Jazzed about Gel Phase

One of the many great aspects of soaping is the freedom to customize nearly every part of the recipe. From the colors to the design to the fragrance, there are endless variations! If you give 100 soapers the exact same 13 ingredients, you’ll end up with 100 completely different batches. It’s amazing how much artistry goes into soapmaking. Even after you’ve designed your recipe, chosen your colors and poured your soap into the mold, you’ve got another choice to make: to gel or not to gel?

‘Gelling’ and ‘gel phasing’ in cold process soap refers to a part of the saponification (soapmaking) process where the soap gets warm and gelatinous – up to 180 degrees. Gelling is extremely common in soapmaking, and chances are you’ve already encountered it. Gelled soap is more hard in the first weeks after pouring because it evaporates its water a bit faster than non-gelled soap. Gelled soap also has a more translucent, shiny look than non-gelled soap. None of these things affect the final outcome of the soap after a full cure, just how the soap looks. There is no final difference between gelled and non-gelled soap once the soap is fully cured — it’s purely an aesthetic quality of the soap.

Opinions about gel phase are as numerous as the colors of the rainbow, and some soapers actively choose to gel their soaps while others do not. Wondering what’s best for your soap? Read on!

The dark spots in the middle of the Moisturizing Avocado Bars indicate that partial gel phase occurred. Although these bars are fine to use, it just goes to show there is no half in/half out when it comes to gel phase. The bars may have looked better if they had gelled all the way or not at all.

Before we get into the ‘when’ of gel phase, let’s talk about the ‘how.’ The tips below are helpful if you have a strong preference on whether or not you want to achieve gel phase. If you don’t have a preference, your soap will be just fine if you let it sit, uncovered, after pouring.

If you want to gel your soap, after the soap is poured, place it on a heating pad on a low to medium heat for no more than 20 – 30 minutes. During that time, keep a close eye on the soap, checking it every 10 minutes or so. This is because if soap gets too hot all kinds of crazy things can happen, from volcanoing to heat tunneling to alien brains. Turn off the heating pad after 20 – 30 minutes but keep your soap on it. Keep it covered for at least 24 hours.

If you don’t want to gel your soap, soap colder (with your temperatures between 90 – 100 degrees F) and then place the soap in the freezer immediately after making it. You can also keep it uncovered and run a small fan over it.

When you might prefer gel phase

  • When coloring with Lab Colors: If you color soap with Lab Colors or any FD&C based colorant, you might prefer gel phase because it results in a more vibrant color. Take a look at the photo below:

The Soft Orange and Peach colored soaps in the middle gelled completely, while the soaps on the outer edge of the mold only gelled partially. Notice the difference in the colors — the portion of the soap that gelled is much brighter. For more on Lab Colors and gel phase, check out this blog post.

  • For more vibrant colors in general: Gel phase can brighten soaps made with other colors too, not just lab colors. The Psychedelic Spring soap was colored with micas, oxides and pigments, and much to our delighted surprise, gelled all the way through. Notice how the soap looks more translucent and ‘gel’-like:

When you might want to avoid gel phase

  • If you’re making goats milk soap: gel phase and milk soap are not friends. Milk soaps are best soaped cold (very cold), or else you risk scorching the milk proteins and sugars. That results in a brownish soap that doesn’t smell great! It can also result in a huge soapy mess, especially because milk soaps are already prone to getting too hot. For this reason, we do not recommend trying to achieve gel phase in goats milk soap — or any milk soap for that matter! Gelled milk soap is absolutely fine to use and there is nothing wrong with it but, it might not have the color you want.
  • Soap with fruit additives: Soap with fruit purees and additives, such as this Strawberries & Cream Soap, are generally best non gelled. It follows the same logic at milk soap: the sugars in fruit make the soap more prone to overheating to begin with, so adding extra heat to force the soap to gel isn’t the best idea! That being said, if you’re an experienced soapmaker you might want to try gelling fruit soaps, but in general we advise against it.

More examples of gel phase

Below is a soap we made for a fragrance test. It was freshly poured, but notice how you can already see the gel look forming in the center! This is also a good example of fragrances causing gel phase. Despite your best efforts, some fragrance will heat soap and cause gel phase.

