The Fresh Loaf

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Why Isnt a LB of Flour 16oz?

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BakingBachelor's picture
BakingBachelor

Why Isnt a LB of Flour 16oz?

When I used to make cost formulas for my recipes, I always figured 16oz was a lb, but with flour it is not, why is that?


 


Does anyone know of any other ingredients where 16oz of it is not a lb?

clazar123's picture
clazar123

16 ounces by weight = 1 pound whether it's dirt,gold,water,soda, or flour.


16 fluid ounces = whatever weight the substance weighs at. 16 fluid ounces of gold is definitely more than 1 pound by weight. 16 fluid ounces of butter is probably more than 1 pound by weight.


So, which ounces are you talking about? That is the key. When people write recipes, there is often a mix of the units used. THey may write ounces for liquid (6 oz water) and not indicate that it is fluid ounces-you are just supposed to know.Then they write "6 oz flour" and you are just supposed to know that this means "6 oz. by weight".


There have been many discussions here-some quite heated. You just have to know which "ounce" is being used.

BakingBachelor's picture
BakingBachelor

I guess I am referring to specifically what I once thought was "2 cups" is one pound. From looking at liquid measuring cups and seeing that 8oz of liquid is always 1lb.


But apparently a cup of flour is only about 4oz. It made me wonder how many recipes are using two cups of flour thinking 1lb, but yet they are really only using one cup.

Chuck's picture
Chuck

I've never heard the "2 cups is one pound of flour" rule of thumb before. Where did you get it from? In my experience this misunderstanding is so uncommon I'd not worry about it appearing in any recipes.


(IMHO, all these confusions [fluid ounces or ounces? cups or pound? any liquid or just water?] are great reasons for recipes to use grams [i.e. metric weights] instead. I even have a pocket scale with a resolution of 0.1 gram so I can measure everything, even yeast and salt for single loaves, that way. Soapbox please:-)

silkenpaw's picture
silkenpaw

Make room on your soapbox, so I can get on, too!

yozzause's picture
yozzause

I,m with you Chuck grams rule


I also use a pocket scale for  measuring salt  and small ingrediants, even dare i say it bread improver if need be, which can be .5 to .3 in bakers percentage terms and if you are making a small amount its great.I got mine on ebay NEW from China for $10 australian shipping included. I got a set for one of the chefs and he reckons its great for showing the students and his children what is in things like breakfast cereal by measuring out little piles of salt sugar etc that are listed on the packets.   


Yozza

PMcCool's picture
PMcCool

if you are talking about water, anyway.  And the right version of "pint" (there are more than one).  Using your example, 2 cups = 1 pint = 16 fl oz = 1 pound weight for water.  As other posters have noted, different substances have different densities than water, so there's quite a difference between 16 fluid ounces (a volume) of helium and 16 fluid ounces (the same volume) of lead.


Depending on type of flour and, more importantly, the individual doing the measuring, a cup of flour (volume again) might weigh anywhere between 4 ounces and 5.5 ounces (weight).  That's why you see so many admonitions here on TFL to use weight measurements for both liquids and solids.  In weight (more accurately, mass) terms, an ounce is an ounce is an ounce no matter who measures it.  Likewise with grams. 


Today I made three different breads.  One offered measurements in grams/ounces, as well as in volumes.  The other two were solely in volume measurements.  I had to do quite a bit of adjusting with those two to arrive at the right texture.  Apparently my cup of flour doesn't weigh as much as the recipe developers' cups of flour.  Although I grew up using volume measurements and was a late convert to weight measurements, I have come to appreciate and prefer recipes that use weights for ingredient measurements.  My odds of achieving something similar to the intended results are a lot better that way.


Paul

Davefs's picture
Davefs

Just to futhur pick nits,English units measure the pull of gravity which changes with elevation or what planet you are on.One pound at sea level weighs measurably less on mount Everest,even less on Mars,and still less on the moon,but waaay more on Jupiter(if it had a solid surface,and nearly nothing in orbit.


BUT,one kilogram has one kilogram of mass where ever you are.


