Rebatching soap is a method of hand-milling, melting and molding new soap out of cold process waste.
It is also a fantastic way to use any soap scraps that you have lying around.
Let’s go ahead and take a look at the process. We will also some of the most frequently asked questions concerning rebatching.
Why Rebatch Soap?
There are several good reasons to rebatch soap. We will take a look at each, in turn. BTW – You will very likely immediately think of ways that you can turn scrap soap into quick profits.
Fixing a Bad Soap Batch
Most people experience rebatching for the first time out of necessity. They spent all of the money, time, and resources to make a batch of cold process soap. Then they find that it did not come out as expected. We can fix that!
- The most common reason for this is that the soap maker forgot to include something. This is often the scent or essential oil. Re-batching gives you to do-over. That is, a do-over, without sacrificing any of the quality that you work so hard to put into the original batch.
- The second most common reason that people rebatch is lye. This is usually because their lye calculations were not quite right when they made the initial batch. For example, the soap is “lye heavy”. This means there is still active lye after all of the fats and oils have saponified. If this happens, it is a simple matter to rebatch the soap and add the necessary fats or oils to allow for complete saponification.
- And third; some soapers feel that rebatching the soap makes a better bar. I have personally found that some rebatches create a milder bar, depending on how they are rebatched. However, most soap makers would prefer not to go through the effort of essentially making the same batch twice.
Eliminating Waste
Aside from fixing a bad batch, rebatching allows you to fully utilize soap scraps you have lying around. This is an excellent way to almost completely eliminate any waste. It’s also a great way to reap the benefits of all your hard work put into the initial batch.
As mentioned previously, some soapers prefer to rebatch immediately as part of their normal process because they believe it provides a better bar. It is interesting to note that many consumers are willing to pay a slightly higher price for soap that has been “hand-milled.” Hand milled is another way to say rebatched.
How to Rebatch
Rebatching is simple. It can be accomplished on a stovetop, in a microwave, or in a slow cooker such as a crockpot. Below is a video by Soaping 101 that does a great job of demonstrating the process. Below that are the steps that I personally use.
Here is how I Rebatch, step-by-step:
Rebatch Prep
- Start by taking your soap to be rebatched and breaking it down into tiny pieces. The easiest way I have found to do this is with a cheese grater. I grate the soap exactly like I am grating a block of cheese to put on a pizza. Those shavings are quick to melt and become our renewed soap.
- Next, place your shredded soap in whatever vessel you plan to use. For this example, I will use a crockpot. In my crockpot example, I will put the temperature at medium.
Heads’ Up! Rebatching soap can be done on very low heat (If you have a slow cooker with a setting above “keep warm” but below “low” on “Crockpots”). However, it will take a very long time to melt. Placing the slow cooker on high could result in burning the layers of soap that are in immediate contact with the inside of the pot. If your slow cooker only has keep-warm, low, and high, then low will be the most appropriate setting.
Starting the Melt
Our next step involves adding liquid to help re-melt the soap and make it more manageable for putting into a mold. Before you do this, however, be aware that if your soap was already heavily super-fatted, you might not need much if any additional liquid. If there is still a good deal of free oil (unsaponified oil), this can act as the fluid lubricant for making a smooth batch.
- Once the soap is in place, add about one ounce of water for every pound of soap. You may very well need to add additional liquid as the melting process continues. However, one ounce is a good starting point. Now, cover the crockpot to both retain the heat and capture any evaporating liquid.
Of course, if the reason for the rebatch is that you initially added too much water, you can use the same method but leave the cover off so that the majority of the water evaporates out. This can realistically take four weeks off of the hardening time (curing).
- To this point, we have not yet stirred the soap. Now it is time. If you have already, that is certainly okay. Following is the general guideline I use to determine when to stir for best results.
Mix it Up
When to Stir the Pot: If I have added 1 ounce of water per pound of soap, I generally let it sit in the crockpot for at least 30 minutes. Then I begin stirring. This is typically about when the bottom and sides have started melting to the point that mixing the batch will help more evenly distribute the heat.
The amount of time it takes for your soap to melt will depend on several factors including:
- How hard the soap was, to begin with (how much liquid remained)
- The level of heat you are applying
- The amount of shredded soap in the crockpot
- The size of the shreds or chunks of soap being melted
- How much fluid was added
- How frequently and thoroughly you are stirring the soap
The Final Step (in the pot)
- Once the soap has reached a consistently even melt, you are ready to add any ingredients you may have missed the first time around. You can tell because there will be a minimal number of non-melted pieces (if any), and the soap will have a consistency similar to the “gel phase” seen in hot process soap making.
Heads’ Up! It is crucial to note at this point that you should carefully measure the soap temperature before adding anything that might be averse to heat. An excellent example of this would be some essential oils and fragrances that tend to flash, which is to burn off under high heat conditions.
- If your soap has now been fully blended and is fluid enough for the mold you wish to use, it is time for the final step. Simply spoon your melted soap into the multiple-choice. A best practice for solid molds is to continually lift and tap the mold on a firm flat surface to ensure the soap is fully compressed.
A Word on Consistency: If you added a great deal of water during the process, your soap might very well be more liquid-like. In this case, it might have a consistency closer to cake batter than to the thick porridge-like batter that you would get from adding just one or two ounces of liquid per pound soap during the rebatch process. Keep this in mind to help you determine the desired pourability of your soap before it goes into the mold.
This is the entire process in a nutshell.
Second Chance Soap
I personally refer to rebatching as “second chance soap”. This is because it really is giving you a second opportunity to make your ideal soap. That said, take advantage of this opportunity and experiment. Instead of water, you might want to try cow milk, got milk, beer, or wine (with any carbonation and alcohol burned off).
You might also want to add a sorbitol solution, some sugared-water or honey. There’s so much you can do!
In short, there is a tremendous opportunity for not only saving a bad batch or eliminating waste but also to create something entirely new. And that new thing could very well become your next bestseller.
>>> Get The Inside Edge
There is another post on this site that provides a detailed cheat sheet chart and insider tips on making 2nd Chance Soap (rebatch). It can save you batches and batches of trial and error.
Marketing Magic
Before we close out, here is a quick note on how you might market your rebatch soap. Consider using the term “hand-milled.” This is what you are doing when you cut up or great the existing soap before rebatch. Milling is nothing more than breaking down a significant component into many tiny parts. This is done for the purpose of better working the material. Because you are not using a machine like so many large factories, you have earned the right to use the term “hand-milled.”
Although it may seem like a small thing to you, this can be a huge deal to the purchaser. The term handmade has become more and more common over the years. This is also true of handmade soap. Hand milled, on the other hand, will likely be new and exotic to many of your patrons.
Using this term is also an excellent way to remain fully transparent about the soap being purchased. As a consumer myself, I know that I certainly appreciate any relevant facts about an item I am about to purchase.
In Closing
I hope you found this information useful and have an opportunity to use it soon. As a final tip, I will simply suggest that you keep a scrap soap bin available where you can easily toss in any bad end-cuts, damaged bars, and the like.
It may take several weeks or even months to get enough for a sizable rebatch. However, you can also benefit from rebatching soap small amounts in a microwave in a matter of minutes. Below is a video by “The Ultimate Guide to Hot Process Soap” on just how to do that.
Happy soaping and selling!