What is the difference between weight and volume?
But a pound of brick is denser than a pound of feathers, and each one will look quite different
VOLUME is the space something takes up
Measuring by weight is more accurate
Consider castor oil compared to avocado oil 16 ounces of each will not weigh the same on the scale because castor is a much heavier oil
Advantages of measuring weight versus volume
It is more accurate, saving time and money
Ensures consistent results so every batch is the same
Eliminates the need for measuring utensils such as teaspoons, tablespoons and cups
Allows you to measure directly into one bowl using the container function, speeding up time and cleanup
It’s easier to scale a recipe by adding or subtracting ingredients as needed for each customized batch
Why is weight more accurate, you ask?
Because measuring cups and spoons are surprisingly inaccurate and can vary widely
Even worse, many inaccuracies creep into the recipe depending on what is measured and how you package the ingredients
For example, dipping into a box of cornstarch may have different measurements than spooning it because it may be packed differently into a cup
My cup of cornstarch on one batch probably won’t be the same as the next batch
Let’s say I pack a cup of cornstarch and the resulting amount by weight is 155 grams
Then I pack again for another batch but end up with 130 grams (25 gram difference)
That might not sound like much, but what if the recipe calls for 4 cups?
Often, when you measure by volume, the final weight of all components can be reduced by up to 10 percent or more
When dealing with soap making and cosmetic formulas, we’re dealing with chemistry, so it’s best to be as precise as possible for consistent results
In the US we use ounces and pounds, but we use almost the same terminology for weight and volume
For example, you might have 4 ounces of wax (weight) and 4 fluid ounces of almond oil (volume)
Looking at this in a real life scenario really shows the difference
Here are two photos of items that weigh the same
This is a net weight of 16 ounces
dried rose petals and buds behind 16 oz net weight
And for more detail, here are some examples of oils filled by weight into a container of the same size
Heavier oils like castor oil have a higher density (require less volume or space) than sunflower oil