Lowest superfat?

Soapmaking Forum - Soap & Candle Forums

Help Support Soapmaking Forum - Soap & Candle Forums:

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
What is the lowest superfat % you would be comfortable with, for a soap that won’t be used for showering?

I am making a decorative large soap, and I am thinking of using only a 2% superfat to keep DOS at bay, also using ROE and EDTA. Any advice? I am not sure if this would affect trace, my recipe already traces fast anyway.
 

The_Phoenix

Well-Known Member
Joined
Aug 10, 2020
Messages
593
Reaction score
2,027
Location
California
I went on a 2% sf spree a few weeks ago. Was shocked that it made a noticeable difference in cleanup ease. My soaping containers and tools weren’t as oily didn’t leave a residue in my sink. I haven’t used them in the shower yet.

My main purpose was that the soaps unmolded more easily from the PVC pipes I used for the lollipop swirl challenge. I do think 2% was effective but I want to bump it up to 3% and test those. I do disperse my micas in oil so it’s likely not a true 2% sf. Which makes me think my sf was more like a 7% sf when I was calculating for 5%.
 

Tara_H

Mad scientist
Supporting Member
Joined
Jun 11, 2019
Messages
896
Reaction score
2,623
Location
Ireland
I'm really curious to hear more opinions on this, since the most recent reading I've been doing (of course I don't have links to hand) lead me to believe that the most important factor in the quality of the soap in terms of gentleness etc, is the profile of the oils used. Then the superfat is something of a hedge against imperfections in the recipe, inaccuracies in measuring, etc.
I'm imagining as being the ketchup element - it can enhance to a certain extent, but if what you're starting out with is amazing then it doesn't need ketchup 🤪
I've moved all of my masterbatched lye into (HDPE) squeezy bottles so I can measure to 0.01g accuracy, once I'm happy that I can consistently get that level then I'm planning on doing some batches at 0% superfat (nominal, there will be still residual superfat due to impurities in the lye, safety margins in the saponification values etc.) and comparing them to the same recipe at 3 and 5% to see how they're different after curing.
 

KiwiMoose

Supporting Member
Joined
Nov 16, 2018
Messages
3,544
Reaction score
7,699
Location
Hamilton, New Zealand
What is the lowest superfat % you would be comfortable with, for a soap that won’t be used for showering?

I am making a decorative large soap, and I am thinking of using only a 2% superfat to keep DOS at bay, also using ROE and EDTA. Any advice? I am not sure if this would affect trace, my recipe already traces fast anyway.
Do you mean it will never be used at all? Then I'd consider 0 to 1% depending on the purity of your lye.
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
I went on a 2% sf spree a few weeks ago. Was shocked that it made a noticeable difference in cleanup ease. My soaping containers and tools weren’t as oily didn’t leave a residue in my sink. I haven’t used them in the shower yet.

My main purpose was that the soaps unmolded more easily from the PVC pipes I used for the lollipop swirl challenge. I do think 2% was effective but I want to bump it up to 3% and test those. I do disperse my micas in oil so it’s likely not a true 2% sf. Which makes me think my sf was more like a 7% sf when I was calculating for 5%.
That is very curious about the ease of cleansing, but it does make sense. I read recently that a low superfat does not make a soap harsh either, so it would be interesting to hear about your test results. Thank you for your feedback
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
Do you mean it will never be used at all? Then I'd consider 0 to 1% depending on the purity of your lye.
No, never to be used. This lady has never used any of my soaps (buys them and displays them only) and this one in particular I am 100% sure she never will. (It will be kind of a portrait/drawing like). I live in a humid area too. The percentage you suggest is what I had initially considered but was afraid bc of the variation of oils, it seems SAP values can vary from harvest to harvest slightly. But 1% might be safe. Thank you!
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
I have a slightly different opinion

a negative superfat will cure out over time

if the soap is decorative (art only, or for long term display) the superfat would be better in the negative
I had not thought about that, but definitely worth considering it, thank you!
 

The Efficacious Gentleman

Lifetime Supporter
Joined
Nov 19, 2013
Messages
9,050
Reaction score
9,270
Location
Austria
Anyone who has made a salt bar or any other high CO soap will probably have a different view on the effect of the superfat! There we see a clear cause and effect - high superfat to counter the harsh soap.

Soap molecules bind to "dirt" but also to oils on our skin. More oil brought to the party in the soap itself (superfat) means that less oil will be removed from us, and less oil brought to the party by the soap itself means more oil will be removed from us.

It's why people often make a more cleansing bar (mechanics or gardeners soap for example) higher in co than a normal body bar but without a higher superfat or even less than they would normally use
 

Mobjack Bay

Lifetime Supporter
Joined
Apr 19, 2019
Messages
3,151
Reaction score
6,267
Location
Virginia
I routinely use 2-3% for the calculation in my recipes and have done so almost since the beginning. My actual SF is more like 3-4% after I add colorants in additional oil. Without a direct comparison of the same recipe made with SF at two levels, I can’t say how my working time is affected, but I typically have plenty of time to swirl unless the fragrance accelerates. A real positive is that I don’t get any soap scum in the showers or sinks even though we have hard water. I still get DOS very occasionally, but only when the soap has been exposed to bright sunlight for an extended period of time (my house has a lot of windows and gets a lot of sun). I recently tested soap made at 5% SF by another maker and didn’t notice a difference in hand feel.