This is the same soap 24 hours later. Notice the translucent color in the middle. It isn’t as opaque as non-gelled soaps.

So there you have it! Hopefully now you have a better understanding of gel phase, from what causes it, to what it looks like, to when you might want to achieve it. Do you have a preference when it comes to gelling your soap?

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34 Comments

  1. D.J. Binczik says

    I use small’ish individual shaped molds. 1/3 cup by volume. Would the same gel / not gel rules apply as they do when using a loaf mold? Or because of the size is gelling not possible? Or is it still possible with a heating pad? If using a heating pad would you still leave it on for 20-30 minutes?

    Sorry for the run-on question.

    Your assistance is appreciated.

    • D.J. Binczik says

      I want my soap to Gel

      How can I be guaranteed to get my soap into gel phase without heating pads?

      Every where I read says soap warmer- warmer is not a very specific temperature.

      • Kelsey says

        Hi D.J.!

        Gel phase can happen in any size mold as long as the soap gets hot enough. :)

        To help your soap go through gel phase, you can soap around 130 degrees F. Keep in mind your soap will start to set up a little faster.

        Also, if you don’t want to use heating pads, you can put a piece of cardboard over your mold and wrap it with a towel.

        -Kelsey with Bramble Berry

  2. Gen says

    Hi,
    Thanks for this great post. I am new to soap making & have read different things regarding what to do with your CP soap right after pouring it into the mold. This is the first time I see you can pop it in the freezer to totally avoid the gel phase. But I thought you had to keep it warm to further the saponification process.
    Thanks so much for your insight!

  3. Amber Bennett says

    I was told that gelling will affect your fragrances and keeping the soap cooler and not allowing it to gel will keep your fragrance stronger smelling and longer lasting in your bar. Reasoning being that since many fragrances have a lower flashpoint when your soap is heating up to gel it is actually burning off some of that fragrance.
    Has anyone else found that to be true? I don’t know because I never gel..I only make milk soaps.

    • says

      Hi Amber!

      I have heard this as well, but I have never actually noticed a huge difference in my soap that has been gelled, vs. soap that has not. If you want to be on the safe side, I would recommend adding a little more fragrance oil to the soap you plan on gelling :)

      -Amanda with Bramble Berry

  4. Shelley says

    Hello! Thanks for this information. I’ve been making goat milk soap for a while now, and I’ve achieved gel in some batches and soaped even colder and avoided gel in others. I actually like soaping at a pretty cool temp even when I plan for gel (90 degrees for oils and 75 degrees for lye/soap mixture), which I think avoids scorching the milk. I always use frozen milk and keep it in an ice bath when I add lye.(I’ve only scorched the milk once, at a higher temp, and I could really tell the difference.) But, then, after I combine the oils and pour the soap, I insulate the molds when I’m trying to gel, and I actually really like the way this turns out. It doesn’t smell bad at all (smells great while curing, even in first 24 hours). And the bars are harder and I like the appearance. Is this OK? Is it possible the milk is scorching after the soap is in the molds? I think if it were, it would smell funky. The cured soap still feels incredibly moisturizing and milky. Thanks for any advice!

    • says

      Hi Shelley!

      We have found that in general, when you scorch milk soap…you know it! Haha. That’s the great thing about soaping too, if you are happy with how your soap turns out, then I consider that a success! It sounds like your soap is just fine :) It also sounds like you have found a great technique for your milk soap!

      -Amanda with Bramble Berry

    • Patricia says

      I put my goat’s milk soap in the freezer for at least 24 hours before unmolding. And use very cold milk (almost frozen) to mix with the lye while making it. Lye will thaw the milk and it won’t get too hot to scorch it.

          • says

            Thank you, Amanda. I do freeze my goat milk before adding the lye. My question relates to my understanding of what Anne-Marie said, that “…Milk soaps are best soaped cold (very cold), or else you risk scorching the milk proteins and sugars…” Unless I’m mistaken, I believe she was referencing the temperatures of the lye/milk mixture and oil mixture when they are combined. So my question is, how cold, and is it possible to be too cold? Thanks!

