A few questions after a lot of reading

[ngian]

Well I feel the need to ask a few questions that are not relative to each other, hoping to find some answers.

1) I've read that lye heavy CP soaps can become mild with a lot of curing. By "lye heavy" we mean that the lye which is discounted hasn't fully reacted with oils yet, or that we have initially used more lye that all the oils needed? And thus when we make a soap with excess lye, can we save this soap not only by rebatching (if we know exactly our error), but also letting it cure for a long time so as for the excess lye to react with CO2 in the air?

edit to add: Kevin Dunn did also an experiment: "A soap started out lye heavy when it was poured. After 24 hours, the soap was still lye heavy. However, after 11 weeks, the soap had a pH level very close to normal for soap. The pH was at a safe level. This happens because the CO2 reacts with the leftover lye to eat it up.". :eh:

2) I've read that "higher amount of liquid in a CP recipe does cause higher heat during gel."
Depending on the initial temperature of mixture I thought that it was the opposite that was true. I thought that using lower water amount (discount water) there will be higher temperatures in the mixture during saponification and thus in gel if the soap would gel and right after the starting of gel the temp would start to drop. Which one is true?

3) I found a great article that shows a table with saturated | unsaturated values of fatty acids that soapcalc gives us in a recipe's properties and recommends a specific range of lye concentration that can be used "safely". I know that there are many other factors that could possibly leads us to change the lye concentration (additives that accelerate, change the time to trace on purpose ect) but I think it is a good point to start designing a new recipe. Is this information worth depending on it?

4) In Kevin's Dunn lecture (HsmgMilkSilk2014.pdf) I've read in page 90:

"What is the saponification value of goat’s milk? It consumes 4% to 6% of the lye in a typical soap. If you use goat’s milk instead of water, you don’t need to discount your lye further."

Does this mean that we can make a recipe with a 0% lye discount in soapcalc and if we use goat milk instead of water we will have a final 4-6% SuperFat as milk will react with lye?

Thank you in advance for any answers you give.

Nikoshttp://www.soapmakingforum.com//www.pinterest.com/pin/create/extension/

 

[DeeAnna]

1. In this context, lye heavy means more lye that is consumed by the fats. A long cure is one solution to removing a small to moderate lye excess. For example, Dunn's experiments were for normal soap recipes with up to 5% lye excess. Larger lye excesses will not necessarily cure out if you've used an otherwise normal soap recipe. Carolyn (cmzaha) did a normal soap recipe with a very large lye excess (don't remember the exact %, but it was in the range of -20% to -40% lye excess). This soap stayed lye heavy after months of curing.

2. I'm pretty sure you missed the nuances. It isn't that low-water soaps necessarily stay cooler or get hotter than high-water soaps, all other things being equal. It's about the specific temperature at which a particular soap goes into a gel phase. A high-water soap will go into a gel phase at a lower temperature, so high-water soaps are more likely to gel than low-water soaps. Again, all other things being equal.

3. Robert's theory of lye concentration jives with my perspective and the advice I've given elsewhere on SMF. He has gone further than I have and proposed actual numbers rather than just given generic suggestions. If you want hard numbers to guide you, his table certainly is a good source to consult.

4. I think Dunn answers this question sufficiently and he also has resources to answer questions like this that typical handcrafted soap makers do not. You either need to trust him or not.

 

[HappyHomeSoapCo]

Great questions. Following.

 

[IrishLass]

Going off of personal experience, I can't answer question #1, but I trust what Dr. Dunn and Deeanna and Carolyn say about it.

In regard to question #2, I do have a bit of personal experience there to share. I've found my soaps with a lower amount of water to always need extra help to go through full-gel (except for my 100% CO soaps, that is- those will go through full gel just by looking at them askance, lol). Anyway, other than my 100% CO batches, I soap my other low-water batches on the warmer side of things (between 110F/43C to 120F/49C), and I stick them in a pre-warmed, 120F /49C oven, which I then turn off as soon as my soap is placed inside. This gives me full/complete gel 99% of the time. I'm reluctant to say 100% because there's always that odd 1% batch that pops up every once in a blue moon just to snicker at me. lol

In regards to question #4, I also have personal experience to share. When I make my 100% milk soaps (salt soaps excepted*), I found that lowering my superfat/lye discount level down to 3% (from 5%) gives me a soap that I like better. In other words, when I soap them at a 5% superfat/lye discount, the extra fat from the milk is extensive enough to cut into my bubbly lather quotient too much for my linking (I really love my bubbles!). Through experimentation, I found that a 3% superfat/lye discount for my 100% milk soaps was my 'sweet spot' for retaining the level of bubblage I like, while at the same time retaining the oomphy creaminess from the milk (all without any lye-heaviness).

*I use 100% milk in my salt soaps, too, but I superfat those different because I use 100% CO in them. For those, my sweet spot is a 13% superfat/lye discount.


