Who's new
There is sometimes confusion about superfatting and lye
discounting when you are first starting out with soapmaking. They both mean
the same thing using less lye than needed to completely saponify (turn
into soap) the oils used but refer to it being done at different times in
the soapmaking process
Now, you may be wondering why you would want to use less
lye than needed? We want our soap to lather well, and weve all seen how
quickly the bubbles in the sink die when you put a really greasy pot in
there! Plus, isnt soap supposed to clean oil off of the skin?
There are a couple of reasons why we would do this.
First, no two batches of the same type of oil have the exact same SAP
(saponification value the amount of lye needed to turn that oil into
soap). Some lye calculators have slightly different values for oils. So, we
use less lye than needed to completely saponify the oils to allow for any
variation in SAP values between batches of oil. Second, that small amount of
oil left in the soap leaves a light emollient film on the skin, and is one
of the reasons why handmade soap is so much gentler and less drying than
store-bought soap .
So, the difference in the two methods is broken down as so:
We start with our soap formula:
For this formula, my trusty lye calculator tells me I need
138.6 grams of Lye. Ive decided that I want to use a 5% lye discount, so I
now only need to use 131.7 grams of lye.
Superfatting
Using the same soap formula as above:
My trusty lye calculator still tells me that I need 138.6
grams of lye. This time, Im going to add a 5% superfat. In this example,
Im going to add 46 grams of Cocoa Butter at trace.
So, the difference is that Lye Discounting means that
youve reduced the amount of lye that you use, while Superfatting means that
youve increased the amount of oils. Both methods achieve the same end
result, but just go about it different ways.
Which method you choose to use is entirely up to you. Some
people choose to superfat because they believe that by adding a luxury oil
or butter at trace, less of it will be saponified. Because the soap is still
caustic for a time after moulding, others believe that all oils and butters
in the mix will be equally saponified, and therefore choose to discount
their lye instead. Others are like me lazy! I would rather add all the
oils and butters at one time, as this means that Im less likely to forget
to add one if things start happening quickly, so I choose to discount my lye
rather than superfat.
You can do both, but be aware that this may cause you to
have soft soap that doesnt cure properly, and does have the potential to
increase your chances of your soap developing DOS (Dreaded Orange Spots) if
the unsaponified oil turns rancid.
Author: Becky,
Soapmakingforum member
Recent comments