Calculating soap weight

[Silvergraylub]

Hi all!

I have begun my soap hobby recently and having bit of an issue calculating the soap weight.

Let's say if I need to fill 20 oz mold, i run the lye calculator so that the final weight is 20 oz (e.g. 15 oz oil and 5 oz lye water).

However when i actually mix them and weight the batter, i always get few oz less. Like 18.5 oz or so. I measured everything to the 2 decimals using a digital scale.

Is this common? Ho do i resolve this? As a result, im always short by few oz : (

I really appreciate any comments

Thank you!!!

 

[Vicki C]

Hi all!

I have begun my soap hobby recently and having bit of an issue calculating the soap weight.

Let's say if I need to fill 20 oz mold, i run the lye calculator so that the final weight is 20 oz (e.g. 15 oz oil and 5 oz lye water).

However when i actually mix them and weight the batter, i always get few oz less. Like 18.5 oz or so. I measured everything to the 2 decimals using a digital scale.

Is this common? Ho do i resolve this? As a result, im always short by few oz : (

I really appreciate any comments

Thank you!!!

Do you mean 1.85 ounces less? That is very weird. Are you taring the scale properly to account for the container? Probably yes just trying to think of possibilities. Some steam does get released with a little NaOH in the vapor but I doubt it would be two ounces worth. Hmm. Have you tried weighing the lye water before you mix?

 

[Ford]

Most molds reference oil weight. Verses total batch weight. Oils + lye/water. Are you confusing the two? Or did you not tare out your scale?? I've done both on several occasions.

 

[DeeAnna]

If you weigh every ingredient and your scale is working properly, the weight of soap batter has to be equal to the weights of ingredients in that batter. Matter doesn't mysteriously disappear as a normal thing.

So there has to be an error of thought or an error in weighing that's creeping in somewhere.

If you are measuring anything by volume, your weights will be off. One fluid ounce of soap batter does not measure one ounce by weight. NaOH and fat do not have the same specific gravity as water.

If your scale is not in calibration, or the batteries are low, or you're not taring correctly, that could also introduce errors.

Another thing is how you are measuring the mold. If you've measured the volume of the mold as 20 fluid ounces, the weight of the batter that's needed to fill that mold will not be 20 ounces by weight.

Please accept my apologies if it seems like I'm belaboring the obvious. Having helped others in the past, I have learned to cover all bases.