IrishLass

 

[DeeAnna]

Dunn is saying that the lye reacts with the sugar (lactose) in milk in addition to its fat. This means the increase in superfat in a milk-based soap is greater than you'd expect by just allowing for the fat content in the milk. Since there's no way for a typical handcrafted soap maker to measure this, we have to trust to Dunn's findings. Good stuff....

 

[kumudini]

Dunn is saying that the lye reacts with the sugar (lactose) in milk in addition to its fat. This means the increase in superfat in a milk-based soap is greater than you'd expect by just allowing for the fat content in the milk. Since there's no way for a typical handcrafted soap maker to measure this, we have to trust to Dunn's findings. Good stuff....

I have always wondered how sugars increase the bubbles in a soap. is this a chemical resulting from the lye and sugar reaction then? and if some lye is used up by the sugar does it mean that the SF increases in a given soap recipe? If so, how do we account for sugar in a recipe?

 

[DeeAnna]

Bear in mind there are reducing sugars, such as lactose, glucose, maltose, and fructose, and non-reducing sugars, such as sucrose. The reducing sugars do react with lye. They release carbon monoxide and can add a brownish color to the soap. Non-reducing sugars react very little if at all with lye and do not change the color of soap.

If you use table sugar or molasses or maple syrup in your soap, you are adding mostly non-reducing sugar (sucrose). If you add milk (lactose) or honey (fructose and glucose) or fruit (fructose and glucose), you are adding reducing sugars.

How do you account for the lye consumed by reducing sugars? The short answer is to repeat Dunn's experiments. I don't know of any other option, to be honest.

Sugar like many other additives appears to increase lather by disrupting the crystalline structure of soap. It basically works by making the soap softer and more soluble in water. If you add a whole lot of table sugar to a lye soap, you will end up with a rubbery, soft, sweaty, partially transparent soap that may not lather well. The take-away lesson is that there's a happy medium to find.

 

[not_ally]

IL and DeeAnna, have been thinking about using milks/cream in CP so these posts were really interesting. I am Ok w/relatively high SF amounts b/c my skin is so dry, but I did want to try to stick w/my normal levels (7-8%), and it is kind of hard to estimate when you are using a fat adding liquid.

So lots to think about. Especially w/this: "Dunn is saying that the lye reacts with the sugar (lactose) in milk in addition to its fat. This means the increase in superfat in a milk-based soap is greater than you'd expect by just allowing for the fat content in the milk"

More soap, to make, darn it Just managed to give a bunch of it away. Need more curing space.

 

[ngian]

What a great thread this is, a whole new soapy information is in the air! I feel the need to take a good swig of a refreshing drink, and continue this cosy talking in our friendly bubbly spot...

1. In this context, lye heavy means more lye that is consumed by the fats. A long cure is one solution to removing a small to moderate lye excess. For example, Dunn's experiments were for normal soap recipes with up to 5% lye excess. Larger lye excesses will not necessarily cure out if you've used an otherwise normal soap recipe. Carolyn (cmzaha) did a normal soap recipe with a very large lye excess (don't remember the exact %, but it was in the range of -20% to -40% lye excess). This soap stayed lye heavy after months of curing.

Thank you for clarifying the exact percentages so as to have a greater understanding of how lye behaves within time...

2. I'm pretty sure you missed the nuances. It isn't that low-water soaps necessarily stay cooler or get hotter than high-water soaps, all other things being equal. It's about the specific temperature at which a particular soap goes into a gel phase. A high-water soap will go into a gel phase at a lower temperature, so high-water soaps are more likely to gel than low-water soaps. Again, all other things being equal.

Yes, now I remembered this when I had read it before making my first soap, but I somehow forgot it and confused it with other info on the way till now.

IrishLass your experience with low water soaps and suggestion of little CPOP to help with gel, is maybe happening more in colder days than usual (winter)?

3. Robert's theory of lye concentration jives with my perspective and the advice I've given elsewhere on SMF. He has gone further than I have and proposed actual numbers rather than just given generic suggestions. If you want hard numbers to guide you, his table certainly is a good source to consult.

Thank you for your suggestion. When I started reading the soap section in his site, I felt somehow familiar with his point of view, as if I was reading you. I have pinterest his site, great information found there!

There should be somehow a sticky thread or a library section that will have all the fundamental information in one place about soaping chemistry that it is being discussed and scattered all around the SMF.

4. I think Dunn answers this question sufficiently and he also has resources to answer questions like this that typical handcrafted soap makers do not. You either need to trust him or not.

