Forum

I been using my meauring cups less and less as I switch to weighing my ingredients for baking but I still use them for other recipes like casseroles, etc.  But recently I discovered while using a 1 cup measuring cup on my scale to weigh out a cup of sugar that when I added enough sugar to reach the correct weight my measuring cup was only about 7/8 full.  This measuring cup came from a Nordic Ware plastic set.  I also have my old Tupperware plastic set I've used for years and haven't tested yet.  But it made me wonder if all those years before I started weighing my baking ingredients how far off I was on measuring out the correct amounts of ingredients.  Not only do you have the issue of how you fill the measuring cup (scoop vs. spoon in), especially for flour, but now I might have to worry if the basic set of measuring cups is even accurate for things like sugar.  Has anyone else run into this or tested their measuring cups on a scale with various ingredients?  That will be my next project I guess.  At least this makes me feel better about old baking failures, I can always tell myself it wasn't me but the inaccurate measuring cups.

Your cups may be off and your scale may be off. You can test each using a known quantity of water. 8 fluid ounces of water weighs 8 ounces. This is not true for other liquids like syrup or oil, but water is 1:1.

You could test both the scale and the measuring cup with a measure of water from a liquid measuring cup you think is reliable.

And of course, remember to tare your scale with the measuring cup on it.

There are many articles about lack of accuracy of measuring spoons and cups, including one in the Washinton Post citing inaccuracy up to 15%! Then again, thinking back to generations ago, recipes were made with actual tea cups and spoons, and baked with a wood fire. Two ends of the spectrum

Add in the fact that most online unit converters will tell you that 1 US cup = either 237 or 240 mL  (and NOT 250 mL as typically given in recipes providing imperial and metric values) and it further explains why I also am weighing dry ingredients when baking more often.  I have also been testing the measurement markings on butter sticks against their masses....my cut pieces often do not match the mass expected.  And re: produce, a recent bag of carrots contained carrots the size of bowling pins!  I often search "expected yield of 1 medium carrot" (or whatever produce called for) and weigh my stuff.  And, as someone who mostly cooks for 2 (at least until company is allowed again!), it is far easier to scale ingredients back when given masses for various ingredients. My little digital scale was around $20.00, has a tare function, weighs in both grams & ounces and is one of the long time workhorses of my little kitchen.   I just did a quick Amazon search and found many scales priced between $18.00 and $23.00 (CA).  

Of course, we just read a recent blog post about cooking without a recipe (which has long been part of both Canadian chef Michael Smith's message and Rachael Ray's eyeballing philosophy).  I for one spent time comparing "once around to the pan" and a "palmful" to the actual measurements she was describing.  I learned a lot in my early days of kitchen expts from TV personalities like these.  One last comment re: the carrot example - I suppose I am supposed to "know" how much I should add and more often than not now I do BUT but mistakes do happen...and when the final product tastes mostly of carrot and nothing else - I just wish they had given me a mass as a target amount.

The amount of sugar you had on the scale was 7 ounces or 198 grams?

A cooking class instructor who firmly believes in weights and ratios illustrated the problem by showing how the crystal structure and grind could affect the measure. Different salts and sugars had quite different weights for an "equal" volume.

One silly question: I have never used a kitchen scale, and since a typical recipe for a cake or quick bread calls for multiple measurings, i use multiple sets of measuring cups and spoons to prevent one ingredient from contaminating another.

Now how would that work when you use a scale? Powdery or grainy ingredients need to be put in something before weighing them, and you have to know the weight of the container. If you have to weigh multiple ingredients and use one receptacle for all of them, you end up putting one ingredient in another or you have to use a receptacle that is wet from washing. If you use multiple receptacles, they will have different weights and perhaps not be compatible with the scale. How does one deal with that?

And how much precision is necessary? Systems of weights and measures are arbitrary by their very nature. How is it that the optimal proportions of ingredients always conform to the customary units of a particular system? If I have a recipe that calls for 2 cups of flour, how is it that the optimal amount of sugar will always be precisely in some conventional unit of of the US customary system? For instance, why should it be one cup of sugar, no more, no less, or 1 1/4 cups of sugar, no more, no less? Instead of, say, 1 14/100 cups of sugar?

It would be the same with the metric system, and it would be the same by weight or volume.

With a scale you place the receptacle on the scale then push Tare which sets the scale to zero. Now the weight of the receptacle is removed. So you add your first ingredient until it shows the desired weight. If you have another ingredient that is being mixed with that ingredient e.g. you have weighed butter and are adding sugar, you click Tare again and now the scale shows zero again. You now weigh the sugar to the desired weight. And so on. All the ingredients that will be mixed together can be weighed in one bowl (less washing up).

You don't need to wash the receptacle each time when weighing - you can use anything for weighing since each time you are setting it to zero before you weigh your ingredient. So it can be a light plastic yogurt pot or a heavy china bowl - no matter as its weight is not counted.

The point about metric weights is that they are not arbitrary, they are constant. 100g of sugar is 100g of sugar whether it is coarse grain (like granulated) or fine grain (like caster/superfine). But 1 cup of granulated sugar is a very different weight to 1 cup of superfine sugar because of the difference in crystal size. The same applies to brown sugar - 1 cup of tightly packed brown sugar will be a different weight to a loosely filled cup measure. But 100g of brown sugar is the same amount of sugar no matter how packed it is.

This is why professional bakers only work with weights and why increasingly home bakers find scales much more accurate. A small difference in the amount of flour in a recipe can be the difference between success and failure. A cup of flour can weigh very differently depending on whether the flour is spooned in with air or scooped and pressed. As you can probably tell I am a great believer that scales are much better for baking (in fact all cooking).

The metric system may be based on 100, but no matter how neat it is in itself, it is arbitrary wrt biochemical realities. All numerical systems of weights and measures are. So if a recipe calls for 500 mL of one ingredient, the optimal amount of another ingredient may be 217.2 mL, or 344 mL.

Or if a recipe calls for 500g of one ingredient,  the optimal weight of another ingredient may be 318g. It would probably take a kitchen scientist to figure it all out. Or a very experienced eyeballer.

I always weigh ingredients when baking and find it incredibly frustrating that so many recipes only specify volumetric measurements, particularly for flour. How do I know what the author uses as the weight for a cup of flour? For instance, King Arthur Flour recipes use 4.25 ounces of flour per cup as their standard while Cook's Illustrated uses 5 ounces per cup.  It can make a huge difference!

If the authors of receipes don't say what they use for how much a cup of flour weighs, I use what is listed in The Baker's Appendix. The weghts listed in this book hit the average close enough that I have consistently good results.

Another ingredient that is pretty inconsistent in weight is brown sugar. I see a lot of receipes call for 1 cup packed brown sugar, but then give the weight the same as granulated sugar, 200 grams. I packed a few cups of brown sugar and got weights from 215 to 240 grams. Always more than 200 grams.

Would be nice if everyone who says that weight is most accurate could agree on what that weight is.