Soap Making Molds: Is There a “Best” Soap Mold And Why?

Soap Making Molds:

We believe that one of the most important parts in cold process soap-making as you’re learning, is to understand the basics of the process. We don’t want to overwhelm you with every single type of soap making molds. This should not be your focus at this time. Your focus should be on the process. 

Understanding lye safety, soap recipes, gelling your soap, ingredients that have an impact on your soap, soaping environment/climate, colorants, IFRA guidelines and so on, are important things to learn. Then, you can turn your attention to ramping up your design and how you want the finished bar to look (round, square, embeds, textured etc.). 

Having said that, it is also a good idea to have a basic understanding of soap molds and how they to can play a role in the outcome of your soap product. Keep in mind the mold is what will dictate the size of each batch. After you’ve done this, your mind will start to go quite crazy about all the potential molds out there!

In this post we’ll discuss some basics of soap molds, as well as some inexpensive molds you can practice with until you understand the process of soap-making.

What Can a Mold Dictate in Soap-Making?

Final Appearance:

• Your mold can dictate, size, shape, even texture of your final bar of soap. 
• The mold itself, also dictates how big of a batch of oils, lye, water and other ingredients you’ll need. 
• Cure Time: The ability for the soap to go through gel is easier with certain molds!
• Ease of Clean-up. That’s right, some molds are easier to clean and/or prep then others

I. Popular Soap Making Molds & Ideas For Beginners:

* Please don’t oven-process any of these mold ideas to force gel. This is simply about learning the basic’s of cold process soap-making. 

Free Molds: Are you on a budget and someone who wants to learn the basics of cold process soap making? If so, a free mold (or reusable mold) is what you need!

A Milk Carton:

Probably the most popular free soap mold is a simple milk carton, mostly because everyone has it in there home already and it’s easy to use. The easiest size to use is a half gallon. You can simply cut the milk carton in half, (no need to line with wax/freezer paper), and pour in your soap batter when ready.

Once it cures, you can cut the side of the carton or tear it to release the “finished” soap. The squared-off look, makes it easy to cut into smaller bars. 

Tip: Don’t use any aluminum/metal material for your molds, as it reacts negatively with soap/lye.

A Pringles Container: 

Another easy and inexpensive soap container is a pringles container. Simply pop off the lid, (after you’ve cleaned it of course) and pour your batter in. These can produce really nice rounded soap bars. At the end of the cure, simply cut down the side of the container.

The great thing about this container and the milk carton is there’s usually no need to reinforce the sides or line the container. Oftentimes, it’s strong enough to support the weight of the soap batter. 

Yogurt Containers:

Nowadays, you can find tons of different shapes of yogurt containers. These make for awesome, inexpensive ways of creating individual bars of soap.

Rubbermaid Containers:

You can find Rubbermaid containers at the dollar store, and they hold up nicely when making cold process soap.

Deli Containers:

Reuse deli containers. Again, many of these come in different sizes and shapes, but they’re easy to clean and use as inexpensive ways of practicing your cold process soap making skills. Furthermore, you can just discard when done. 

Other types of recycled molds:

USPS boxes, shoe boxes, and liquor store boxes.

Keep in mind, you may have to line different boxes with freezer or wax paper so they don’t leak! 

Tip: If you need to line your molds, using things like freezer paper, wax paper, or a simple grocery bag works!

Tip: Lining your molds will help with sticking issues, and/or leaking issues with some materials.

II. You’ve Decided to Step Your Game Up…Here Are Some Molds To Try!

So you’ve sone some practicing. You’re ready to step it up a bit and try using more custom, long lasting and reusable molds.

Below we’ll go through some of the most common ones you can find for your soap making endeavors.

Silicone Molds:

Legit, one of the most popular choices among soap makers are silicone molds! Silicone molds can come in many different shapes, sizes, and designs. One of the most important things to look for with silicone molds is there strength and durability. You want to have a nice mixture of durability, but also flexibility.

Why? 

Well, soap batter is heavy, and if you use a flimsy silicone material it can actually distort the silicone or make the sides of the mold bulge out. You want flexibility, so you can easily manipulate the silicone to release the cured soap. 

Other “pluses” to silicone molds is that they are easy to clean (hot water and dish soap does the trick). Oftentimes, there is no need to line the molds. Longevity is another plus, along with giving your soap a glossy finish. 

One of the only drawbacks to silicone molds is they don’t insulate as well as say, wood. We usually force gel when using small silicone molds, but again it also depends on various other factors. For example, how you are insulating you soap, ingredients, lye concentration, etc. Keep in mind the soap may take longer to cure. Using additives like sodium lactate can offset this, or gelling your soap. 

Plastic Soap Molds:

What makes plastic molds great is that there is usually a wide variety of shapes, designs and sizes. So you can create really beautiful individual bars of soap. 

One of the biggest drawbacks, however, is there sustainability. Many more inexpensive plastic molds can break when trying to get your CP soap out. Oftentimes, there is an extra step involved, like spraying them with mineral oils to help the soap release easier as it helps create a barrier between the batter and the plastic mold. 

It’s also recommended to not use recipes with a large percentage of soft oils, as this can make it even more difficult to unmold from plastic molds, like castile soaps. 

In general, you will see plastic molds more suitable for melt and pour soaps. We don’t typically use plastic molds as we make all cold process soap at this time. In addition, it’s not a material to try and force gel though methods of heating, as the plastic can melt or become warped and your soap design ruined. 

Plastic molds may also be more prone to soda ash (due to the difficulty of getting through gel phase). In order to make large batches you may need multiple trays of the same mold. If not, you’ll be making small batches at a time, which can be very time consuming. 

Try performing a water discount in your soap recipe to help with soda ash issues.  

Wooden Soap Molds:

Probably our favorite type of mold, along with silicone. Wood is great for insulation, and creates very structurally sound looking bars. Wood is not going to warp. Often times with a water discount (and even without one) you don’t need to force gel, as the wood and amount of batter alone will do the trick. 

As always, covering your soap, and spraying with 99% isopropyl alcohol is always recommended to reduce soda ash. 

Talk to most soap makers that do this for a part-time hobby or even a full time soaper and they will probably tell you, the one draw back is the extra component of lining these molds. It doesn’t take a ton of time, but it is an extra step that can be tedious. The positive that comes with wooden molds is you can build or even buy large wooden molds, making upwards of 50-60 or more bars at a time. 

You will most likely need to line your wood mold(s) with wax or freezer paper, as these materials make unmolding and pulling your “batch of soap” out fairly easy (minus the weight, haha). You can also purchase silicone liners that sit inside the wood molds, which makes things fairly straight forward as well, but usually at an extra cost. 

Like silicone molds, wooden soap molds are also very durable. They can last a long time. If you’re handy or know someone who is, it is completely possible to make your own wooden soap molds, but there are also plenty of options out there if you’d rather purchase one. 

Final Thoughts!

Hopefully this is a good place to start as far as understanding some basic molds in soap making. There are certainly more materials out there, like PVC, and acrylic soap molds, however this should be more then enough for a starting point. 

Please, feel free to share any tutorials you may have at building your own mold, or other ideas you have found that work well for making cold process soap.

Thanks for stopping by, we hope you stop by again soon!