Problem with mold sizing

I know how to do that part of it. What I'd like is a formula that actually takes into account the altered water amounts of various lye concentrations. This formula does not take that into account, and there are times it shorts my total batch size so much that my molds are not at all filled. But with lower lye concentration I can end up with more batter than will fit into a mold.

 

Ahhh, I see now.. I've had this happen too, so frustrating!

 

I've made a excel model which would allow me to resize my recipe to fit the multiple molds that I have.

 

Deleted as the previous user has gone away.

 

I've been following this and it has really grabbed me, so I did a little digging around and found this:
https://www.modernsoapmaking.com/how-to-resize-a-soap-recipe-for-your-soap-mold-imperial-and-metric/
I hope it's helpful for some of you, especially in the difference between imperial and metric (U.S. vs International) as well as volume vs weight.
On a side note it also has the formulas for column molds.

 

No

 

could you please explain exactly what is not working ?

 

Tested on a recipie of 70% palmoilen, 20% Coconut, 5% Castor & 5% Sheabutter with no super fat or fragnance. lye and water at the ratio of 1:2.

I gave a mold size of 1,000ml (10cm x 10cm x 10cm) it resized my batch to 1,007g of which 692g is oils, 206.5g water and 103.25g of NaOH. Which means the weight to volume conversion difference of less than 1%.

May I know the weight to volume conversion ratios (especially the increase in volume of lye solution when dissolved in water, in this case at a ratio of 1::2) used in deriving the result of 1,007g.

 

we are not doing weight to volume conversion here .. we use a well know approximate formula.
the formula assumes that
Amount of Oils in Grams = Mold Volume in ml * ( 0.65 or 0.75 ) .. we use a typical value here 0.69 .. this formula is tested and known to give accurate results
the idea we don't make volume to weight conversion based on ingredients density ( Specific gravity ) ..that the total volume of soap recipe after chemical reaction is not equal to the sum of volumes of its ingredients .
at some point when we have enough accurate data of soap recipes and their final density .. we can use the data to learn an artificial neural network to expect the final recipe density based on ingredients and their amounts ( Artificial intelligence ) .. until we get this point .. I think the current formula works well.

Thank you!

 

Strange ..... it's now working fine! Tried it a couple of times last night and it was giving wrong calculations. Tried loading an existing recipe and changing mold size, was still not working correctly.

 

Thanks. Point taken. density of the final product is not equal to w.a of densities of the ingredients, hence volume may differ.