Scaling a Recipe Question

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karenricha

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:p Hello Soapers!!!

I am new...and for right now I want to stick with following soap recipes. My question:?: is I see some sites sell kits that make like 5 lbs of soap. Or I see some recipes that make 5 lbs of soap. I am waiting on my first silicone mold to arrive...but I think its like 2 or a 3 lb mold. How do I take a recipe thats out there that sounds great and scale it down to fit my mold size?:Kitten Love:

I sometimes get a little overwhelmed with all the terminology and wonder if I'll like soap making....but at the same time I love all natural soap - I purchase so much of it at craft fairs...that I said...I need to do this myself.

Its just expensive to mess up and not figure the right amounts...so I just want to make sure I do this right
thanks so much for your help and advice ~~ Karen
 
Hi Karen & welcome!

It's very easy to resize a batch using an online soap calculator. Personally, I like SoapCalc. When you choose your measurement (grams, ounces or pounds) you can also choose the weight of the oils you want to use. From there enter the oils and percentages and it'll give you the weight for each. At the top of the soap calc page there's a spot that says "SoapCalc Directions". Click on that and it'll help you get started. Here's the link and happy soaping!

http://soapcalc.net/calc/SoapCalcWP.asp
 
And using the site above, you can put in the actual recipe that you have as weights and then change it to the % option and adjust the total batch size down to what you want - the site will then tell you how much of each ingredient you need.
 
Theres also a thread in the cp forum that tells you how to calculate the amount of oils needed for a mould. I'd like to link to it but I dont know how to from my phone.
 
All good tips - I also think people should also know how to do this manually. Don't run away scared - it's very easy! I'll give a simple example:

Here's a 1# recipe for a straight Palm Oil soap:

1 lb Palm Oil
2.16 oz Lye
4.38 oz water

Now I think this would make a rock-hard bar of soap and be pretty underwhelming but it's just an easy example. The same process here will work for any level of complexity you like. So you have this for 1# and you want to make it for 3# ... how to scale? The class clowns are saying "just multiply it by three!" which is correct, but how do you know what to multiply it by if you want 15 oz? Here's how you do it:

What do I have? 1#
What do I want? 15 oz

We take what we want and divide it by the amount we are scaled for so it's:

Original / Target = Factor (I'll explain what factor is in a moment) or 15 oz / 1 lb = Factor.

If we remember from math class (I know, me either) we know we need to have similar scales on both sides so we just have to make both weights in the same "system". 1 lb is 16 oz so the first thing we do is 15 / 16 = 0.9375. There's a lot of different ways to look at this: We want 15/16ths of a batch is one way to do it. A fraction is always a representation of division so when we do the math we find out the answer is 0.9375 so let's call it 0.94.

0.94 is our "factor" and it is also a percentage. "Percent" means "per 100" and 0.94 is 94% - the batch we want to make is 94% of the size of the original. Not too hard so far right? We can easily see how this works in the first example I gave of scaling it to 3#:

3 lb / 1 lb = 3 (or 300%)

It works no matter if it's ounces, lbs, grams, doesn't matter.

So now that we have our factor, or we know what percent we need, we need to get 94% of every ingredient. The formula, if you want to call such a simple thing a formula, is:

Original X Factor = New Weight

We do this for each line item so our 15 oz scaled recipe is figured like this:

16 oz Palm Oil X .94 = 15.04 - rounding makes this not equal to exactly 15 oz but we can round this to 15.0 oz
2.16 oz Lye X .94 = 2.0304 or just 2.0 oz
4.38 oz water X .94 = 4.1172 or 4.1 oz

That's it - the new recipe is:

15.0 oz Palm Oil
2.0 oz Lye
4.1 oz Water

In this manner you can scale any recipe to any amount you desire.

Hope that helps make it less scary.
 
As for figuring how much will fit in your mold - Here's what I do.

An ounce of oil by weight is roughly an ounce of oil by volume. This is not close enough for calculating your recipe, but it's good enough for calculating how much a mold will hold.

You recipe will be (roughly) 1/3 water and 2/3 oil. So, if your mold holds 30 ounces, make a recipe that is 20 ounces of oil.
 
Lee, thank you for taking the time to write that all out. That was easy to understand even in my early morning, pre coffee mind.
 
many many thanks

Thanks everyone for all the great tips....
I am going to take this information and just try to calculate some stuff and see if what I am reading...is actually what I am understanding :)

It sounds pretty basic though :)

Karen
 

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