Here’s the info I have on lye purity for different suppliers.
Lye Guy 99%+
Duda Diesel 99%+
Essential Depot 96% minimum, but typical batch is 98-99.9%
Ace Hardware (as I recall, it’s 96%. I often have to fish out impurities, so wouldn’t be surprised if it’s lower than that)
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
I routinely use 2-3% for the calculation in my recipes and have done so almost since the beginning. My actual SF is more like 3-4% after I add colorants in additional oil. Without a direct comparison of the same recipe made with SF at two levels, I can’t say how my working time is affected, but I typically have plenty of time to swirl unless the fragrance accelerates. A real positive is that I don’t get any soap scum in the showers or sinks even though we have hard water. I still get DOS very occasionally, but only when the soap has been exposed to bright sunlight for an extended period of time (my house has a lot of windows and gets a lot of sun). I recently tested soap made at 5% SF by another maker and didn’t notice a difference in hand feel.

Here’s the info I have on lye purity for different suppliers.
Lye Guy 99%+
Duda Diesel 99%+
Essential Depot 96% minimum, but typical batch is 98-99.9%
Ace Hardware (as I recall, it’s 96%. I often have to fish out impurities, so wouldn’t be surprised if it’s lower than that)
That is really good to learn about no soap scum, I also have hard water so this will be something I will try with my regular soaps. And thank you for the lye purity info, I have lye from Essential depot at the moment.
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
Anyone who has made a salt bar or any other high CO soap will probably have a different view on the effect of the superfat! There we see a clear cause and effect - high superfat to counter the harsh soap.

Soap molecules bind to "dirt" but also to oils on our skin. More oil brought to the party in the soap itself (superfat) means that less oil will be removed from us, and less oil brought to the party by the soap itself means more oil will be removed from us.

It's why people often make a more cleansing bar (mechanics or gardeners soap for example) higher in co than a normal body bar but without a higher superfat or even less than they would normally use
Agreed. This soap won’t be used on the skin though, but those are good points for anyone else who might have a high cleansing recipe or single oil (Coconut) recipe. Thank you.
 

Zing

Well-Known Member
Joined
Apr 5, 2018
Messages
1,442
Reaction score
3,905
Location
Minnesota
I have no advice, just here to rant a bit. I think I shared here how I recently visited my beloved sister's house after the long pandemic separation. She was so excited to show me her new decoration where she displayed almost every bar I've given her on an antique washboard. ???!!! I barely recognized one of my early bars because it was nearly 100% rancid. I promptly removed it from her decoration and tossed it. So I would say negative to low superfat for a decoration.
My normal sf is 3%, by the way.
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
I have no advice, just here to rant a bit. I think I shared here how I recently visited my beloved sister's house after the long pandemic separation. She was so excited to show me her new decoration where she displayed almost every bar I've given her on an antique washboard. ???!!! I barely recognized one of my early bars because it was nearly 100% rancid. I promptly removed it from her decoration and tossed it. So I would say negative to low superfat for a decoration.
My normal sf is 3%, by the way.
I felt the same way when she proudly showed me her display! In the bathroom by the tub in a copper tray to make it worse! Granted it is large room, but the humidity! There was one bar (probably the oldest) that I didn’t recognize because it had gone all yellow as well. thanks!
 

The_Phoenix

Well-Known Member
Joined
Aug 10, 2020
Messages
593
Reaction score
2,027
Location
California
That is very curious about the ease of cleansing, but it does make sense. I read recently that a low superfat does not make a soap harsh either, so it would be interesting to hear about your test results. Thank you for your feedback
I also want to see how much a difference the 2% sf will affect building lather. If “free fats” impede in developing lather, then a lower sf should allow lather to build more easily. I want to at 0% eventually and see what that does to the soap.

Lower sf makes for a less soft batch, which allows for cutting sooner, which makes for cleaner cutting.

From an economical standpoint, if 5% sf and 2% or even 0% sf doesn’t make for a lesser bar of soap, think of the savings in raw ingredients. That extra 5% sf adds up. The big question is how it will affect bubbly lather. I expect is will have a positive effect.

I tend to wonder if a very low sf would rid Castile soap of his sliminess.
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
I also want to see how much a difference the 2% sf will affect building lather. If “free fats” impede in developing lather, then a lower sf should allow lather to build more easily. I want to at 0% eventually and see what that does to the soap.

Lower sf makes for a less soft batch, which allows for cutting sooner, which makes for cleaner cutting.

From an economical standpoint, if 5% sf and 2% or even 0% sf doesn’t make for a lesser bar of soap, think of the savings in raw ingredients. That extra 5% sf adds up. The big question is how it will affect bubbly lather. I expect is will have a positive effect.

I tend to wonder if a very low sf would rid Castile soap of his sliminess.
I should expect to have a positive effect on bubbles as well.
In a different, but perhaps related point, for the made from scratch transparent soap (melt and pour like), the recipes call for 0% superfat as well, but they aren’t stripping because the glycerine being a humectant compensates for it. Cold process soap also creates glycerine naturally so that should help as well.
 

Obsidian

Well-Known Member
Joined
Jun 18, 2013
Messages
10,355
Reaction score
8,229
Location
Idaho, USA
I'd also go with a negative sf, say -3%. It will cure out so the soap won't be caustic and could help the longevity of the soap.
I have a bar that is over 30 years old, pretty sure it was made with a negative. Its still perfectly good, horrible to use but no dos or stale smell.
 

glendam

Supporting Member
Joined
Oct 30, 2018
Messages
402
Reaction score
798
Location
77063
I'd also go with a negative sf, say -3%. It will cure out so the soap won't be caustic and could help the longevity of the soap.
I have a bar that is over 30 years old, pretty sure it was made with a negative. Its still perfectly good, horrible to use but no dos or stale smell.
That is very interesting, 30 years old!
 

Latest posts

Top