To visualize it,consider a grand piano.easy to pick up on an asteroid with little gravity,but it would hurt just as much getting hit with it at a given speed as on Earth,because the mass is the same.


*End of nitpicking*


;-)

Mary Fisher's picture
Mary Fisher


"One pound at sea level weighs measurably less on mount Everest,even less on Mars,and still less on the moon,but waaay more on Jupiter(if it had a solid surface,and nearly nothing in orbit.


BUT,one kilogram has one kilogram of mass where ever you are."


 


So has a pound. 


An Imperial  pound always has 16 Imperial  ozs, that's a definition - not its volume.


Mary


Davefs's picture
Davefs

I guess I wasn't clear.I was strictly discussing weight,which is a measure of the pull of gravity and what pounds measure,vs mass,which is what metric measures.


That's why 100 pounds on earth WEIGHS 16 pounds on the moon.It's MASS,45.35 kg,is the same on Earth and on the moon.


Nowhere did I mention volume.


This may be a better explaination:


http://www.nyu.edu/pages/mathmol/textbook/weightvmass.html

Janknitz's picture
Janknitz

asks for X number of cups of flour, the recipe is written for VOLUME measurements of that ingredient.  Some recipes mix volume and weight--i.e. X number of ounces or grams of flour, plus 1 1/2 teaspoons of yeast and salt (because it's hard to accurately measure small amounts like that).  


If it asks for X number of grams, ounces, or pounds, it is written for WEIGHT measurements--use a scale.


What may be even more confusing is that the experienced bread bakers prefer volume measurements because they can calculate baker's percentages and easily scale the recipes up or down or determine the hydration level.  So we will often convert conventionally written recipes expressed in volume to weight.  But not every source or person agrees on the weight of a particular volume of each type of flour, making it even more confusing.  I've seen weights for a cup of AP flour vary by 60 or 80 grams.  You have to choose one source and stick with it for consistency's sake.  And you will see that each ingredient has it's own weight for a given volume.  


You made an erroneous leap.  Fluid ounces on volumetric measuring cups are based on the weight of water.  An equal volume of any other ingredient will weigh something else again--imagine a cup of lead shot--it's going to weigh a lot more than 8 ounces, even though it's volume is one cup.  So surmising that 1 cup of flour weighs 8 ounces and 2 a pound is wrong.  Volume is volume, weight is weight, UNLESS we are speaking about water, where they are roughly (not exactly, as it turns out) the same.  

Chuck's picture
Chuck

Quote:
...the experienced bread bakers prefer volume measurements...

I assume from the rest of your post that's a typo that was intended to say weight, right?-)

Janknitz's picture
Janknitz

Yes, that's a typo!  I meant to say bread bakers prefer weight.  Yikes!

clazar123's picture
clazar123

Cups measures volume and fluid ounces measures volume so you can always say that 1 cup of a substance is ALWAYS 8 fluid ounces of substance. So 1 cup of substance Y will always be 8 fluid ounces and 1 cup of substance X will always be 8 fluid ounces. In other words, 1 cup (8 fluid ounces) of substance X and Y is the same volume amount. 


What you CANNOT say is that 1 cup of any substance X and Y is always 8 ounces by weight bacuase they have different densities.1 cup of lead(8 fluid ounces) is a different weight(in ounces by weight) than 1 cup (8 fluid ounces) of flour.


Unfortunately, most recipes do not write the "fluid" in front of ounces and the "by weight" -we are used to communicating in shorthand. I wish different names were chosen for the systems involved but that happened a long time ago. So now we just have to make sure we state the correct units-just like my old math teacher used to say- or we suffer confusion.


A vote to do things in grams!


I've never seen a measuring cup that had 1 cup=1 pound. Interesting.This may be referring to water.


I hope this is helpful.


 

Nickisafoodie's picture
Nickisafoodie

Simply said, that is why there are dry measure cups and liquid measure cups. The two should not be swapped if you insist on using measuring cups vs. scales for bread recipes. 


