When following a soap recipe, are the ounces measurements by weight or volume?
This is my recipe
24 oz canola
18 oz coconut oil
6 oz cocoa butter
6 oz castor oil
16 oz olive oil
9.8 oz lye
21-23 oz water
"oz" or "ounce" ALWAYS denotes weight. "fl. oz." ALWAYS denotes volume. Professional bakers rarely use measuring cups. Weight is a much more accurate method when measuring ingredients. Bakers will even weigh their water and milk. This is because of density differences. I would imagine that soap making is much like baking. The recipes work because of chemical reactions between ingredients. So, its crucial to be accurate and to have the right ratio of ingredients.
Part of the confusion lies in the fact that people use an abbreviation of "fluid ounce" when they refer to cups. You always hear people say, "There are 8 oz. in a cup". This is not necessarily correct. Cups have fluid ounces, not ounces. A cup of lead pellets and a cup of feathers both occupy 8 fluid ounces of volume. The lead will weigh a lot more than 8 ounces on a scale, the feathers will weigh a lot less than 8 ounces on a scale.
Here is another example:
8 oz of mini marshmallows = 4.54 cups
8 oz of flour = 1.81 cups
8 oz of sugar = 1.13 cups
As you can see, the weight of these ingredients are the same, yet their volumes are different. This is because of density differences. 8 oz does not always equal 1 cup. There are exceptions. "A pint is a pound the world around, for butter, eggs, milk and water". In other words, a cup of any of these ingredients will weigh about 8 ounces on a scale.
A lot of people are also confused about the term "dry measure". A dry measure is a measuring cup that is flat on top so that it can be leveled. A liquid measure is a measuring cup that has a spout on it. Both a 1 cup dry measure and a 1 cup liquid measure have exactly the same volume: 8 fluid ounces. A lot of people mistakenly believe a dry measure uses a different type of ounce. They will erroneously refer to it as a "dry ounce" or "solid ounce"…. or the will refer to liquid being measured in a cup as "liquid ounces".
Don’t let the term "fluid ounce" throw you off. Volume is the amount of space an ingredient occupies. So "fluid ounce" is simply a name for a unit of volume. It doesn’t matter if the ingredient in the cup is a dry ingredient or a liquid ingredient…. it is still fluid ounces.
Not all liquids have a density such that a cup of the liquid will weigh 8 ounces. A cup of water will vary in weight depending on the temperature of the water. A cup of alcohol will weigh less than 8 ounces on a scale. A cup of honey will weigh more than 8 ounces on a scale.
The soap recipe you posted is supposed to be weighed out… unless the author of the recipe really screwed up and meant fluid ounces.
admin on December 31st 2009 in soap recipes
postres20022000 responded on 31 Dec 2009 at 7:07 pm #
that all depends on what you are measuring…
References :
Betty responded on 31 Dec 2009 at 7:15 pm #
"oz" or "ounce" ALWAYS denotes weight. "fl. oz." ALWAYS denotes volume. Professional bakers rarely use measuring cups. Weight is a much more accurate method when measuring ingredients. Bakers will even weigh their water and milk. This is because of density differences. I would imagine that soap making is much like baking. The recipes work because of chemical reactions between ingredients. So, its crucial to be accurate and to have the right ratio of ingredients.
Part of the confusion lies in the fact that people use an abbreviation of "fluid ounce" when they refer to cups. You always hear people say, "There are 8 oz. in a cup". This is not necessarily correct. Cups have fluid ounces, not ounces. A cup of lead pellets and a cup of feathers both occupy 8 fluid ounces of volume. The lead will weigh a lot more than 8 ounces on a scale, the feathers will weigh a lot less than 8 ounces on a scale.
Here is another example:
8 oz of mini marshmallows = 4.54 cups
8 oz of flour = 1.81 cups
8 oz of sugar = 1.13 cups
As you can see, the weight of these ingredients are the same, yet their volumes are different. This is because of density differences. 8 oz does not always equal 1 cup. There are exceptions. "A pint is a pound the world around, for butter, eggs, milk and water". In other words, a cup of any of these ingredients will weigh about 8 ounces on a scale.
A lot of people are also confused about the term "dry measure". A dry measure is a measuring cup that is flat on top so that it can be leveled. A liquid measure is a measuring cup that has a spout on it. Both a 1 cup dry measure and a 1 cup liquid measure have exactly the same volume: 8 fluid ounces. A lot of people mistakenly believe a dry measure uses a different type of ounce. They will erroneously refer to it as a "dry ounce" or "solid ounce"…. or the will refer to liquid being measured in a cup as "liquid ounces".
Don’t let the term "fluid ounce" throw you off. Volume is the amount of space an ingredient occupies. So "fluid ounce" is simply a name for a unit of volume. It doesn’t matter if the ingredient in the cup is a dry ingredient or a liquid ingredient…. it is still fluid ounces.
Not all liquids have a density such that a cup of the liquid will weigh 8 ounces. A cup of water will vary in weight depending on the temperature of the water. A cup of alcohol will weigh less than 8 ounces on a scale. A cup of honey will weigh more than 8 ounces on a scale.
The soap recipe you posted is supposed to be weighed out… unless the author of the recipe really screwed up and meant fluid ounces.
References :
professional chef
culinary school grad
28 years in the industry