what superfat % to use?

[Cactuslily]

As long as we are on the topic of SF...how do you calculate what % of SF would be appropriate?
Is there a formula for that? Sorry if this is a really newbie question.

 

[The Efficacious Gentleman]

As long as we are on the topic of SF...how do you calculate what % of SF would be appropriate?
Is there a formula for that? Sorry if this is a really newbie question.

I turned this post in to it's own thread rather than derail someone else's thread.

It will vary depending on the recipe and also from person to person. Can you expand on the question more?

 

[lionprincess00]

It's a personal preference for everyone.
Higher the coconut, higher the sf. Example is in salt bars with very high co. Some prefer co 25-30% with 5-8% sf...I can't do high co, so I choose below 20%. With it that low, I lower my sf to 3% give or take one point depending on what I'm in the mood for. Low co means less bubbly lather, so I lower it. Adding milks increases the sf, so I'll lower mine a percent.

Personally, I don't like 6-8% sf because it hinders my lather tremendously on my recipes.

Like I said, all personal preference and depends on what you soap with.

 

[shunt2011]

I agree that it's a personal preference made by trial and error. Most my soaps are between 7-9% and my salt bars are 20% SF. I do make a machinist scrub and a garden soap which I superfat 5%. So, you see it can vary from one recipe to another.

 

[Obsidian]

Yeap, lots of trial and error. I use 8% SF on every soap regardless of coconut amount. Even my castile has a 8% SF. The only exceptions are my salt bars with 20% SF and my shampoo bars with 3% SF. I'd say pick your favorite recipe, make small batches with different SF to see what you like best. A good place to start would be 3%, 5% and 8%. I really don't see any reason to go over 8-10% unless its a recipe with a lot of coconut.

 

[new12soap]

My only "rule" is that I would not go under 5% unless it is for a specialty recipe such as a laundry soap (or a shampoo bar as Obsidian said, but I don't make those).

The reason is because SAP values can vary so much, and that 5% will give you plenty of margin for your oils as well as for any slight measuring discrepancies.

It really is a matter of personal preference, but I also find that going higher than 5-6% impacts lather, except with all coconut oil.

 

[DeeAnna]

SoapCalc and Summerbeemeadow calc are both based on NaOH being 100% pure. Essential Depot and Lye Guy are supplying NaOH at 95% to 96% purity. This means the calcs build in a hidden superfat of 4% to 5% right off the top if you're using ED or Lye Guy lye. So when you choose your superfat to be, say, 5% in SoapCalc or SBM calc, the actual superfat built into your recipe is more like 9% or 10%.

I use my own soap calculator and it takes into account the actual purity of the NaOH I'm using, so there's no hidden superfat built in. I generally superfat around 3%. That means my recipes come much closer to the edge than most people's soap recipes ... and I still don't make lye heavy soaps.

If I made a high cleansing soap -- one with a lot of coconut oil or palm kernel oil -- I would probably raise the superfat just to keep the soap from being so harsh. But for my recipes with a balanced blend of CO, lard, castor, olive or high-oleic safflower, and such ... I don't think I need any higher superfat than what I'm using. I am making soaps that lather nicely, last a long time, and are mild to my skin.

As always, your mileage may vary -- as you can see, there are as many opinions on this topic as there are soapers!