color variation

[jbluedun]

I fairly new to soap making and have lots to learn. I've been at it for seven years and enjoy it very much. I make it for my wife and myself, and to give as gifts. My question pertains to the color of the finished soap. I used to saponify using electric egg beaters, and it would generally take half an hour, give or take. I switched to using an immersion blender, and now it takes five to seven minutes. However, I've had an interesting contrast between two batches that used an identical recipe (goats milk soap with calendula petals from flowers we grow, pluck, and dry). I used the immersion blender for both. One batch came out considerably darker than the other, and I can't account for the discrepancy. Can anyone enlighten me? Thanks.
Jeffrey in Vermont

 

[earlene]

Hi, Jeffrey. Yes, the SB creates more friction, so it tends to move the batter from an unstable mix to emulsion to a very thick batter much faster than the old egg beaters or plain old hand stirring with a spoon does.

Are you doing HP (hot process) or CP (cold process) soap? How are the calendula petals added? On top of the soap only or as an oil infusion to color the soap yellow or orange, or in some other way?

Anyway, regarding the color discrepancy, I suspect it may be related to if the soap gelled or not. Soap that gels tends to intensify color more, although some soapers don't quite get a big difference in color intensity, but I think that is more related to what colorant is used, and I don't really recall if they used natural colorants or synthetic colorants.

In your case, do you know if one gelled an the other did not? If both are HP, then I suspect both gelled, in which case, the darker color would be for some other reason, such as one got hotter an 'burned' the goat's milk, thus darkening the soap as a result.

If both are CP, then it is quite possible one gelled and the other did not, which could explain difference in color intensity, particularly with a milk soap, but also with any colorant, including if you use the calendula as a colorant.

Another possibility is that the amount of calendula (if use as a colorant) used was different for the two batches. But you would know if you used more in one batch that in another, right? How do you prepare the calendula? Is it an oil infusion? Or other method?

 

[jbluedun]

Hi, Jeffrey. Yes, the SB creates more friction, so it tends to move the batter from an unstable mix to emulsion to a very thick batter much faster than the old egg beaters or plain old hand stirring with a spoon does.

Are you doing HP (hot process) or CP (cold process) soap? How are the calendula petals added? On top of the soap only or as an oil infusion to color the soap yellow or orange, or in some other way?

Anyway, regarding the color discrepancy, I suspect it may be related to if the soap gelled or not. Soap that gels tends to intensify color more, although some soapers don't quite get a big difference in color intensity, but I think that is more related to what colorant is used, and I don't really recall if they used natural colorants or synthetic colorants.

In your case, do you know if one gelled an the other did not? If both are HP, then I suspect both gelled, in which case, the darker color would be for some other reason, such as one got hotter an 'burned' the goat's milk, thus darkening the soap as a result.

If both are CP, then it is quite possible one gelled and the other did not, which could explain difference in color intensity, particularly with a milk soap, but also with any colorant, including if you use the calendula as a colorant.

Another possibility is that the amount of calendula (if use as a colorant) used was different for the two batches. But you would know if you used more in one batch that in another, right? How do you prepare the calendula? Is it an oil infusion? Or other method?

Many thanks, Earlene, for offering possibilities for the causes of the discrepancies. The soap is HP, and the calendula petals are added at light trace. I think you may have hit on the reason: I add the lye slowly to distilled water and slushy/semi-frozen goats milk. You are suggesting that the darkening could be due to the milk getting too hot in one batch, and I'll bet you are right. I've made this recipe four times or so, and just once did it darken perceptibly more than the other times. I'll make it again soon, more patiently. Thanks!

 

[earlene]

Cool! Good luck the next time.

Do you have goats? I know many people who have goats also make goat milk soap, simply because they have such an abundance of milk.

Others here use powdered goats milk, both for convenience and to avoid the darkening from mixing too hot. It's something to keep in mind if you ever want to give it a try. Adding the GM powder to the oils prior to mixing in the cooled lye solution seems to be a pretty common method when using the powder, rather than re-constituting the milk and making the solution that way.

 

[Zing]

I have absolutely nothing to add here, a hobbyist CP soap maker. Just wanted to say welcome to the forum!

 

[jbluedun]

Another couple of questions, Earlene, if you don't mind. The two local co--ops where I've bought goats milk in the past no longer carry it. I have two options as far as I can tell: buy some from a woman I know who keeps goats and sells the milk. I assume I'd have to pasteurize it before using it--do you agree? Or, I could buy powdered goats milk online. In that case, how would I reconstitute it so I'd be getting a 1:1 equivalence? Thanks!