          • says

            Hi Susan,
            For the oils, you can go as low as 75 – 80 degrees. If you’re using a coconut oil recipe it will probably start to set up at these temps, but thats okay! If you’re using olive oil, you can go even colder. The lye water should be around room temperature, so anywhere between 65 – 70 :)

  5. Ewelina says

    Hi,
    Thank you for this post. I have a question to gel or not to gel :) soap made with no milk, no purees, just water for lye solution but with sugar added for extra bubbles? What is the best approach here?

    • says

      Hi Ewelina!

      Good question! When you add sugar to the lye water, your soap will have the tendency to want to gel because of the extra sugars. If this is something you want to avoid, I would recommend soaping cold, and placing your soap in the fridge or freezer to avoid gelling. If you’d prefer your soap to gel, I would recommend insulating for just a few minutes, and once you can feel some heat coming from the soap, remove the insulation :)

      -Amanda with Bramble Berry

  6. Elizabeth says

    Great article! It’s really helpful to gather this info into one place, and it’s a great explanation of why or why not to encourage gel phase.

    I frequently use Lab Colors, so I usually encourage gel phase. But the first time I made goat milk soap, I didn’t realize that you have to be careful to avoid gel phase – I carefully controlled the temperature at the beginning, but I allowed my loaf to get too warm after pouring, and I ended up with a near volcano! I won’t make that mistake again!

    Another thing that can happen when you encourage gel phase is the presence of glycerin rivers, which I got when I encouraged gel phase with the Avocado Moisturizing bars. As y’all wrote a couple of weeks ago, the rivers don’t ruin your soap, but they add an interesting “leathery” appearance.

    • says

      Hi Elizabeth!

      Oh no! It usually only takes one soap volcano to avoid those exact methods again, haha :). Oh good point about the glycerin rivers! Thanks for bringing that up :)

      -Amanda with Bramble Berry

  7. Jaime says

    I have a question about your rebatch soap available for purchase. I know that you can’t really gel milk soaps successfully, so how does that work when using Brambleberry goat milk rebatch soap? Doesn’t that have to be heated (melted) to use it? How does that work with the goat milk? Just wondering.

    • says

      Hi Jaimie!

      Good question. That soap has already gone through the saponification process. When you make it for rebatch, you are melting it down with additional liquids. So while it does get hot, and you need to avoid burning the soap, it will not go through gel phase again. I hope this helps :)

      -Amanda with Bramble Berry

    • says

      Hi Dale!

      When making rebatch soap, your soap will not go through gel phase because it has already gone through the saponification process. With rebatching, you are just remelting the soap down. While doing this, it will get hot again, but won’t go through gel phase because it will immediately begin to cool once it is removed from the heat source :)

      -Amanda with Bramble Berry

      • Jerry Brown says

        Very nice explanation of gel phase. I thought however that a soap could still go thru a gell phase after saponification if the temperature & moisture content were above the Kraft tempt. Above this temperature at a specific moisture a liquid exists (gel) and below a mixture of liquid crystals, solid crystals,&/or water. Great explanation of this on this reference; Raut, Janhavi S.; Naik, Vijay M.; Siddhant, Singhal; Juvekar, Vinay A. Soap: The Polymorphic Genie of Hierarchically Structured Soft condensed-Matter Products; Ind. Eng. Chem. Res. 2008, 47, 6347

      • Jerry Brown says

        Very nice explanation of gel phase. I thought however that a soap could still go thru a gell phase after saponification if the temperature & moisture content were above the Kraft tempt. Above this temperature & at a specific moisture a liquid crystal exists (gel) and below a mixture of liquid crystals, solid crystals,&/or water. Great explanation of this on this reference; Raut, Janhavi S.; Naik, Vijay M.; Siddhant, Singhal; Juvekar, Vinay A. Soap: The Polymorphic Genie of Hierarchically Structured Soft condensed-Matter Products; Ind. Eng. Chem. Res. 2008, 47, 6347

  8. Sarah Balowski says

    I am a newbie when it comes to soaping but this knowledge will definitely be used for the next batch of soap that I make. :) I wish I would have know this before my last batch of soap as I would have preferred it to be gelled.

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