Hot Process and superfat

[luvtobeamom]

I use this calculation to get an accurate sf: http://curious-soapmaker.com/how-to-calculate-the-hot-process-superfat.html

I plug in on soapcalc my base oils with a 0% sf so I can get the lye amount needed for those oils to completely saponify. Then I use the equation in the link provided to get an exact sf %. If you like, you can post your soap recipe and I can tell you how much sf you need for it to be 5%

This makes my head spin:lolno:

 

[DeeAnna]

Don't worry about it. Pick a method that makes sense to you and ignore the others.

If you ever get to the point where you want to superfat with fancy stuff like lanolin or jojoba or other waxes, ask this question again and we'll talk about the more complicated methods.

 

[luvtobeamom]

Don't worry about it. Pick a method that makes sense to you and ignore the others.

If you ever get to the point where you want to superfat with fancy stuff like lanolin or jojoba or other waxes, ask this question again and we'll talk about the more complicated methods.

I will either superfat with cocoa, mango or shea butter. Will all of those be o.k. with the methods above?

 

[luvtobeamom]

This is how I would do this math:

Avocado Oil 2.70oz
Almond Oil 2.31oz
Cocoa butter 2.69 oz
Castor oil 1.93 oz
Olive oil 17.33oz
Coconut oil 9.63oz

Set it at 1% superfat for a buffer.

This gives you 5.36 oz of lye.

Then, take the total weight of your oils and multiply by .05

26.59 oz of oil * .05 = 1.33 oz of your super fat oil.

By the numbers you used, your superfat was:

1.93 / 26.59 * 100 = 7.25 %

Of course I am new to this - but my math makes sense to me. And I would do it in grams. I hate using oz for weight.

This does make sense to me, just wanted to make sure this would be o.k. to do.

 

[DeeAnna]

Yes, they'll be fine.

To give you some idea of a "reasonable saponification value" -- you'd be fine with a fat that has an NaOH sap value from 0.120 to 0.200, more or less. Your three butters have NaOH sap values from 0.125 to 0.135, so they're within that reasonable range.

The NaOH sap value for lanolin is 0.075 and for jojoba is 0.068. See the difference?

 

[Shirley Kates]

Obsidian has a valid point. The Gent has a valid point. The Curious Soapmaker has a point. Explaining the mathematical distinction between the three viewpoints will only be more confusing, so I'm not going to try.

In the end, any of these methods will work about the same, as long as you stick with a superfat that has a reasonable saponification value. There will be too much error when using superfatting with a fat that has an unusually low sap value, such as jojoba or lanolin. But you want cocoa butter, and that will work plenty fine.

The easiest and simplest is Obsidian's method. Calculate the recipe as a regular CP or HP recipe using the lye discount you want. Hold out the fat you want as superfat. Make the recipe with the rest of the fats and all of the lye as usual. At the end of the cook, the soap ~may~ possibly be a bit lye heavy. Small matter. Add in the superfat. If there is a bit of excess lye remaining, it will saponify happily with a bit of the superfat. The fat remaining in the soap will be the fat you want as superfat at the correct lye discount % you wanted.

 

[DeeAnna]

Hello, @Shirley Kates --

SMF discourages "necroposting" in old threads for various reasons. Instead we encourage people to start a new thread and perhaps give a link to an old post to give some background. In this case the original poster is no longer participating here so replies to her won't be read by the OP. That said, I am still around and willing to help. You quoted my post from 2015, but didn't add anything to it. What is your question or comment?

Also, we encourage new people to introduce themselves in the Introduction forum. Why don't you share a little bit about yourself there?