Why is my soap too soft?


So, you’ve made a batch of soap, and it’s too soft. What do you do? If this has happened to you, don’t worry! An easy fix will help your bars harden up and be ready for use in no time.

Generally, the cause of too soft soap is using too many soft oils, the superfat percentage being too high, or using additives such as colorants or fragrances that unbalanced the recipe. And lastly, too much liquid. This can easily be avoided by using an online soap calculator and a wooden soap mold.

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It’s the most common misconception of all time that you just have to wait long enough for your soap cure, and then it should be hard. This might happen, but not always – especially with those who make their own cold process soaps!

Many people don’t know how different curing temperatures affect saponification rates (which leads us back to our original problem). They can even arise from something as simple as forgetting about them or moving around too much before noticing any issue at all, meaning these issues could’ve been happening unnoticed…

Why is my soap too soft?

Soap can soften for multiple reasons. This is common in almost any type of soap. However, this problem is much more prevalent in cold process soaps.

Cold process soap needs time in the mold before it can harden. Additionally, it also needs approximately four to six weeks to cure and get rid of the excess water. But even then, in some cases, your soap may still feel soft, so what do you do?

Well, unfortunately, there are many reasons why this might happen. But if you want to understand why your soap is too soft, the first step is to take a look at your ingredients.

  1. Soft oils

Some people like using soft oils like olive oil or canola oil to make soap. However, the more soft oils you use, the softer your soap will be. If this is the case, you most likely may have to wait a few extra days for it to harden before removing it from the mold.

  1. Superfat percentage

The superfat present in the soap can also be responsible for its softness. Sodium hydroxide is in charge of turning oils into soap, but not all of it saponifies. Most soaps possess a superfat content of around 1% to 7%. With that said, using additional oil can help produce gentler soap bars but at the cost of hardness.

A soap that has more than 7% of superfat is likely to feel too soft even after leaving it for a few weeks to harden.

  1. Additives

We all like to add more personality to our soap with colorants and fragrance oils. While they are not harmful, using too many additives contributes to increasing the superfat percentage. 

  1. Colorants

Suppose that your recipe already has 7% superfat, and you decide to add a considerable amount of color. This will likely result in a soap batch with excessive softness. Therefore, it is recommended to use less oil if you plan on adding more colorants.

  1. Fragrance oils

Fragrance oils also contribute to the soap’s softness. Using a balanced amount of fragrance oil in your recipe is essential. Otherwise, you may end up softening the soap or removing the scent from it. You can use an online calculator to help you determine the right level of fragrance oils for your specific recipe.

  1. Too much liquid

Another common reason people end up with mushy soap is that they’ve used too much water. As with other ingredients, it is essential to use just the right amount of water, depending on the recipe. Using too much-distilled water compared to the rest of the components will result in an extremely soft soap bar.

How do you fix soap that is too soft?

If you think that your soap is too soft, re-batching it will probably be your best option. Although it can be complicated for first-timers, it lets you reuse the ingredients making sure nothing is wasted.

Note: Before rebatching your soap, always determine the cause of the problem so you can avoid it in the future. 

How to prevent too soft soap

The good news is that ending up with a whole batch of soft soap can be easily avoided. By implementing the following:

  1. Hard oils 

Soft oils are good additions to soap, but it comes with the risk of softening the batch too much. Therefore, if you want your soap to have a consistent level of hardness along with longevity, using hard oils is the way to go.

It’s worth noting that your soap will harden quicker based on how much hard oil you’ve used. For instance, you might be able to unmold the soap the next day if you use 60% of hard oils in your recipe.

  1. Superfat/Lye Discount

Superfat and lye discounts mean the same thing. This term refers to the lye that did not saponify. On average, soaps have a lye discount level between 1 and 7%, with higher lye discount percentages resulting in a softer soap batch. We recommend keeping it at about 5% if you want a soap batch that’s structurally firm but gentle to the touch.

  1. Additives

As mentioned above, using additives like colorants and fragrance oils will contribute to the soap’s superfat percentage. Make sure to keep close track of not just which additives you are using but also the amounts you’ve put in.

  1. Colorants

We recommend using a 1:1 ratio per teaspoon of lightweight liquid oil for a balanced recipe. Sometimes, people want soaps with vibrant colors, which requires additional colorants. In this case, you can diminish the oil quantity in the dispersion.

  1. Fragrance oils

Bad batches often happen when people don’t measure the amount of fragrance they use by weight. If you don’t want your fragrance oils to mess up your soap batch, we recommend using a calculator to help you determine the right amounts to use depending on the ingredients you have at hand. 

  1. Water discount

Determining the optimal amount of liquid you should use in your recipe can be complicated. Calculators are helpful, but the key is to remember that it depends on how much soap you’re trying to make.

Reducing water in soap is not necessarily bad, though. It can help with the unmolding process. If you’re using other liquids like milk, you should maintain a balance between milk and water. 

  1. Molds

It’s essential to use a mold that easily allows air to flow to the soap. This will help the soap harden faster.

Plastic and silicone molds are known to slow the hardening process down, especially if it is cold process soap. These molds prevent the soap from coming into contact with air, thus extending its time to harden. We recommend using sodium lactate at a 1:1 ratio per pound of oils if you’re using these molds. It will help the soap harden faster and last longer.

Alternatively, wooden molds are good options that allow soaps to dry fast. These molds are excellent as they help the soap achieve the gel phase, thus speeding the hardening process up.

Can you put soap in the fridge to harden?

The answer to this question is more complicated than a simple yes or no. While putting your soap in the fridge helps it harden more quickly, it also makes the soap prone to condensation. This will eventually cause soap to sweat once it is ready to use.

If you’re having trouble with unmolding your soap from a silicone or plastic mold, you can try putting it in the fridge for about 15 to 20 minutes before trying again.

We don’t recommend putting your soap in the fridge even if you want it to harden as soon as possible. Doing so will prevent it from reaching the gel phase, which helps the soap become more firm. It’s still better to let it sit at room temperature.

What do you do if your soap doesn’t harden?

If your soap isn’t hardening, you can try making modifications to your recipe and rebatching it. However, remember that soapmaking involves a lot of patience. Try waiting for a few days and check again if it has hardened. If it still hasn’t, there might be something wrong with the recipe. However, rebatching will probably always be your best option in these cases.

How long does it take for soap to harden?

Several different factors dictate how long it will take for soap to harden. Typically, it is anywhere between 1 and 15 days. Some soaps are ready to use after just a few hours.

The main factor influencing how fast your soap will harden is the primary oil used in the recipe. If you want your soap to harden faster, try using hard oils instead of soft oils. Some great options include babassu oil or coconut oil if you wish for something more familiar.

How can I make soap harden faster?

I have an article where I go into detail on how to harden homemade soap much easier. However, here is the list version below:

1. Using A Water reduction

2. Adding Soy Wax or beeswax

3. Add Some Sodium lactate

4. Adjust your recipe to 40% hard oils

5. Adding salt 

7. Check your superfat 

8. Thicken the trace of your soap

9. Using an accelerating fragrance oil

10. Get a dehumidifier 

11. Using an electric fan

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