superfatting info needed

[Nite Hawk]

I know only a small amount concerning superfatting, and how it effects your finished soap.
It seems that some soap calulators don't recommend going above 8 persent superfat, while I read things in the forum where people superfat in the teens and 20s.
Does a high superfat make a softer or a milder soap? Can too much superfatting cause oils that don't join with the lye to go rancid??\
what are the pros and cons of high superfatting?
thanks for input..

 

[Hazel]

I read things in the forum where people superfat in the teens and 20s. Generally, a higher superfat or lye discount is used for soap with a high CO content to make the soap less drying. A higher percentage of oils which are more conditioning would reduce the need for a higher SF.

Does a high superfat make a softer or a milder soap? Yes

Can too much superfatting cause oils that don't join with the lye to go rancid??\ Yes.

what are the pros and cons of high superfatting?

The purpose of superfat or lye discount is to give some wiggle room to ensure your soap won't be lye heavy. SAP values are just averages of how much lye is needed to react to a specific oil for saponification. A higher superfat or a greater lye discount allows more free oils so there won't be excess lye, make the soap a little milder and for some oil to hopefully remain on the skin. (Soap is a rinse off product, after all. :wink Using a superfat also helps just in case scales aren't accurate. I check my scales by using 5 American quarters which will weigh 28 g//1 oz. I know this isn't as accurate as using calibration weights but at least it tells me the scales are still fairly accurate.

Too high of a superfat can decrease lather and there is a possibility of rancidity depending on the oils. There is a lower chance of rancidity if you use more stable oils (longer shelf life). FNWL has an article on storage tips and shelf life which you might find helpful. http://www.fromnaturewithlove.com/library/storagevegetableoils.asp

I vary the superfat/lye discount depending on what type of soap I'm making, certain oils and what liquid I'm using. Of course, I use a higher SF (18%-20%) for recipes with a high coconut percentage. My other recipes range from 5% - 8% depending on olive percentage, lard percentage, whether I'm using buttermilk or cream, whether it's a body bar or facial bar, etc.

HTH

 

[Nite Hawk]

So basically you wouldn't go higher than about 8% on a mixed oil or milk soap, and only go higher with the coco oil soaps?

 

[Hazel]

I probably wouldn't go higher but that's just what I prefer. There are members who have mentioned they use a higher SF. If I used 30+% coconut oil in a batch, I might go up to 10% since I find it a bit drying for my skin type. However, it would depend on the other oils. For example, I've found when I use lard I don't have to use a superfat towards the higher end. Lard doesn't have a real high conditioning value so I'm making an assumption that the lard combined with the other conditioning oils produces a synergistic effect. I really don't know for sure why this is but I have found out 5% SF is just fine for recipes in which I use lard.

There are people who use lower SF than 5%. You have to take into account the oils and the liquids. For example, someone making 100% olive oil/100% cream soap might want to use a low SF because of the extra fat content in cream. Also, soap does become milder over time. I had a salt bar batch which I messed up (it was my first and I was confused by the conflicting info). It was 95% CO and I only used a 13% SF. It was horribly drying so I stored it away. A year later, I decide I probably should use it because I hated the idea of wasting the supplies. I thought it would be all right for hand soap. I was quite surprised to find it much less drying although I still had to apply lotion. It's something you have to experiment with to see what is best for your skin.

I use 18%-20% SF for salt bars but other people may not need such a high SF. Different strokes for different folks! :wink:

 

[Nite Hawk]

So it appears one can vary the qualty and hard /softness of their soap by tinkering with the superfatting..
My milk cow just freshened, and if everything works out I would like to try to make a milk soap using milk instead of water with a mixture of OO, PKO,COCO, castor oil, was thinking of about a 7 % superfatting. Have concerns of the possiblity of it going rancid if it has too much oils / fats vs lye at that superfatting..
Any thoughts?

 

[Hazel]

So it appears one can vary the qualty and hard /softness of their soap by tinkering with the superfatting..

To a degree, using a higher SF in a batch with a lot saturated oils isn't going to effect the hardness by a lot and conversely, lowering the SF in a batch with a lot of unsaturated oils isn't going to make it a lot harder. A higher SF will help make soap a little milder.

What is the combined percentage of the PKO and CO? They have similar properties and too much can make the soap drying. The only oil I'd be concerned with the possibly of going rancid in your soap is the olive. However, it still shouldn't be an issue as long as it's not too old. I buy olive in bulk since I use so much of it and it takes me quite awhile to get through the container. I've never had a problem with DOS/rancidity except for in one bar. I had kept it to see how well the soap would hold up over time plus I didn't wrap it or keep it in a cool area. The bar was over a year old and it was only one tiny orange dot on it.

It's just my opinion but I think 7% SF for a cow milk soap will be fine since on the average the fat content isn't high.

 

[Nite Hawk]

did it go rancid because it was extra oil and didn't mix with the lye properly?
My cow is a jersey so has a higher butterfat in general, maybe around 5%

 

[Hazel]

The rancidity would be the result of unsaponified oil but I believe it was more of the result of the conditions of where I had it - unwrapped and left in an area with fluctuating temperatures and humidity (bathroom :wink. It actually wasn't even a full bar. I had cut 1/4 off the bar to leave out to see how the recipe held up over time.

5% isn't exceptionally high when you compare it to Nubian and some other types of goats. I've read goat milk butterfat content can range from 5% to 10%. Many soapmakers use milk from their own goats for 100% of the liquid amount. However, I don't know what SF they use so it's possible they use a lower one. It would be great if one of these members saw this post and could add to it.

Whipping cream has a much higher butterfat content 30+% and I normally use it for 1/4 of the liquid amount which would mean it would be like using 100% milk with approximately 7.5% butterfat. I use a 7% SF for recipes in which I add whipping cream and (knock on wood) I've never had DOS in any of the batches.

It's really hard to make specific statements about soapmaking since there are other factors (like environmental) which can effect batches. What works well for one person may not work for someone else. I can say "in my experience such and such happened" and someone else could have experienced the complete opposite. This is why we recommend experimenting with smaller batches and keeping control bars for a period of time to find out how they hold up over time.

 

[Nite Hawk]

Thanks for you input!

 

[Hazel]

You're welcome! I hoped I didn't confuse you. I don't know if you've already noticed but you'll see links to related topics if you scroll to the bottom of the page.

 

[brookings soap company]

So it appears one can vary the qualty and hard /softness of their soap by tinkering with the superfatting..
My milk cow just freshened, and if everything works out I would like to try to make a milk soap using milk instead of water with a mixture of OO, PKO,COCO, castor oil, was thinking of about a 7 % superfatting. Have concerns of the possiblity of it going rancid if it has too much oils / fats vs lye at that superfatting..
Any thoughts?

I think that 7% should work out great. I have been SF at 7-10 % for all my soap making and haven;t had any trouble with this for the 5 years I have been soaping.
The fresh milk from your own cow is neat. I use a lot of fresh foats milk, and although I do get it fresh from my friend, it would be neat to just go get it myself from my own goat