Grams vs. Ounces

[Vicki C]

Hi all. I have seen stated in so many places that “grams are more accurate than ounces.” Many YouTubers say it as a point of fact. Ounces are no less accurate. If you have a scale that only measures whole ounces, the units will be less PRECISE (not less accurate). But, I think most scales that measure grams or ounces will also measure at least to tenths of an ounce (my scale measures to hundredths.) My scale also measures to the nearest half gram.
Here is what I mean. Say I want to measure 10 ounces of something. (Not fluid ounces - Ug, I hate our stupid unit system with fluid ounces!) 10 ounces = 283.495 grams. My scale measures to .01 ounces, so I can measure 10.00 ounces - which is accurate within .28 grams. If I were to measure the same amount in grams, I would need to round up to 283.5 grams - and my measurement would be accurate within 0.5 grams. My scale will measure to a greater level of precision in ounces than it does in grams. The units are really no more or less accurate - it is the scale and the precision of the units that matter. If your scale only measured WHOLE ounces and WHOLE grams, than yes, it would be more precise to measure in grams.
All this being said… I use grams when making soap… because I just do. Although I track prices for everything I use in ounces. Because I just do.

 

[MelissaG]

Well I've lived under both the metric and the imperial systems. Ounces are far less accurate than grams no matter how good the scale is. It's far easier to make an error with ounces than it is grams because the ounces measurement may not change but the grams may be different. I use grams in everything I make except for soap now. It soap I find it doesn't matter as much but in everything else, it can make a difference. I honestly believe that it's time for the whole world to go metric. Canada uses an odd hybrid of the two and the US simply refuses to change. But that's my personal experience.

 

[dibbles]

My brain thinks first in ounces. If I know it takes 32 ounces of oils to fill my mold, I will start with that when using a lye calculator to make my recipe. The lye calculator will give measurements for everything in grams, ounces and pounds. I then use only the gram weight when making my soap. My scale only measures in whole grams, which for soap is fine. I do have a small jeweler's scale for more accurate measurements, but I don't do a lot of bath and body where I need to use it.

 

[paradisi]

No, grams are not more accurate. That's like saying base 8 math is less accurate than base 5. Or that minutes are an inaccurate measure of time because your dollar store timer rings before the one on the microwave. It's not the minutes, it's the equipment.

Any weighing / measuring problem is the scale's precision (how finely it can weigh).

Cheap scales will be inaccurate in any system. Even expensive scales, if they are imprecise, will give inaccurate results, in any system.

A bathroom scale would be useless weighing diamonds and a jewellers' scale useless weighing hay bales.. which says nothing about carats or pounds.

If one has difficulty doing math, and is converting a recipe from weight to percentage, grams will be easier -- but not more accurate.

 

[DeeAnna]

People with some scientific (especially chemistry) training and maybe a smidge of statistics can appreciate your point, @Vicki C. But most people don't have that training, so the nuances are hard for many soap makers to appreciate.

My bottom line: As long as a person is using a scale that has a precision appropriate for soap making, it doesn't really matter whether they want to see ounces or grams in the display. So I try to find out whether they're using a decent scale and leave it at that.

 

[Vicki C]

People with some scientific (especially chemistry) training and maybe a smidge of statistics can appreciate your point, @Vicki C. But most people don't have that training, so the nuances are hard for many soap makers to appreciate.

My bottom line: As long as a person is using a scale that has a precision appropriate for soap making, it doesn't really matter whether they want to see ounces or grams in the display. So I try to find out whether they're using a decent scale and leave it at that.

Yes - I agree, and I don’t know why I’m stomping my foot about it - I just get weary of accomplished soap makers on YouTube stating that “grams are more accurate.” You hear it ALL the TIME. I think it is confusing for beginners and reinforces this erroneous logic. And tbh I think I’m sensitized to the gender disparity in soapmaking, there seem to be many more women on YouTube, and I want the women soap makers to step up explain this correctly. I get discouraged when I hear women say they aren’t good at math - I think maybe they haven’t had a chance to get good at it as children and have been told they aren’t good at it and it’s a terrible cycle. It’s not even math really.
And yes - I used to teach math and chemistry. A long time ago.
Okay end of rant.

 

[AliensrReal]

I use ounces because my scale is more precise in ounces than grams. I do have a smaller scale that is very precise in grams and ounces, but you can only put so much on it as it is like a jewelry scale.

Also, I choose not to math well.

 

[DeeAnna]

Engineer here with lots of chemistry and math background. I totally get your frustration, @Vicki C. That said, I've also learned to pick my battles.

The "grams are better than ounces" myth will probably never go away, but I honestly don't think anyone is going to be harmed by it -- it won't materially affect the quality of people's soap nor the safety and effectiveness of their soap making. IMO, I think it's better to work to kill other soap making myths -- ones that really can cause problems.

