Whenever we post a recipe (particularly a baking recipe) exclusively with weight measurements, commenters request volume measurements.
And that makes sense: Not everyone has a kitchen scale, and so it's most inclusive to list measurements in volume and ounces (and grams, too). Yet many making baking experts (Alice Medrich, for one) would insist you invest in one.
"Too much flour is one of the top reasons for tough, hard, dry cookies and cakes that resemble doorstops," says Alice, pointing to the most notorious baking culprit in the weight-versus-volume debate: Every time you measure flour using a volume measure—even if you always use the scoop-and-sweep method or you always use the lightly-spoon-it-in method—you're likely to get a different amount. It depends whether you aerate the flour; whether you tap on the cup as you go; whether you tend toward a heavy hand; and whether Mercury is in retrograde.
And that's just the variance in your own measurements: If you spend enough time thinking about how cookbook writers and recipe testers measure flour (maybe they specify in the notes, maybe they don't), and if it's the same way you do, and you just might go crazy.
But wait! There's more. Yet another reason to bake using a scale? Every measuring cup holds a slightly different amount. (When you think about how difficult—and how important, and how expensive—it is to manufacture accurate and precise equipment for science labs, this makes sense.)
To prove it, I collected one-cup measures from the homes of the Food52 team. (That pink My Little Pony-esque one belongs to Clare Slaughter, and you'll have to ask her where she got it.)
I weighed each cup on its own, tared the scale, then scooped it into a bucket of granular sugar and bulldozed the top with the flat side of a butter knife (I figured that there's less divergence in sugar-measurement technique, and it's composed of fine granules that settle fairly evenly).
The results ranged from 6.81 ounces (193 grams) to 8.08 ounces (230 grams).
While this might not have a significant impact when you're measuring sugar (sugar's somewhat flexible, we've learned), imagine how it could change the results if you're measuring cups and cups of flour—and this is assuming that you're measuring it the same way—and in the way the recipe writer intended!—every time.
Doesn't weighing seem easier and more accurate?
Okay, so measuring cups aren't standardized, but are there some that are closer than others to the amount of sugar generally accepted to equal "1 cup"?
It's interesting that the cup measure that yielded a weight closest to 7 ounces—the metal measure in the center of the top row—is practically identical to the one that yielded the weight farthest from 7 ounces. If you think your measuring cup is accurate because it's humble and metal, think again.
The measuring cups that are hardest to use are, understandably, those that have an inner line indicating where the sugar should reach (for these, you can't even use a knife to even off the top—it's guesswork). Other than that, results were a toss up.
Should you despair, then, when you come across a recipe that lists only volume? Maybe? But not necessarily. Do enough baking and you'll get to know your measuring cup over time (and to be able to recognize when a dough or batter needs more or less flour). Seek out information on how the recipe's author typically measures ingredients (in the preface to David Lebovitz's Ready for Dessert, for example, he
admits to says he uses the scoop-and-sweep flour method) . Or pick a standard conversion chart—you might stick with King Arthur Flour's list—and calculate your own conversions (calculator permitted). See what works (and doesn't) and tweak accordingly.
And assume, I'd think, that for old, simpler recipes that don't list weight, volume (and its quirks and variations) is okay—and that for complicated, high-maintenance beauties (like macarons and sponge cakes), weight will be listed (and abided by!).
Have we convinced to invest in a kitchen scale yet? And then once you've got it, you'll want to check it for accuracy (but that's a whole other story...):
Do you have a favorite site of measuring cups? Or a hunch they're not accurate? Tell us in the comments!