though it might feel lighter. For this reason, the same measuring tool can be used for both liquid and solid ingredients. The one key point to remember is that for liquid ingredients, volume is sometimes measured in fluid ounces, with 8 fluid ounces equal to 1 cup.

Dry vs. Liquid Containers

• The primary difference between measuring vessels designed for dry ingredients and those designed for liquid ingredients is ease of use. You can use a dry measuring cup for a liquid and still get an accurate measurement, but you are likely to spill over the edge of the cup. For dry ingredients, however, the top of the cup is the exact amount of measure, so you can level the ingredient with a flat surface to ensure a more accurate measurement. In the same vein, a liquid measuring cup typically features lines that equal the exact amount of the measure below the lip of the vessel, allowing you to pour the liquid just to the line without risking spilling. For dry ingredients, this prevents you from leveling the measure, and you must rely more on eye-balling than accuracy.

A Weighty Issue

• Professional bakers typically measure liquid and solid ingredients by weight to ensure accuracy in their recipe preparations. When you measure out ingredients on a scale, everything is in proportion to the recipe's ratio, and your margin of error is reduced. For example, if you measured a cup of flour from a bag that had settled significantly, there would be a greater flour-to-air ratio than flour from a recently fluffed up batch. When you weigh flour, though, a pound equals a pound, regardless of the density. The important thing to remember when measuring ingredients by weight, rather than volume, is that there is not a direct relation between the 8 fluid ounces of a cup and 8 ounces. The only ingredient for which such a direct correlation is accurate is water. To get accurate measurements, use a recipe already written by weight, or consult a chart of volume to weight conversions for each ingredient.

A Matter of Scale

• Consider the size of your recipe when deciding whether to use volume or weight measurements for your solid and liquid ingredients. If you are making a smaller recipe, you will be measuring fewer times, giving you fewer opportunities to inaccurately measure. For example, if your recipe calls for 2 cups of flour and you are using a 1-cup dry measuring cup, you will have only two opportunities to incorrectly measure the flour. However, if your recipe calls for 8 cups of flour and you are using the same cup, you will have eight opportunities to incorrectly measure. Additionally, if you are preparing a recipe for a baked good that is notoriously finicky or difficult, even the slightest deviation from the correct amount of ingredients can throw off the whole process and ruin the final product. In deciding whether to measure your liquid and solid ingredients by volume or weight, remember that consistency is key and you should use either one method or the other.