Weight of oil not same as container is labeled

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HappyHomeSoapCo

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I have noticed when ever I use the entire container of an oil/butter that if its a 32oz bottle and I pour it out into my bowl on a scale, then I am always short a few ounces. Or if its a 1lb tub of Shea butter, then it'll only be 13-14 oz. Why is this? I have even added the weight of the container and its still short!
 

galaxyMLP

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Also, you're not going to be able to get all of the oil/butter out of the container. I thought I was finished with my bag of Shea but I decided to really scrape the heck out of the bag even though I didn't think there was much left and I got an extra 2 oz out of it (originally 3 lbs). For my liquid oils, I try to leave them upside down when a little bit is left for the next time I soap. I us usually get another 1-2 oz or so out of a 6 lb container (101 fluid oz)

ETA: I can't read. Just saw that you weigh the container as well. It's got to be sold to you in fluid oz then. The density of most oils is less than the density of water which is usually taken to be 1. That means if you have 8 fl oz of water, it should weigh about 8 oz too. But, since the density of oil is less than water, if you have 8 fl oz of oil, it will weigh less than 8 oz (lower density means lower mass amount for the space, volume, it takes up).
 
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topofmurrayhill

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I have noticed when ever I use the entire container of an oil/butter that if its a 32oz bottle and I pour it out into my bowl on a scale, then I am always short a few ounces. Or if its a 1lb tub of Shea butter, then it'll only be 13-14 oz. Why is this? I have even added the weight of the container and its still short!
The weight of water in ounces and the volume of water in fluid ounces is pretty close, so you could fit 16 oz weight of water in a 16 fl oz bottle. Oil is less dense than water, so not much more than 14 1/2 oz weight would fit into the 16 oz bottle.
 

topofmurrayhill

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Yeah, but 2-3 ounces off on 1 lb of shea butter? That's not just crumbs left in the bag.
If maybe it's a 16 fluid oz tub, then it never contained 1 lb shea butter. At room temp, it could hold theoretically about 14.7 oz by weight of liquid oil. Solid fat, even less.
 

amd

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What is the accuracy of your scale? If you only go 1 decimal place out you may have an accumulated overage on prior uses and end up with a shortage on your final use.
 

HappyHomeSoapCo

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Thanks everyone. I think it must be industry standard to package by volume. I have noticed this with 2 different scales so thats not the case. I decided to call the company i ordered from and they said it was by volume. Although their label does say
"1 QUART / 32 OZ / 946 L"

I will call them back and suggest they put "fl oz" on the label
I too scrape and drain every last bit that i can!
 
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Obsidian

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I don't know any company that sells oils by weight. Most EO/FO are also by volume.
 

kchaystack

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Thanks everyone. I think it must be industry standard to package by volume. I have noticed this with 2 different scales so thats not the case. I decided to call the company i ordered from and they said it was by volume. Although their label does say
"1 QUART / 32 OZ / 946 L"

I will call them back and suggest they put "fl oz" on the label
Well quarts and liters are volume measurements - so I would have assumed the ounces were too.
 

topofmurrayhill

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I don't know any company that sells oils by weight. Most EO/FO are also by volume.
Soaper's Choice, Bramble Berry, Majestic Mountain Sage and others sell fixed oils by weight. That's the professional way to do it. Especially if you sell soap, you need to purchase and calculate the cost of your recipes by oil weight.
 

Steve85569

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Specific gravity of water is 1 at 68 F ( 15.6 C). A fluid ounce of water weighs ( has the mass of) an ounce at the same temperature. The specific gravity of CO is 0.925 at the same temperature. CO will weigh in at 92.5% by weight what the fluid ounces listed are. All oils and fats have slightly different specific gravities but none of them have the same mass as water.
Mass and weight are not the same but for our purposes they may as well be. That's another technical discussion though...

Clear as mud right?
Steve
 

HappyHomeSoapCo

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Well quarts and liters are volume measurements - so I would have assumed the ounces were too.
Ya, I should've realized that! Lol
Can't things just be more simple, sheesh. Now I'm going to go stare at SM3 for hours updating my purchases
 
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The Efficacious Gentleman

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Aye, so you have to find out the specific gravity to work out the weight. That should be on the MSDS. If not, it will be somewhere on the Internet.
 

cmzaha

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When I purchase from a company such as WSP that sells fragrances by fluid ounce I do not expect to get 16 oz by weight. Several I buy from state Net Wt 16 oz and I expect and get 16 oz by weight which I get. I called one well know company about the fact I was short on 3 1 lb containers of shea butter, when I was buying small amounts, and all 3 containers were short 2-3 oz. My containers stated 1 lb not 16 fl oz. Some companies sell by weight such as soapsupplies.net and some sell by fluid weight. Brambleberry seems to not like to put weight on their bottles so who knows, I do not purchase from them or very very seldom so I do not really worry about it. When I purchase 25#'s of shea I expect to get 25lbs which I do. Liquid oils in gallon bottles average 7 lbs per gallon.
 

Seawolfe

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Ya, i understand it all now. It's just so silly. Whats the point, or benefit of selling by volume anyways? Lol
Because the volume of a 16 fl oz container is the same no matter what the contents, but the weight will vary with the specific gravity of the ingredient. Its just easier - thats why most food recipes are in volumes.
 

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