Also there are plenty of posts that tell you how to convert dry and liquid measures into grams.  And yes whole wheat weighs more than white for a given "cup" and without regard to other variables like time of year, how it is stored, etc which can also affect weight. See this link:


http://www.nal.usda.gov/fnic/foodcomp/search/index.html


Some liquid pints are 16 oz, and the Imperial Pint (think "pint of Guiness" in the UK can be 20 oz) as was hinted at above...

GENE FOSTER's picture
GENE FOSTER

As most of us agree - better results with a scale.


I am slowly converting some of my quantities to grams - so much easier.


Just this week, I finally got tired of measuring 4 Tablespoons of shortening for biscuits  (special holiday treat) - converted to 70 grams.  So much easier and nowhere near as messy.


I just turned 68 and I find it no problem to use metric - just wish we (USA) had converted when I was a whole lot younger.  Just think, multiples of 10 and different units for weight and volume.  (I still use my 1/4 teaspoos, etc, because my scale does not accurately weigh small quantites)

Chuck's picture
Chuck

Quote:
(I still use my 1/4 teaspoos, etc, because my scale does not accurately weigh small quantites)

Check out the "Fast Weigh MS-500-BLK Digital Pocket Scale, 500 by 0.1 G" on amazon.com. I have one (two actually) and use it all the time to measure even very small quantities of yeast and flour for just one small loaf. The resolution of 0.1 gram (rather than the usual 1 gram) is sufficient (in fact it's the same as those "digital spoons"). It rests on the counter (no extra holding hand required like the "digital spoons") and the lid turned over makes a perfect "dish" for whatever's being measured. Best of all, it's only about $6 (plus shipping of course). Since I learned how to use it, I've completely quit using my measuring spoons.


(The category name [on amazon.com and elsewhere] is "pocket scale". amazon.com often has similar ones [wich I can't recommend either for or against as I've never used one] even a little cheaper, and the same one for double the price. Especially avoid the one packaged with a 100g calibration weight, for several reasons: why spend the extra money for a "package deal" that includes items you don't need; the built-in calibration is good and in my experience it doesn't drift, so there's never a need to recalibrate anyway; more importantly the 100g is the wrong weight [only a 500g calibration weight works], call up FastWeigh product support and tell them you have a 100g calibration weight and they'll tell you it's useless.)


(One warning: to save battery life it powers down automatically when not in use  ...fairly quickly. I haven't found it to be a problem. Then again I know that if I'm using the last of an old container then have to open a new container, to deal with opening the new container before I start measuring anything, otherwise it will "time out" with half a load waiting for me to start pouring the second half of the load.)


(The number sometimes changes a little: MB-500-BLK or MB-500 or M-500; once you find one you can identify duplicates by the picture, which it seems is always exactly the same.)


good luck!

GENE FOSTER's picture
GENE FOSTER

Chuck:


Many thanks, I ordered one today.


Gene

EvaB's picture
EvaB

but I do know that my mother said two cups of sugar was a pound, and that is what went into her pound cake, which is supposed to be made with a pound of flour, a pound of sugar and a pound of butter hence pound cake! Of course a pound of water or milk would also figure in there.


This I know because I had a recipe that was written just that way, and I didn't have a scale, so she said 4 cups of flour, and two of sugar, and since butter is sold in pound blocks of course a whole pound of butter, and she said add the liquid until it was thick batter consistancy, and it had of course some leavening and baked in loaf pans, and was one of the best tasting cakes I ever baked.


Of course she also had years of experience in cooking and cooked in resturants as well as at home, and she was a dip and scrape cup user, so obviously her cups of flour were closer to 4 ounces each than 3, she was very used to using her built in scale, which was to take something in each hand and decide which weighed less, she would hold a pound of butter or something with a known weight and compare the other to it, and be accurate to a fraction of an ounce, some people just have the nack, not me, and my brother could look at a space and tell you to a fraction of an inch what the measure of it was, even up to a mile, just having driven down a road once and sometimes years ago. My uncle once drove 15 miles, and cut a chunk of brass pipe off for a bearing, drove the 15 miles back and slipped it into place without so much as a piece of paper, or any measurement taken. He just knew!

