Mar 23, 2009 10:10 AM
Discussion

### Fluid ounces vs. weight

When a recipe calls for liquids and gives it in oz, does it mean does it mean fluid oz or weight? Is there a standard?

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1. Liquids are measured in fluid ounces.

4 Replies
1. re: alwayscooking

Thanks--that's what I had been doing but then I started reading more boards and getting confused. I was wondering if I'd been doing it wrong all along.

1. re: alwayscooking

That's not always true as recipes in baking formulas (ie; bread) are always in weight in order to maintain ratios.

1. re: Den

In those cases, aren't weights given in grams, then? IIRC, water weight in bread recipes aren't in oz. but I can't say for sure.

2. A fluid oz is the volume of one oz of water.

1. one jigger = 1 1/4 oz. The only liquid measurement I know. :-)

It is confusing. Liquid oz and weight oz. I basicly Hate metric because it was forced on us Canadians, but I must admit that at times it does make more sense. BUT I WILL NEVER ADMIT IT...:-)

8 Replies
1. re: margshep

One gallon of water weighs about 8 lbs (actually a little more--8.345 lbs) or about 128 oz. Each cup of water weighs almost exactly 8 oz or 1/2 lb. You can always measure both with weight with an accurate scale. As the amount of water decreases, the closer a fluid oz and weight oz vary. So if your looking at cups, pints and quarts--you're pretty close.

With metric, by definition, a gram of water is one cubic centimeter of water or 1 milliliter. Much easier since you know that a liter weighs 1 kilogram. I ain't no Canaydien, I just ain't stupid and payed me sum attenshion in math & sience classs.

1. re: hankstramm

Eye sea ewe tuk the saym creatif spelink coarse thit eye did. :-)

1. re: hankstramm

One gram of water does not measure one milliliter in volume. It's close enough (very very close indeed), but nowadays neither unit is defined with reference to water.

1. re: hankstramm

I run across confusions like this so often that I wonder if people are no longer familiar with the old saying, "A pint's a pound, the world around". It's not anal-retentively accurate but in most cases will "get 'er done"!

1. re: greygarious

Except that world around skips Britain, where a pint is 20 oz.!

1. re: greygarious

But a pint's about 1.25 pounds in the UK! (And I'm not talking about the price, sadly.)

http://en.wikipedia.org/wiki/United_S...

1. re: greygarious

Well, it works with water but not vegetable oil and that's where I was thrown when I was reading around.

1. re: chowser

cooking oil bottles are always marked in fl oz or liters. I suspect most, if not all, metric recipes use ml for oil.

We discussed the measurement of butter a while back. In the case of butter the usual measure is by weight, oz or g. Even when the quantify is given in tablespoons, it really means by weight. That is, you are expected to cut of x tablespoons as marked on the stick, not as measured with a spoon or measuring cup. If I recall correctly 8 tbls of butter, by markings, is close to 9 tbls by volume.

Even if oil is less dense than water, and you measure by weight when the recipe expects you to use volume (or v.v.), does being off by 1/9th ever matter?

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