Note: I recognize this is a tedious subject. And for that, I apologize.
"How many ounces are in ___?"
Some of the earliest memories I have of when Kait started keto involve this question.
“How many ounces are in ¼ cup?”
“How many ounces are in 4 tablespoons?”
“How many ounces are in a cup of whipping cream?”
This question may seem harmless, but when you’ve had an entire year of engineering courses on units and measurements, you begin to question things like that.
I could never give her an immediate straight answer. Why? Because, honestly, the answer is that it depends.
This frustrated her, and since I’m sure she isn’t alone, I wanted to write this guide to kitchen measurements.
Let's look at:
What is an ounce?
What are volumetric measurements?
What is a gram?
Grams versus Cups
Quick Reference Conversion Chart
What is an ounce?
Here is the crux of the issue. An ounce can refer to both fluid and mass measurements. Since the US insists on being difficult, the fluid ounce we generally refer to is not the same as the mass—or "avoirdupois" in fancy words people never use—ounce. For more information, here's a Wikipedia article on fluid ounces.
Sounds confusing, right?
You'd think 1/4 cup—which is 4 fluid ounces (fl. oz.)—of flour and whipping cream would be the same amount—both are 1/4 cup, but you'd be wrong.
If using fluid ounces to measure something like flour makes you feel weird. You’re not alone, that’s a huge reason I’m writing this post.
¼ cup of flour is roughly 1 mass ounce.
¼ cup of whipping cream is roughly 2.1 mass ounces.
These differences in density can add up if you're not careful and can be a major pain, especially when you're trying to get into ketosis.
The US has this nasty habit of using super-inconvenient units, especially in cooking. I'm looking at you, volumetric measurements.
What are volumetric measurements?
If you're in the US, then you are aware of the tedious fractions of teaspoons, tablespoons, cups, and pints that make up most recipes.
Those of you with leaders who don't fear the metric system are familiar with liters and the powers of 10 associated with such. And if you're Australian ... well, you just don't know what a tablespoon is.
On the one hand—visually speaking—it's good to know how much you're making of something and how it fills out a given container. On the other hand, various ingredients mixed together will dissolve, absorb, and expand.
So, if you were keeping track of total volume, you'd be hard-pressed to get an accurate tally of that, even when you're assuming a basic shape like a cube.
Theoretically, you can use anything in your kitchen, given you know the volume of the tool, but ain't nobody got time for that. One of the more clever ways people have taken advantage of this is the concept of recipes is in terms of "parts."
Basically, you take any arbitrary volume container and mix up things based on the numbers of that container.
For example: take a shot glass, you can mix a vinaigrette to something like 8 shots of lemon juice, 3 shots oil. It's a great concept that we'll delve into more later.
What is a gram?
A gram is a unit of mass defined as the mass of water that occupies one cubed centimeter at atmospheric, room temperature conditions.
At least it was until 2018 when they redefined the kilogram. You can read more about that here, but that's not important for our purposes.
The gram is simply a convenient unit of measure that we can use easily in the kitchen. Here in the U.S., we want to be unique using imperial units but everyone else in the world uses grams.
Grams Versus Cups
Many people think that volumetric measures are a faster way of measuring. However, when you start cooking, you'll quickly find that volumetric measurements don't actually save time if you’re not prepared.
In my opinion, the grams versus cups debate comes down to three things:
convenience
clean-up
scalability
I can't tell you how many times we didn't have the right measuring cups or spoons on hand. Sometimes we're lazy about cleaning, or they get lost, or we don't have enough of them. Kait and I are especially guilty about the cleaning one as we only have a manual dishwasher (aka me).
So, when you're cooking—and your kitchen isn't in perfect order—you end up wasting a lot of time locating, then measuring ingredients in the right tools and washing and repeating. So any promise of time efficiency afforded by volumetric measures quickly evaporates.
The digital scale wasn't patented until 1980, and analog scales were generally expensive and or inconvenient 40 years ago, but that's not the case anymore. Nowadays, you can find digital scales on Amazon for under $15.
Kait and I use scales because we find they are much easier to prep with. I don't have to find the correct cup/spoon to measure, and if I plan accordingly, I can just toss things into bowls/pans on a scale and get to the actual cooking faster. With the added bonus of less stuff to wash.
Plus, scaling recipes is much easier in mass units—like grams.
When using measuring cups, scaling up is easy if you double or triple a recipe. Scaling down is a little trickier because some measuring sets don’t include all the necessary divisions of cups and spoons.
For example: if you are scaling a recipe and you need ⅙ cup—which is half of a ⅓ cup—but your set didn’t come with a ⅙ cup—which no set ever does—you end up being forced to eyeball half of a ⅓ cup. This nightmare scenario could be avoided by using grams instead of measuring cups/spoons.
Long story short, I hate measuring cups and spoons because it usually ends up becoming a question of how to measure things versus simply measuring things.
Quick Reference Conversion Chart
Chances are you only opened this guide for some sort of quick reference conversion chart. So, here are some common keto ingredients measured in grams!
Remember, liquid and solids differ in density, which is why one cup of butter weighs less than one cup of heavy whipping cream.
Feel free to copy the spreadsheet above and add it to your drive for future reference.
I hope you enjoyed this engineer's rant about kitchen measurements. Though remember, ultimately, whatever method works for you is the right method. Never let anyone alienate you or gatekeep cooking.
Personally, I think measuring cups are garbage, but that's just me.
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