Janknitz's picture
Janknitz

come equipped with all sorts of useful "equipment", don't we!


"she was very used to using her built in scale".


I inherited my own mother's "Momometer".  I can accurately tell my kids' temperatures with lips to the forehead.  I'm usually accurate within a 10th of a degree.  Much easier than those new fangled electronic thermometers, and no batteries needed.  ;o)

EvaB's picture
EvaB

she survived growin up dirt poor, the depression, marriage, three kids, the death of one at 9, living in a small town without a husband because she had left him, raising the kids on her own, a housefire, and general ill helth, and was usually quite cheerful, and upbeat. She was ingenious when it came to making do, and was always telling her kids and anyone else to go look up things in the dictionary and encyclopedias, she belived learning was key to keeping going, and she was a news junky when the news could take 3 months to several years to get out to the world.


She knew how to make up things that worked better than most medicines, how to cure a lot of childhood things and how to cut fabric to use the whole piece, and even if you didn't think you had enough to make the blouse you wanted.


Mother's just plain rock! My 33 year old daughter has finally come around to the fact that I really did know better! LOL

Mary Fisher's picture
Mary Fisher

Well it did seem as though you were suggesting that an 'English' pound had different physical properties from a kilogram. It doesn't. It doesn't have the same 'weight' or 'mass' but the proportional differences are the same wherever in the universe you are.


Not that you'd be able to measure either in some parts of the universe but that's a different matter.


Mary

Davefs's picture
Davefs

If this arcane subject is of inteerest to anyone this page


http://gwydir.demon.co.uk/jo/units/weight.htm


is cool and tells the history of all the measuements.It seems even in official circles there is disagreement  over weather a pound measures mass.Looks like some governmental bodies have over the years just declared that they measured the same thing.I was taught in physics class that pounds measure only the pull of gravity on an object and thus change with location.There also seem to be two terms called "pounds mass" and "pounds weight" .Whew!


Anyway,an ordinary kitchen or bathroom scale measures weight only,and will give different readings(even though they may be LABELED Kilograms)in different gravitational environments.You need a balance,such as the Doctor uses,with the sliding weights,to measure mass.It will give the same reading everywhere.


Of course that doesn't matter at all,since most of us live on Eath full time!

elyanqui's picture
elyanqui

I thought you guys were bakers.  Excuse me because most of you seem to be able to bake better breads tham me.  I have always used 'cups' of flour and 'cups' of water.  Recently on some website I can't recall, I was told you should tap the cup you are measuring the flour in to get it to settle.  How you 'measure' a cup has a great deal to do with how much flour is in the cup,  Try it!  Scoop up a cup of flour or add it by the spoonfulls however you normally do it. level it off and then tap the cup about 10 times with the back of a knife.  Howmuch does a cup of AP flour weigh?


 


 

Janknitz's picture
Janknitz

Not how I measure a cup, but how did the recipe writer measure a cup???  Some are scoop and sweep people, some are dump and level--and for things like flour yoou can get a wide variation of weight in the same volume depending on the method used.  So 1 cup by volume of flour in this recipe may not be the same as 1 cup by volume in that recipe.  How I measure flour may not match how the recipe writer did, and my results could be affected. 


Likewise, a lot of recipes call for "1 tsp. of salt".  What kind of salt?  If they meant sea salt or kosher salt, there's going to be way too much salt if you use table salt, or way too little if the opposite is true.  With weight measurements, it doesn't matter what type of salt is called for, because the weight will yield the same amount regardless of the type (OK, I know that the contents of the salt may change the saltiness, but I mean in general). 

Davefs's picture
Davefs

Agreed.The only way to get consistent results it a scale.It's not hard,why the resistance.

elyanqui's picture
elyanqui

Neither you nor I can be responsible for the way someone else measures their flour.  I just gave the way it should be measured.  This may be why they say to add a little flour or water a tablespoon at a time if the consistancy isn't right.  Needless to say, I bought a scale.  Now how much does a cup of flour weigh?


And as far as salt is oncerned, if the recipe does not state the type of salt, use table salt.

