There are two types of cooks in the kitchen—okay, there are many, but for this post, there are two:
there are those that measure their ingredients, and
those who eyeball it.
Let me break food blogger protocol and answer the main question right up front, do you really need to measure your ingredients when cooking? For low carb and keto recipes, I’d argue, yes. If you want to get into ketosis or track your carbs in any meaningful way, then you need to measure your ingredients.
But, and this is a BIG BUT, you will never be 100% accurate—more on that later—and that’s okay. Remember, bodies are smart, but they’re also dumb. So, it may be able to tell the difference between eating 150 carbs a day and eating 20 carbs, but an extra carb here or there won’t break your entire system.
Now, if you read our introduction to kitchen measurements, you know my feelings on the volumetric versus weighing ingredients kitchen debate. If you didn’t, let me recap, I’m strong camp weigh them out.
One of my biggest kitchen victories was getting Kaitee to not only start writing down what she puts in recipes she’s experimenting with, but to actually measure out the ingredients. That said, she does have a weirdly good ability to eyeball cheese measurements accurately. It’s like her everyday superpower.
Anyway … now that you know that this post is very much pro measuring your low carb recipe ingredients, let’s go down the rabbit hole that is “Measuring Accuracy” versus “Practical Accuracy” when it comes to cooking.
Measuring Accuracy When Cooking
In the kitchen, measuring accuracy refers to how consistently and repeatedly you can measure some ingredient.
In theory, As long as the proportions are the same, it doesn't matter if you use volume or mass measurements. However, this assumes that the densities of whatever you're measuring are constant. Sure, this assumption works very well with liquids, but not so much for solid ingredients.
Take any fine dry ingredient—like almond or coconut flour—the mass of a volume measurement—like 1 cup—could vary by +/- 20% depending on if it’s compacted or sifted.
So, let’s say you need 1 cup (112 g) of almond flour, which accounts for 20 carbs in your recipe. You pull out your measuring cup, pack it to the line, and call it a day. The issue is you may have unknowingly added 20-22 extra grams of almond flour—adding almost 4 additional carbs to whatever you’re cooking.
This is straight-up not acceptable in terms of reproducibility.
If you look at professional-level baking books, they often give mass measures instead of volumetric measurements. If volumetric measures are there, I'm 99% certain they're there to appeal to our lazy American cooking ways.
Coconut oil is another great example. I live in a place where it's cold 9 months out of the year. What does this have to do with coconut oil? Well, coconut oil has a melting point of somewhere around 75 degrees F, so it's usually mostly solid when I decide to use it.
Measuring out, say a 1/4 cup of solid oil is a bit of a challenge because it doesn't completely fill the cup, so it’s not as much oil as you intended to measure out. Ultimately, it’s easier to just cut out 55 grams worth of oil with some arbitrary—easier to clean utensil—instead.
Practical Accuracy When Cooking
What is practical accuracy? Practical accuracy when cooking is getting things close enough. It’s sort of like when you get a feel for a recipe you’ve made so many times where you just know how much to add to something by some intuition. I recognize the counter-intuitiveness of mentioning “feelings” when we’re talking about being objectively accurate but bear with me.
I do lots of math and statistics at my day job. So (instrument) precision is something that I’m always thinking about, despite my other lazy tendencies. As nice as it'd be to be absolutely precise on everything, that's a theorist's game, and I’m not too keen on a world of perfect vacuums and spherical everything.
It is possible to be precise to a fault—hence the whole concept of significant figures in your math/science courses—and it's a real easy way to stress yourself out, especially if math isn’t your strongest subject.
By the way, nutritional info on labels varies by around +/- 10%, so your counts may be off a bit already—and that's okay!
Your typical digital scale has a capacity of 5-ish lbs with a resolution of 1 gram. If you want sub-gram accuracy, you can use a small pocket scale but the trade-off is that it only has a few hundred-gram capacity. Unless you have real deep pockets, you're not going to find a high capacity, high precision all-in-one solution.
If you want to measure 2 grams of some liquid and you end up measuring out 3 grams.
How much are you off by?
Take 100 MULTIPLIED BY [ what you measured (3 grams) MINUS what you intended to measure (2 grams) ] DIVIDED BY what you intended to measure.
100 x [ 3 - 2 ] / 2 = 50%
If you're off by 50%, that’s a lot.
Now let's suppose you're measuring a cup of water (237 grams) but you measure out 240 grams because—like me—you like nice numbers like multiples of 5 (see aforementioned lazy tendencies). What's the percent error?
100 x [ 240 - 237 ] / 237 = 1.26%. Which isn't so terrible.
The point illustrated here is that the scale—2 grams versus 237 grams—of what you’re measuring affects your error. The 1 gram resolution isn't that bad if you're measuring large quantities of food but definitely bad measuring small quantities.
Measuring these quantities is why I have two scales, one for large amounts, one for small quantities. Really, this was all an elaborate ploy to have math in my posts.
Here are the scales I use. Full disclosure, these are Amazon associate links.
For small amounts I use the AC Pro Digital Pocket Weight Scale.
I mostly use the large scale and I only really use the small scale for real small quantities of things that need to be precise, like:
You can play the same math games with sizes of numbers when you’re considering carbs or calories. Since Kait is low carb, we do try to be as precise as we can because we’re allotted only a little per day (e.g., 1 gram is 5% of a 20 gram daily allotment).
With calories, it helps to think in terms of how much the extra calories amount to compared to your daily goals, (e.g., an extra 5 grams of oil is a bit over 2% of a 2000 calorie daily allotment). This is not to say that you should ignore all those small variations in your measurements because if you’re consistently overshooting measurements, then you’re consistently overeating and those calories can add up.
The goal here is to relax a little bit and not fret over every single small thing. You can for some things, but doing so for every is exhausting, and taxing on your mental health.
At the end of the day, you have your numbers for your total calorie count + your macros. How do you get all of these little measurement and systematic nutritional info variations under control?
You keep tracking it.
Let’s focus on the calorie case. Realistically speaking—let’s say over a week—you’ll end up with an average number of calories per day. Because those days most likely varied, some days you’ll be up and some days you’ll be down from that average.
Mathematically speaking, the number of measurements that you have dictates how much your averages and errors change (the denominator in those equations). After all, keto and low carb is supposed to be a lifestyle change where you’re supposed to continue doing it when you’ve attained your goals.
Accumulating more and more data points shouldn’t be so tedious that you don’t want to do it. This is definitely an issue we’ve all ran into because sometimes keeping track of everything we eat can be overwhelming if you let it become a chore. Tracking is meant to help you, not add stress to your day.