Calculating number of bars of soap

[orangetree71]

What is the formula to figure out how many 4 oz. bars of soap a recipe will make?

 

[MorpheusPA]

What is the formula to figure out how many 4 oz. bars of soap a recipe will make?

Theoretically, divide your pounds of oil by 4 to figure the number of 4 ounce bars (1 pound of oils = 4 bars).

In practice, not all of the water gets lost no matter how long you cure. Count on losing 10% of total weight or so to evaporation. It could be lower, higher, or right on.

So really, I'd use Oil Weight + Water Weight. Multiply that by 0.9, then divide the result by 4 for the number of bars.

Your mileage is going to vary depending on the humidity at which the bars are dried, drying time, air pressure, external weather, moon phase, and whether a black-footed squirrel leaps over the roof above your drying soap...

OK, the last two, no. But close.

 

[IanT]

lol that was a good little chuckle

 

[orangetree71]

Thank you!
Tamara

 

[Guest]

Very interesting!

Just what i was looking for, thank you!

Heres maybe a twist or just a dumb question. I just cant seem to wrap my head around this though and i think its because i use different water discounts depending on which soap im making...

how does this .9 calculation work when using... say... a 36% water ammt vs a 30% or less?

Heres why im wondering.. im working on a master spreadsheet that will hopefully do all of my calculations for me including individual bar cost. Im getting a little tired of redoing them for each different batch. So im trying to figure how many bars i will get out of each recipe based on the size of the batch and the size of the bars i will cut-in ounces.

So i was figuring i would add the total batch weight, then divide it by the ounce weight of each bar i was going to cut and end up with the number of bars and then i could have it calculate cost per bar.... then i started thinking about evaporation and my head started spinning! LOL

so, how do water discounts figure into this? flop!

 

[Kansas Farm Girl]

There is a spreadsheet on Kathy Miller's page already made up with all the SAP numbers and calculations for you. It gives you the number of 4 oz bars your batch will make. It uses macros and has many tabs and ranges locked down. I usually run my recipe through soapcal and this one too, I like to keep track of my batches so I know which one's I liked and which I didn't. I just copy the data out of this and paste special/values into another spreadsheet where I number my batches and keep notes.

http://millersoap.com/soapdesign.html

Why reinvent the wheel unless this one just doesn't do what you need.

 

[Guest]

calculating bars based on water discounts

Hi Kansas, thanks you for the link. I think i found the sheet you are talking about in there. I dont think that does it though. Her sheet looks like it calculates based on a fixed 13% water loss.

 

[majstor]

Water loss will always be relatively same no meter what the water discount.
Im doing calculator for weight and price of batch or individual soap. Its going like

((lye weight+water weight+EO weight+oil weight)-10%)/100g=number of bars

 

[Kansas Farm Girl]

I have never tested how much water loss between the time I cut bars to the time they are cured to see what the weight dif is. I should do that just to see. I try to cut my bars around 4 oz, but that is at about 24-48 hrs, not after cure. I do know they shrink as they cure.

 

[majstor]

I have never tested how much water loss between the time I cut bars to the time they are cured to see what the weight dif is. I should do that just to see.

I have done that and before saponification was 724g and after unmolding was 670g. Thats about 7.5% loss

 

[Guest]

Majstor, Do you know what your water % was for that batch?

 

[majstor]

Majstor, Do you know what your water % was for that batch?

It was rather low, 30%