Rebatching for additives?

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New Member
May 6, 2023
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Hi everyone, I am pretty new to the soapmaking world but have a few dozen successful batches under my belt.

I am wondering a few things about rebatching. Mainly, making my own simple base soap with no scents or colors and then just adding them during rebatching. I see most people use rebatching for fixing errors with a batch, but I am thinking more along the lines of customizing or adding to the overall quality through rebatching.

1. Is there any benefit to overall scent strength and longevity by adding all essential oils to a batch during a rebatching process vs during the CP saponification part? From what I have learned so far, many essential oils are changed or degraded during the saponification stage and I was wondering if leaving them out until the soaping process is complete and then adding them in during a rebatch would help them smell stronger and last longer?

2. Does anyone use rebatching to add in specialty oils so they don't get eaten up during saponification? I was thinking of making a low superfat base batch, (like 1-2% superfat) and then adding in luxury additives like Vit E oil, Neem oil, Shea, Jojoba, or others. I know that adding a smaller amount (less than 5-10%) of these oils before saponification doesn't change the overall finished product much, but I was thinking that being able to add them after the soaping process is complete may be more beneficial.

I know this would add another whole step to the process but if it adds even a small benefit to the end product I think it would be worth it.

Has anyone experimented with rebatching for these specific reasons and have any insights to share before I start experimenting?


Well-Known Member
Feb 20, 2013
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I gather you're wanting make the soap, let it saponify, then later rebatch the soap to add other ingredients?

If so, I think there are a few people probably do this, but not many. I certainly don't see this concept discussed here very often. Most folks rebatch soap instead to fix problems.

Rebatching to add ingredients is not an efficient use of energy nor of the soap maker's time. You're making the soap, letting it solidify, then shredding and melting and molding the soap yet again.

If you sell and have the clientele who will pay the additional costs of rebatching, I suppose you could justify doing this. For most people, however, soap making is often a marginally profitable business even without rebatching.

If you're making soap as a hobby, I think it's safe to say that most people try rebatching a few times and then develop a hearty dislike of the process. It would extinguish all the joy I get out of soap making if I was required to rebatch every batch of soap I make.

It's also true that rebatching -- reheating and melting soap -- tends to reduce the shelf life of soap. The longer soap is heated, the more likely the soap is going to oxidize and go rancid quicker.

If you want to add fragrance, fancy oils, or other ingredients to soap after saponification, then make hot process soap and add these ingredients at the end of the cook. Many people do use less fragrance in HP soap than in cold process soap.


There is good reason to think the fats added after the cook (hot process method) may remain more or less intact for some time, but there is also a high probability they don't remain intact forever due to the chemically flexible nature of fats and soap molecules in an alkaline, water-based environment. Superfat | Soapy Stuff

There is no research that shows fancy superfats do anything except add label appeal. Soap is typically on the skin for only a few seconds then it's rinsed off so there's not much time for exotic fats to do their magic. Also soap emulsifies fatty materials so they are water soluble. The very first fats that soap "sees" when it's used for bathing is the superfat not greasy skin dirt, so the superfat gets emulsified first and most completely. Most of the superfat in soap goes down the drain; it doesn't stay on the skin.

If you want exotic fats to benefit the skin, they're going to do a better job if used in a lotion that stays on the skin for considerably longer.
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Well-Known Member
Jul 22, 2019
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I pretty much have to second everything that @DeeAnna said.

Rebatching is a zero/negative profit enterprise. The majority of people who do it, do it as not to "waste" ingredients, but don't consider the labor costs of the process (which is normal). I would have to add $3.75 to the price of a rebatched soap just to cover my labor and energy costs. If I'm rebatching because of color or scent...scent alone will add another 50 to 75 cents a bar. There is no way I would be able to sell at that price in my market.

And labor costs are one of the reasons why I choose Cold Process over Hot Process. In the time it takes to make one batch of soap via HP, I can make six (or more) batches via CP.

Now let's consider what soap is. First, soap is a wash on/rinse off product. Depending on your bathing routine, soap may on be on your skin for a few minutes at best...not nearly enough time for you skin to gain any benefit. It why it is recommended to save luxury/expensive oils/butters for lotions, rubs, salves....stuff that is applied to the skin and left to be absorbed.

Second, what is the purpose of soap? To get you clean. And how does soap get you clean? By breaking down dirt and excess oils. And what is 'superfat'? Excess oil. So if the SuperFat isn't broken down by soap, it is rinsed away.

Carly B

Well-Known Member
Jul 18, 2019
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Making soap in the Forest House
I'm the outlier here. I make my own CP soap now, but for years I bought loaves of premade goatmilk soap from a goat farmer, then shredded it and made rebatch. I liked it much better than M&P back then--the M&P bases weren't nearly as nice as they are now. I still love my rebatch, only now I do it with trimmings from my own soap. By the time I get around to rebatching, I have a lot of different soaps, fragrances and colors, but most of the fragrance is gone, so I can add my own. And my own additives. And as much as I love my CP soap, my rebatch soap is what I choose both for my face and when my skin is feeling dry.

And why is that? Because I take my shreds, most of which have come from my GM soaps, and add some homemade oat milk or aloe juice, some emu or kukui or argan or other oils which I wouldn't put in CP because of the lye, and nuke it and then add whatever FO I want, and I have some of the nicest soap my skin has ever felt.

But, I make these for me---they are ugly, well, at least not pretty, and I only make one or two bars at a time. But I absolutely love them, and so does my skin. Having said that, If you're making them to sell, it's probably not worth it.

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