Davefs's picture
Davefs

"Neither you nor I can be responsible for the way someone else measures their flour." 


I have no idea what you mean by that.It's just weird.And obviously true.Did someone indicate that they were responsible for the way someone else measures flour?If so I missed it.


"I just gave the way it should be measured."


In your opinion.You're not likely to find a professional measuring flour with a measuring cup.BUT if for some reason you HAVE to use a measuring cup,sprinkling it in seems to work best,though I've never seen tapping recommended.


 " This may be why they say to add a little flour or water a tablespoon at a time if the consistency isn't right."


Even if it is the right amount of flour,other factors come into play,among them humidity and the particular flour used.


  "Needless to say, I bought a scale.  Now how much does a cup of flour weigh?"


Check the King Arthur flour site.They have a chart with the weights for everything from flour to salt to lard.


"And as far as salt is concerned, if the recipe does not state the type of salt, use table salt."


Most likely a safe assumption,but not guaranteed.

kbar's picture
kbar

I have been baking bread for about a year, and started right away using a scale. Usually I go with 130 grams = 1 cup of flour. Yesturday, since I had a Vitamix sitting in a closet, and a can of wheat kernals sitting on a shelf, that I would try grinding my own flour. After I ground it as fine as I could get it, I weighed a cup. I was pretty suprised to see it weigh in at a whopping 160 grams. I carefully measured it a couple more times. Yep, 160 grams. Would this be because of particle size? BTW it made great bread!

EvaB's picture
EvaB

than commercial flour, that it would weigh less, but its more likely that the wheat had more moisture than milled flour, so it weighed more after grinding.


I agree scales are great, I just used my new baker's pecentage scale, for my Xmas cakes, didn't use the percentage feature just the scale, and its a heck of a lot easier to weigh the cakes in the tin, than it was using my on the wall scale I've had for years.


I went with 140g per cup of flour for my flour, so the whole thing took 1120 grams of flour, for 8 cups, and I think it was a more accurate method than my used to be scoop and sweep or even the method I changed to spoon and sweep, the moisture was taken up by the flour just right, and it wasn't too wet (like some years) or too dry like others, so will simply add that into the list of ingredients and measure the flour that way the next time.

spacey's picture
spacey

Well, I bought a "kilo" bag of caputo flour last week, and when I poured it out onto the scale, it only read 960 g.  I don't care what the difference is in gravity, it isn't a variance of 4% between Italy and NYC, and it can't be covered by loss in travel.  I think the answer in my case is clearly that the source is dishonest.

Chuck's picture
Chuck

I can think of lots of "explanations" besides the source being dishonest, including:



  • flour was moister when it was packed, and it dried out a little during shipment

  • there's a large variation in package size -- even though "average" weight is right, any one individual package is probably either over or (in your case) under

  • different countries have different standards for how careful they are about weight


From your experience, I'd conclude that maybe the source was indeed a little dishonest  ...but then again maybe not (particularly given only a 4% difference). The U.S. enforces very high standards for weights and measures in trade; I'd not be at all surprised to hear that whole areas of the world are a little less scrupulous. If it took as much trouble as I suspect to find someone with the logistics to accept money from another country, then pack and ship internationally, I'd not be too picky about 4% shrinkage.

spacey's picture
spacey

I'm going to stick with dishonesty for now.  I bought 2 bags, and both were shy the same amount.  Not to paint with too broad a brush here (so of course, here I go painting wide!) but many italian products that are imporated to supermarkets here in the US seem to come with a markedly inferior quality, etc. to what's expected in Italy, based on conversations with people from there.  Given the scandals of italian "Olive" oil that is only passed through italy on the way to the US, with "lamp oil" quality oil sold as "extra virgin", etc. I don't think that a 40 gram difference in flour is that egregious.  However, it's so far 2-for-2. I think their consistency is fine, just not their ethics.

mrfrost's picture
mrfrost

Residue left in bag? Scale accuracy? Isolated case? User error?


Wonder what sort of loss other flours/brands would have, with this method of measuring?


Not a very scientific indictment. Sorry for your loss though.