Dunn and any other chemist that is doing scientific experiments with precise metering is the first one I'm going to trust. I'm more with the rationalism point of view needing evidence coming from maths and chemistry and lesser than evidence through experience. As a result of my lack in good perception of English language, I didn't understand the phrase

"If you use goat’s milk instead of water, you don’t need to discount your lye further."

and somehow I wrongly received the meaning of "further" as "further of the basic lye discount we all normally use". But after a second reading (as goat milk gives a basic lye discount already) and IrishLass' post, all were cleared out in my mind.

When I make my 100% milk soaps (salt soaps excepted*), I found that lowering my superfat/lye discount level down to 3% (from 5%) gives me a soap that I like better. In other words, when I soap them at a 5% superfat/lye discount, the extra fat from the milk is extensive enough to cut into my bubbly lather quotient too much for my linking (I really love my bubbles!). Through experimentation, I found that a 3% superfat/lye discount for my 100% milk soaps was my 'sweet spot' for retaining the level of bubblage I like, while at the same time retaining the oomphy creaminess from the milk (all without any lye-heaviness).

Bear in mind there are reducing sugars, such as lactose, glucose, maltose, and fructose, and non-reducing sugars, such as sucrose. The reducing sugars do react with lye. They release carbon monoxide and can add a brownish color to the soap. Non-reducing sugars react very little if at all with lye and do not change the color of soap.

I can also observe this phenomenon at Lather Lovers Swap 2012 were when milk, yogurt or honey was used, there was a visible cut down on lather as lye probably had more discount as it was partly used by milk fat and/or reducing sugars and more free oils means less lather as we know.

I guess the same goes with milk kefir as it has lactic acid that kefir grains produces from lactose and thus creating sodium lactate, a hardener and bubbles agent.

Does this also apply for the powdered versions of milk/honey/yogurt, meaning if powders also contains reducing sugars or are they acting more like table sugar?

Another question also arises but I think a lab experiment can answer that: what LYE prefers to attack first? Girls from oils or girls from sugars?

If you use table sugar or molasses or maple syrup in your soap, you are adding mostly non-reducing sugar (sucrose). If you add milk (lactose) or honey (fructose and glucose) or fruit (fructose and glucose), you are adding reducing sugars.

Sugar like many other additives appears to increase lather by disrupting the crystalline structure of soap. It basically works by making the soap softer and more soluble in water. If you add a whole lot of table sugar to a lye soap, you will end up with a rubbery, soft, sweaty, partially transparent soap that may not lather well. The take-away lesson is that there's a happy medium to find.

So with sugar we enhance the bubbles of the bubbly oils, but we somehow drop the hardness and long-lasting numbers of the bar soap?

There are many questions out there... the journey is endless... I must stop thinking and start making a soap after a month with no CP soap in production.

 

[DeeAnna]

" [Dunn said] 'If you use goat’s milk instead of water, you don’t need to discount your lye further....' "
"...and somehow I wrongly received the meaning of "further" as "further of the basic lye discount we all normally use". But after a second reading (as goat milk gives a basic lye discount already) and IrishLass' post, all were cleared out in my mind...."

Ah, my bad -- I didn't pick up on that. Nikos, you express yourself so fluently in English, I forget it's not your native language. I'm glad Irish Lass and I were able to clarify this for you.

"... Does this also apply for the powdered versions of milk/honey/yogurt, meaning if powders also contains reducing sugars or are they acting more like table sugar?..."

Powdered honey will contain glucose and fructose and powdered milk will still contain lactose. The drying process doesn't change that. Dried milk does not usually contain fat, however, at least that is how it's made in the US. In this case, only the lactose in the dried milk would consume lye, because there is no milk fat.

Yogurt, whether dried or fresh, has some of the lactose converted to lactic acid. We know lactic acid does consume some lye when it is converted to sodium (or potassium) lactate. I don't know if the amount of lye consumed by lactose is about the same as that consumed by lactic acid -- I haven't taken the time to look at the numbers.

"...Another question also arises but I think a lab experiment can answer that: what LYE prefers to attack first? Girls from oils or girls from sugars? ..."

<laughing!> That's pretty funny!

If I had to guess -- and it is a guess -- I would say lye will prefer the sugars, since it reacts directly with each sugar molecule. Lye has to cleave (break apart) the fatty acids from the fat molecules first, before it can react with the fatty acids.

Sugars are more like girls who come to a party by themselves. They're more approachable because they aren't surrounded by their girl friends. Fats are like girls who come to a party in a group. They're harder to get to know.

But there are a LOT of girls available from fat and only a few from sugar, so there will still be a lot of soap making going on. :shock:

"...So with sugar we enhance the bubbles of the bubbly oils, but we somehow drop the hardness and long-lasting numbers of the bar soap?..."

Yes, although the loss of hardness and long lasting is minor if you add sugar in small amounts. I think most people add 1 tsp to 1 tablespoon per pound (500 g) of oils and are happy with how the soap turns out, so sugar in those amounts does not seem to be a problem.

 

[reinbeau]

Very interesting thread, gotta digest it a bit