Why kitchen scale fluid ounce measurements are meaningless

I recently replaced the kitchen scale. The new one has all the features I was looking for. Negative tare is a big upgrade. But it also has two features that I never wanted and didn’t want. No one wants them. I’m talking about “milliliter” and “fluid ounce” settings, both of which are completely bullshit.

You see, I think it’s somehow crazy to explain this. Scale is scale. Weigh yourself. My scale is grateful that I can measure things in grams or ounces that I use most often. These are measures of weight. (Well, Gram measures massHowever, in general use on the kitchen scale on earth, this distinction is not important. )

On the other hand, milliliters and fluid ounces Volume. The measuring cup holds 8 fluid ounces. Disposable water bottles are usually 500 ml. These numbers indicate how much space is inside the cup or bottle.

Even if you know the volume of something, you don’t know how much it weighs. Emptying the water bottle and filling it with everclear, maple syrup, olive oil, sand, lead molten, and helium will not result in the same amount as when full. Water. The reason why the units of volume and weight are different is that they are not the same.

What is my scale doing when it says it is measuring volume?

So what do you think the fluid ounce function is doing? Well, it just weighs what you put on it, and assumes that the object is the density of water. I measured ounces of water (using the small measuring cup that came with the bottle of cough syrup), and the scale it was 1.0 ounces, 1.0 ounces, 29 ml, and 29 grams. He told me that.

Everything will check out. The density of water is 0.997 g / mL, which means 0.997 of Grams of water occupy 1 Milliliter Of space. Rounded off, 1 gram is roughly equivalent to 1 milliliter, and 1 fluid ounce is approximately equivalent to 1 (weight) ounce. If you need to add 4 ounces of water to your recipe (half a cup), go ahead and weigh 4 ounces. However, no “fluid ounce” setting is required to do this. You can weigh four regular (weight) ounces.

When measuring water, etc., the fluid ounce and milliliter settings are redundant. These only duplicate what is conveyed by the usual ounce and gram settings.If you are measuring something you do No It has the same density as water, such as alcohol, oil and syrup. The ounce and milliliter settings are worse than useless. They can guide you to put the completely wrong amount of ingredients in your recipe.

How big a difference does this make in the real world?

The test measured one “fluc ounce” of whiskey and one “fluid ounce” of log cabin maple flavored pancake syrup.

Alcohol has a much lower density than water, 0.789 g / mL.That means it’s lighter than water, it explains why you need to mix Mixed drinks-otherwise alcohol will float on top. My cheap whiskey was 90 proof (45% alcohol). This means that the actual density is heavier than pure alcohol, but still much lighter than water.

On the other hand, for syrup taller than It is denser than water because the sugar is dissolved and it gains weight without increasing its volume too much. If you’ve ever made a simple syrup, you know this. 1 cup of water and 1 cup of sugar is the sugar you combined with water. Pancake syrup contains much more sugar than simple syrup, so it is much heavier than water.

The image at the top of the page shows my results. Both cups were determined by scale to contain one “fluid ounce” of liquid. They are obviously not the same volume. I measured them with my little medicine cup: Whiskey (left) is 36 milliliters, or 1.22 fl oz. The syrup (right) is 22 milliliters, or 0.74 fl oz.

So if you’re making a mixed drink for four people and decide to use a scale instead of a jigger to measure a total of 6 fl oz (1.5 ounces per person), the drink will be much stronger than expected. increase. 1.83 ounces per person.

On the other hand, if you are following A cake recipe that requires 3.5 ounces of maple syrup If you use a scale instead of a measuring cup, you will only put 2.55 ounces of syrup in the cake. The result is not as sweet as intended.

(I know the maple cake recipe only says “ounces”, but the UK version Requires 100 ml, This is about 3.4 ounces of liquid volume. I also used the actual maple syrup density 1.37 for the calculation, which is very similar to the fake syrup 1.31 measured in my own experiments. In case one of my old chemistry professors is checking my work. )

Syrups and alcohol are extreme examples and that’s why I chose them. Here are some other common liquids that offset measurements:

• Oil is a little lighter than water (0.917 mg / mL for olive oil)
• Milk is slightly heavier than water (1.04 mg / mL)
• Peanut butter is a little heavier than water (1.1 mg / mL)
• Honey is much heavier than water (1.4 mg / mL)

So what should you do? Well, if you are measuring water, any setting will work. If you want to measure another type of liquid, use volumetric measurement. It can be a measuring cup, a measuring cup, or a tablespoon (1 tablespoon is half an ounce of fluid).