Why I use Metric Units and Scales when Baking, Even in The Land of Freedom Units

I’ll cut to the chase: using scales and grams for baking recipes is more accurate, it’s faster, and it means less cleanup. At home, I use an 11-pound baking scale from OXO that is no longer in production, but their new model has all the same functions. I also use a small coffee scale from Hario for measuring very small quantities.

• OXO Good Grips 11-Pound Stainless Steel Food Scale with Pull-Out Display
• Hario V60 Drip Scale and Timer

Let’s start with accuracy.

To demonstrate this, I measured out two separate cups of flour using two popular methods. The first I sifted, then spooned the flour into the cup before leveling it with the back of a knife. The second I used the “dip and sweep” method by scooping flour out of the bag with the measuring cup then leveling it.

The sifted flour weighed a little over 4 ounces (130g), while the dip-and-sweep flour weighed 5.25 ounces (160g)—a difference of over 25%.

In fact, in a more robust test I conducted years ago at Cook’s Illustrated using home cook volunteers as testing subjects, I found that when measuring by volume, cups of flour can vary between 4 ounces and 6 ounces—a full 50% difference!

This is a massive amount of variation and makes a correspondingly big difference in the consistency of your dough or batter, from overly stiff to downright soupy.

The point is: measuring flour by weight is far more accurate.

Measuring by weight has other advantages as well:

It’s faster. All you have to do is set your bowl on the scale, tare it, measure in your first ingredients, re-tare it, measure in your second, etc. No need to pull multiple cups and out of the drawer. It’s a simple, streamlined process. The only exceptions to this are ingredients added in such small amounts that a normal baking scale can’t measure them accurately. Think that quarter teaspoon of baking soda or a pinch of nutmeg.

It’s less messy. Instead of a half dozen cups and spoons to wash, all you’ve got is a single bowl—the same bowl you’d also have to get messy when measuring by volume. If you like to be very precise (which I often do), you’ll at most need one large bowl and baker’s scale and a smaller bowl and jeweler’s scale for measuring small amounts of ingredients (like salt and yeast).

And bonus! Most models sport a nifty backlit seven-segment display. I’m a fan of efficiency and smart technology, and the seven-segment display (you know, the kind you find on alarm clocks and… digital scales) are peak efficiency and smartness. They were invented in the early 20th century and are still useful nearly 125 years later. (I'm still waiting on a Technology Connections video about them)

So you tell me, but if I had the opportunity to get away with life only ever having to wash my torso and occasionally my big toe (while still staying clean), being faster, and sporting a nifty backlit seven-segment display on my forehead, I’d jump at the chance.

But Why Metric?

Why use metric units? What’s wrong with my good ol’ freedom units?

I’m not sure if you’ve noticed, but the U.S. ain’t exactly in great standing currently. But if that’s not reason enough to switch to metric for baking, consider baker’s percentages.

Any dough or batter recipe can be broken down into what are called baker’s percentages. The basic idea is that If we consider the weight of the flour to be 100%, we can express the weight of every other ingredient as a percentage of the weight of the flour.

For instance, if a dough recipe calls for 100 grams of flour, 2 grams of salt, 1 gram of yeast, and 55 grams of water, we’d say that the basic dough recipe is

• 100% flour
• 2% salt
• 1% yeast
• 55% water (also known as "55% hydration")

If we double that recipe to 200 grams of flour, the percentages remain the same. In fact, we can use any amount of flour we’d like, and by using baker’s percentages, it’s easy to figure out how to scale the other ingredients. This makes doubling, tripling, halving, 2.6’ing or π’ing a recipe relatively simple.

Percentages, which are based on a base-10 system, dovetail nicely with metric units, which also work in base 10. 1,000 grams to a kilogram, 1,000 milliliters to a liter, etc.

The U.S. Customary System (sometimes called the Imperial system) of volume measures is utterly confounding when it comes to scaling or dividing. A tablespoon is made of three teaspoons. A cup is made of 16 tablespoons. A quart is made of 4 cups, and a gallon is made of 4 quarts. An ounce is not even an ounce in the U.S.! You have to specify whether you are measuring ounces (a unit of mass) or fluid ounces (a measure of volume). A fluid ounce of water weighs 1.043 ounces, ferchrissakes!

It’s Harry Potter monetary system levels of silly. No, it’s worse. It’s quidditch rules levels of silly.

These days I write my recipes with all three units (volume, US customary, and metric) listed because I know there are still plenty of folks out there who don’t own or use a scale. But if you’ve got one, I strongly urge you to use the mass measures, especially when baking!

So how much does a cup weigh?

We’ve seen that a cup of flour can vary hugely in weight depending kn how it’s measured. Depending on your recipe source, the typical equivalency ranges from 120 grams per cup up to 145 grams per cup.

In all my recipes, I use an equivalency of 140 grams per cup, which is the equivalent of close to 5 ounces — the same equivalency that I’ve been using since my days at Cook’s Illustrated.

Whatever recipe you follow, make sure you know what equivalency they are using if the ingredients aren’t spelled out with mass in the first place. Or better yet, don’t use a baking recipe that doesn’t include mass measurements!

Which scales should I get?

The OXO scale has been a favorite of mine for over a decade now. It’s fast and accurate, slim enough to store on its side, and has a pull-out face so you can get easy readings even with a large bowl on top of it.

The Hario V60 scale is what I use for coffee. It measures in grams and has a built in timer, though if you don’t want any of the bells and whistles, any tiny jewelers scale can do the job of measuring small quantities.

• OXO Good Grips 11-Pound Stainless Steel Food Scale with Pull-Out Display
• Hario V60 Drip Scale and Timer

Do any of you have other tips or tricks for speeding up the baking process or making it more foolproof?