Posted by on 3/12/2021 to Let's Talk Soaping
Gel Phase in Cold Process Soap Making: Let's Chat About it
Where to Begin?
We would be lying if we said understanding "gel phase" was just as easy if you've never experienced it before. Having working knowledge of the cold soap making process, makes many of these terms and lingo easier if you've experienced them before, even if you did not come out with your desired results.
Much of soap making is researching, learning, testing, trial and error. The more soap you make, the better you get at making it, and the more you understand why things went right and why they may not have went according to plan.
What is Gel Phase in Cold Process Soap Making?
Gel phase occurs after your lye solution has come in contact with your oil/butter mixture. Gel phase is part of the process where your soap is going through saponification, and may appear gelatinous.
What is occurring?
Simply put, your oils and lye solution is going through chemical reactions that will eventually leave no lye behind (ideally if your calculations are correct in a lye calculator), and you will be left with a different substance, that of soap!
As this process continues the soap begins to heat itself within the mold (even up to 200 degrees F, yikes!). Usually the changes begin on the inside or middle of the soap and extend outwards. As things heat up, the center will start to become a gel-like consistency and look darker then the surrounding soap.
Things like a water discount, molds, additives, fragrances used, and the environment can all influence gel phase and whether your soap gels completely, or goes through something called "partial gel".
We'll discuss partial gel momentarily.
Does all soap go through gel phase?
No. Some soapers actually prefer their soap not go through gel, as it doesn't effect the quality of the final bars!
What are the benefits of gel phase?
Probably the biggest benefit of gel is purely aesthetics. If you want bolder more vibrant colors, you probably want your soap to "gel" completely!
Gelling your soap leads to not just more vibrant colors, but can give it a sheen or shiny look to them. If you're using bright mica's or pigments the colors will be even more vibrant, if using natural colorants without gel, your colors may look somewhat dull in appearance.
Again, what is the purpose of the soap? What are your intentions? Personal preference comes into play here, and whom you may be selling them too?
The other BIG benefit of gelling your soap is being able to unmold the final product faster. Gelling your soaps can have you unmolding within 24 hours, instead of 48 or 72 hours later. This has to do with the elevated temperatures, which allow for the soap to harden more quickly.
What are the key Factors in Gel Phase?
Temperature! One of the more tried and true methods if you want the "gel phase" to occur is by soaping at higher temperatures. For instance, soaping when your lye and oils are around 130 degrees, and then insulating.
Please read our post on "How to Insulate Cold Process Soap"!
Even if you start with a higher temperature, you'll want to also keep in mind your environment. For instance, when we started, we watched one soap maker specifically who soaped in a large attic space in a colder climate. She would force gel by using a heating pad (15-30 minutes) + insulating with towels.
As always, be careful not to overheat your soap, as this can lead to other issues!
Why you may NOT want to gel your soap?
The biggest reason we may choose not to gel our soaps (which is rarely) is we are making milk based soaps, or soap high in sugar content, like beer, haha! These types of ingredients can scorch or burn with high temperatures.
Not only does this create a smell not wanted, but it can cause it to become undesirable aesthetically as well, leaving it discolored!
Soaps like these, we usually will start with our oils and lye solution at room temperature. For us that's around 70-80 degrees when we say "room temperature". If it's a cold climate outside you may even be able to get away with placing the soap mold in a garage or basement.
However, the best way we have found (if you don't want get to take place) is placing the mold in the refrigerator for 24-hours.
Keep in mind that if you don't force gel or you prevent it all-together, you most likely will have to wait additional time or until it is firm enough to unmold.
You can also leave your soap just resting at "room temperature" uncovered, but we've had a lot of issues with soda ash when doing this, and sometimes the soap will still go through partial gel.
So what is partial gel?
Partial gel is explaining a process in which the entire soap DOESN'T go through gel. Usually you'll find that the inner portion of the soap is darker then the outside.
If you remember we'd said that the soap tends to heat up in the inner portion first, where it is more insulated from the environment.
So you're left with an inner part of the soap being darker and more translucence, and the outer portion more of an opaque look to it, and (unless caught early) there is not much you can do at this point to change that.
If you catch it early, you can again try to force gel, using an oven process method. Basically, placing your soap in the oven (preset to 170-180 degrees F), and then turning off the oven, leaving your soap overnight, or for a few hours.
Keep in mind this is not full proof, especially if your soap has already begun to cool off. Experience working with soap pays off big time in these situations!
Remember, the colors also will look different if colorants were used, the inner colors may be more vibrant, and the the outer more of a dull look to them, especially if using natural colorants.
Related Article: Working with Colorants in Cold Process Soap Making: How to Premix
Partial gel happens do to uneven temperatures during saponification. It could be due to...
a. The temperature of the oils/lye solution when they were mixed!
b. The environmental temperature!
c. Poorly insulated soap once mixture is in the mold!
d. Soap beginning to cool off before gel phase reaches the edges!
e. Additives used (certain butters).
We love to gel our soaps! Being fans of bold, vibrant colors, we rarely leave our soaps un-gelled. However, this may not be for you!
Remember, when using ingredients high in sugar like milk, honey, & fruits, it may not be appropriate to gel your soaps. Sometimes whether you gel or not has to do with ingredients, sometimes it's based on personal preference. Un-gelled soaps are perfectly harmless as are partially gelled soaps!
Please share your favorite "gelling" successes and failures in the comments section of our blog! Thanks for stopping by!