When it concerns baking, accuracy in your measurements is an important to a recipe’s success, and the solitary most accurate way to measure her ingredients is by weight.

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I’ve obtained a few questions recently on few of my much more popular cake recipes that seem to suggest some confusion about weight matches volume measurements, specifically once it concerns measuring dry ingredients like flour. I figured I’d do a bit more in-depth explanation in a post, come hopefully clean up any confusion.

American bakers thrived up using cups, where a cup that water is equal to a cup that flour and also so forth. We also had it drilled into our brains the a cup is 8 ounces and a pint is a pound the human being round (a pint being 2 cups or 16 fluid ounces).

But I’m here to say the a pint is NOT constantly a pound and a cup is NOT always 8 ounces—it relies on what you’re measuring.

Now before you start arguing, allow me explain!

Weight matches Volume

Volume is a measure of the lot of an are something take away up. Things prefer cups that flour, gallons the milk, cubic feet the helium… these room all volume measurements.

Weight is a measure up of one object’s heaviness. Grams of salt, pounds that sugar, kilograms the apples… this are measurements of weight.

Ok. So, that provides sense, right? Volume and weight are measuring 2 entirely different things.

You’ve heard the old riddle: Which weighs more: a pound of feathers or a pound of lead?

Trick question: castle both sweet a pound! but the lead is going to have actually a lot smaller volume due to the fact that it is much more dense 보다 the feathers, for this reason it will look prefer a smaller amount the material.

When we’re talking around baking, the differences can not be fairly as apparent as feathers and lead, however the same is true that flour and water: one is much less dense than the other (in this instance the flour is the feathers and also the water is the lead). For this reason a lb of flour is going to take up more space, or volume, 보다 an indistinguishable pound that water.

An ounce of Confusion

Most that the confusion concerning weight and volume dimensions occurs once talking around ounces: an imperial unit of measure which have the right to be used to show both weight and volume. Liquid ounces refers to volume (like milliliters) whereas regular ounces describe weight (like grams). The fact that they space both called ounces, and not constantly differentiated by speak ounce/fluid ounce is one reason why they room so problematic.

Ounces through weight and ounces by volume are ONLY similar when you are measuring water or other liquids with a comparable density.

For example, 8 ounces that water by weight will certainly equal 8 fluid ounces by volume.

Flour, ~ above the other hand, is a entirely different ballgame and also a confound one come boot. No that you’d ever before measure flour with fluid ounces (which are just designed to measure—you guessed it—fluids), but, if you did, you’d discover that 8 liquid ounces that flour just weighs about 4 1/4 ounces. Weigh out 8 ounces that flour by weight and you’re going to have about 14 liquid ounces by volume. See exactly how confusing it is?

I mean, who carry out we have to petition come have liquid ounces readjusted to be referred to as something entirely different (flounces? frams? vols?) or, much better yet, ultimately just switch to metric prefer the remainder of the world?

Anyway.

Here space some visual comparisons to help illustrate this ide (keep in mind the you shouldn’t it is in measuring flour in a liquid measuring cup favor this, I just did so below so I could illustrate the differences between ounces through weight and also ounces by volume).

Both of this containers are holding 8 ounces.

On the left is 8 ounces of flour by weight, and on the ideal is 8 ounces of flour through volume (aka 1 cup).

If you weighed the 2 containers, the one on the appropriate would only weigh approximately 4 1/4 ounces.

Both of these containers room holding 8 ounces.

Weigh the end 8 ounces of flour and also 8 ounces of water on a scale and also this is what friend get. Visually it looks favor you have a lot more flour than water, but they weigh the precise same amount.

Both of this containers are holding 8 ounces.

On the left is 8 ounces the flour by volume and also on the best is 8 ounces the water by volume. Basically, what friend see right here is 1 cup of flour and 1 cup the water.

But if you placed these two containers ~ above a scale, the flour ~ above the left would just weigh 4 1/4 ounces, when the water would certainly weigh 8 ounces.

So, space you less perplexed yet? much more confused? i don’t blame you (lol).

My advice? as soon as you’re baking, forget ounces entirely. Pretend they don’t even exist. It just confuses things. Instead, emphasis on cup/tablespoon dimensions for volume, and also grams because that weight.

I’m trying to be much better about writing my recipes using simply cups and also grams because that this really reason, though you may still see ounces on older recipes or for things that are sold by the ounce, favor bars of chocolate or can be ~ of pumpkin.

Tip: when purchasing packaged or canned goods, if you’re unsure whether the ounce measurement on the package describes ounces by weight or liquid ounces, look in ~ the metric equivalent. If it’s grams (like on box pumpkin or chocolate bars), you’re managing weight. If it’s liters (like top top milk or wine) then you’re dealing with fluid ounces.

The beauty beauty of Metric

One that the beautiful things about the metric system is the there is no confusion. Grams space weight, milliliters space volume. If you watch grams, grab her scale. If you view milliliters, grab her liquid measure up cup.

Another genius aspect of the metric device is the it is calibrated come water: so once you’re measure up water or other liquids through a comparable density (like milk or orange juice), 200 milliliters will certainly weigh 200 grams. Cool!

However, as soon as you start measuring dried ingredients, which regularly have varying densities, the two numbers will not match.

1 cup the water weighs 236 grams.1 cup of flour weighs 125 grams.

The volume is the same, but the weight is various (remember: lead and also feathers).

One other benefit to making use of metric dimensions is accuracy: scales frequently only show ounces to the quarter or eighth of an ounce, for this reason 4 1/4 ounces or 10 1/8 ounces. Grams ~ above the various other hand, being a much smaller unit the measurement, make it easier to be incredibly precise. Precisely 236 grams that water is a much more accurate measurement than 8 3/8 ounces (technically 236 grams amounts to 8.32466 ounces but you’re no going to have the ability to measure that on a scale). The difference of 1/8th the an ounce is 3-4 grams, which might not seem choose much, yet it can include up.

A cup is a cup is a cup

… depending on what you’re measuring and how you measure it.

Liquids are pretty reliable. A cup is pretty much always going to it is in a cup.

See more: Name Something That Is Made From Milk, Dairy Product

But because that dry ingredients, flour specifically, the small granules that flour have the right to be compacted, essentially packing much more flour into the same amount of room (think about packing brown sugar, it’s a similar idea).

So depending on how friend measure your flour, if girlfriend fluff it and spoon it right into the cup, or if friend scoop directly from a bag the flour that has settled, her ‘cup’ may vary by as lot as 30% by weight, native 120 grams to upwards that 150 grams (!!) once you’re making a cake the calls for 3 cup of flour, that’s virtually an entire extra cup if you’re scooping straight from the bag. No wonder the cake is as well dry…