 

[earlene]

I see no reason to pasteurize fresh milk going into soap. We don't expect or plan to eat soap, right? Pasteurization of milk is designed to remove certain organisms from the diet of humans who will be drinking that milk. Sodium hydroxide will certainly alter those same organisms during the process of soapmaking, so I would not be at all concerned with their surviving the soapmaking process with lye soap.

There are many studies that show that both the high pH of soap and the presence of lye (in the form of sodium hydroxide) render a huge number of organisms impotent. In fact there is one that addresses treating the hulls of ships with sodium hydroxide to prevent spreading invasive species from one body of water to another. (link) You can also do a bit of research on the organisms that pasteurization eliminates and then see what the effect of sodium hydroxide is on each of them and come to your own conclusions.

One is listeria, and by reading this article, I have no doubt it would not survive the process of making lye soap.


In regards to re-constituting powder GM, I don't bother. I simply use my lye solution as is and put the powder into the oils, mix well with my stick blender to make sure it is thoroughly incorporated, then add the lye solution as usual. If you prefer to reconstitute first, follow the directions on the package. I do not know if all Goat Milk powders are equal; I know that not all regular milk powders are equal in terms of how much the packages say to add to water.


Here is a video on the dry powder to oils method:



You will notice her rule of thumb is 1/8 cup of GM to 500 grams of oils. I use the same brand of GM powder as she shows in her video, so that is the amount I would also recommend, but as I said, I don't know if all GM powder would be the same for reconstitution purposes.

 

[TheGecko]

I assume I'd have to pasteurize it before using it--do you agree?

You don't have to since you're making soap with it. And even if you were consuming it, you wouldn't have to so long as it goes from the goat to the frig.

I grew up on a diary farm...every morning after Dad milked the cows, he'd bring up a gallon jar of milk to Mom and she'd put it in the frig and wait for the cream to rise so she could skim it off and we'd make butter or sometimes whip cream for dessert later on. Not only was it NOT pasteurized, it wasn't homogenized (emulsified) so there was always a bit of cream and you had to shake up the milk first.

NOTE HERE: Raw milk is safe to drink providing that it is stored correctly AND your animals are healthy to begin with. My Dad checked every cow thoroughly before milk and if he found any issues, he would milk the cow by hand because they still have to be milked, but he would toss the milk. He could have added the milk to the rest since it would be pasteurized and thus kill off anything bad, but if it wasn't milk he feed to us, then it wasn't milk he'd feed to anyone else's kids.

 

[jbluedun]

I thought of pasteurization only in that I wondered if rancidity would/could be an issue with raw milk. I've made cheese with raw GM, but never soap! If one goes to powder, do you just add extra water to make up for the fact that the liquid portion that goats milk provides is no longer there?

 

[earlene]

I thought of pasteurization only in that I wondered if rancidity would/could be an issue with raw milk. I've made cheese with raw GM, but never soap! If one goes to powder, do you just add extra water to make up for the fact that the liquid portion that goats milk provides is no longer there?

You still want the correct amount of liquid for your soap recipe, which is what you generally use, so yes. Make your lye solution with water (or whatever liquid you choose) as called for in your recipe. It's not extra water; it's the amount of liquid called for in the recipe. I suppose you are calling it 'extra' water because you already deducted the milk from the correct amount of liquid, but now you are simply adding it back in since you aren't using milk.

Do you get what I mean?


Pasteurization does prevent rancidity in milk, but it's primary purpose is to kill organisms that cause disease. See this link for more on pasteurization: Pasteurization - Wikipedia

However, I believe that sodium hydroxide + lipase in GM + the high pH of lye soap would not be an environment where rancidity from the milk would have an opportunity to occur. I cannot be certain, but it seems unlikely.

 

[penelopejane]

The liquid part of the “milk” is added as the water in the recipe to the sodium hydroxide. The powder is added to the oils (stick blend thoroughly before adding the sodium hydroxide to ensure it incorporates). Use enough GM powder to make the recipe water amount equivalent to milk according to the directions on the packet.

Sodium hydroxide will mix with an equal amount of water. If your GM doesn’t mix well with the oils you can divide the recipe water amount into two lots - one the same weight at the sodium hydroxide and the remainder to mix with the GM powder and other additives like salt.