As for me, I know changing the display on my usual soap making scale from ounces to grams doesn't matter. If I want more precision in my measurements, I change the scale I'm using to one with higher precision.

 

[Vicki C]

Yes, you’re right @DeeAnna. I would love to hear what myths you do think should be debunked! And fwiw I have nowhere near the chemistry knowledge you have.

 

[AliOop]

My top myth that I'd like to see debunked is using vinegar to "neutralize" lye burns. I believed that myself until I joined this forum - and I'd been soaping for years at that point. I feel so thankful that I never had occasion to use the vinegar on my skin, only to clean up counters and floors.

After that one, it's probably a tie between the myth that HP bars don't need curing, and the false belief that M&P soaps aren't made with lye.

 

[Kcryss]

Speaking for myself, I like to use grams with soap and body products, not because it's supposed to be more accurate or precise, but because I hate trying to do fractions of an ounce in my head ... or anywhere else for that matter. Grams are easier, at least for me.

 

[DeeAnna]

I feel like the one change that I've helped to make to soap making culture is to encourage people to stop using water as % of oils in general and specifically the old default of 38% water as % of oils.

I feel good to see more and more screenshots of recipes that (yay!!!!) are set to 33% lye concentration or 2:1 water:lye ratio.

 

[DeeAnna]

And with that change, I'm glad the unfounded advice that "a water discount is only for experienced soap makers" seems to also be dying a quiet death.

 

[Kcryss]

I feel like the one change that I've helped to make to soap making culture is to encourage people to stop using water as % of oils in general and specifically the old default of 38% water as % of oils.

I feel good to see more and more screenshots of recipes that (yay!!!!) are set to 33% lye concentration or 2:1 water:lye ratio.

I think you're being modest @DeeAnna , you have changed what a lot of people think about so many things I probably couldn't list them all.

The biggest one being that HP doesn't need to cure.

Your thoughtful sharing of all things soapy on the soapy stuff site has been an inspiration to likely hundreds of people. Dare I say even thousands? It has been your willingness and kindness in sharing your knowledge that has given people like me the ability to understand soapmaking at its core and the tools to develop our own recipes with confidence.

Thank you for sharing and making the soapy world a lot bubblier.

 

[Vicki C]

I think you're being modest @DeeAnna , you have changed what a lot of people think about so many things I probably couldn't list them all.

The biggest one being that HP doesn't need to cure.

Your thoughtful sharing of all things soapy on the soapy stuff site has been an inspiration to likely hundreds of people. Dare I say even thousands? It has been your willingness and kindness in sharing your knowledge that has given people like me the ability to understand soapmaking at its core and the tools to develop our own recipes with confidence.

Thank you for sharing and making the soapy world a lot bubblier.

I agree. The Classic Bells soapy stuff sees a LOT of visits from me. Very appreciative.

 

[Vicki C]

Speaking for myself, I like to use grams with soap and body products, not because it's supposed to be more accurate or precise, but because I hate trying to do fractions of an ounce in my head ... or anywhere else for that matter. Grams are easier, at least for me.

Oh I agree - my current scale measures to hundredths of an ounce but I had a scale that read in fractions of an ounce, like 4 3/8, which was downright annoying. I guess it was for cooking?
Now I have just gotten used to grams and that’s what I use.

 

[Shelley D]

Just sharing my experience about grams v ounces: even though I am born and raised in the US and have only used we call the Standard units of measure I'm accustomed to ounces but use grams in soap making, but for a slightly different definition of accuracy than just reading the scale. If I over pour in grams, it's a smaller discrepancy than when I'm measuring in ounces so in my head, grams are more accurate than ounces for this reason.
I have had recipes I measured in ounces come out with a lot more extra batter after I fill my loaf molds and it made me start to wonder if my over pours of oil were throwing off my lye calculations so I switched to grams and noticed less issues with recipes.
I have no idea if my thinking was correct, as I also made other changes, but it just feels better to measure in grams for soap making for me.

 

[VikingChick]

I also would love to see the US switch to the metric system. It just makes more sense to scale things by 10, 100, 100, 1/1000, etc. than by 16, or 4, or 5,280. I’d also love to universally adopt military time, but that’s another discussion.

Re: accuracy vs. precision, I think a lot of people don’t recognize that they’re not the same thing.

 

[Mobjack Bay]

Re: accuracy vs. precision, I think a lot of people don’t recognize that they’re not the same thing.

Yes, this, and measurements can be very precise, but not accurate if the scale is not calibrated.

 

[AliensrReal]

In the past the US has considered switching but you’re talking about completely overhauling the infrastructure which would be several billion dollars.

Honestly, I like having both imperial and grams. It allows me to learn how to switch my brain to whichever measurement is needed.