Which Oil or Fat Provides the Best Longevity for Soap?

If you’re into soap making or just trying to find the best bang for your buck, you might be wondering which oil or fat gives soap the greatest longevity. In our decades of experience, we’ve learned a few things that we’d like to share with you addressing this very question.

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So, Which Oil Gives Soap the Best Longevity?

If you’re new to the soap-making process in general, fat is a requirement. As a general rule, the denser the oil, the longer the soap will last.

Any oil or fat that is hard at room temperature is ideal when it comes to making soap. Here are a few examples;

  • Coconut Oil
  • Shea Butter
  • Palm Oil
  • Tallow
  • Lard

Of course, we don’t use all of these oils to make our soaps here. We steer clear of any animal products (e.g. tallow), but you could easily use these to make a soap that lasts an incredibly long time!

soap fats

What Oils Are Not Good for A Soap’s Lifespan?

Any ‘soft oils’ are not good for soap if you want them to last a long time.

For example, consider Castille soap or soap made primarily with olive oil. They’re typically very soft or in some cases liquid and don’t last nearly as long as a heartier bar.

That being said, you can mix olive oil into a soap that is mainly made from hard oil. This is perfectly fine to do. However, as a guideline, we recommend that at least 60% of the soap is made from a hard oil if you want it to last a decent amount of time.

What Happens if A Soap Is Too Soft?

A mild soap that is too soft is still going to give you a good clean. Don’t worry about that.

The main issue with a soap made from soft oils is that it is not going to do all that well in the heat from the shower. This means that when you end up using it, it will only further soften.

As I’m sure you guessed, soft soaps do not last all that long. Signs that soap might be too soft might include breaking apart in the shower or the soap losing its overall shape.

If you’ve already made a batch or purchased a bar that’s too soft, don’t worry. It’s not harmful and it still offers it should still clean quite well. Some people will find that using colder water is helpful along with drying it out properly.

Honestly, when it comes to having a bar of soap, there isn’t really any inherent advantage in it being from soft oils. You are just paying cash for something that you are going to need to be replacing sooner as opposed to later.

Does Soap Expire?

expiration date

All soaps eventually expire. Our soaps for example should last at least 2 years when kept in dry, cool storage conditions. Chances are that you will have used the soap a long time before that anyway.

Aside from the soap discoloring,  you can tell when a bar of soap has expired if it no longer lathers properly.

Can You Add Chemicals to A Soap to Increase the Lifespan?

Many commercial soap manufacturers will add chemicals to their soaps to increase their lifespan. This is why commercial soaps can last 2-3x longer than natural soap.

The problem is that these preservatives are foreign to the body and can cause problems. The most common problems when it comes to commercial soaps include;

  • Skin Dryness
  • Rashes
  • General Itchiness or Irritation

If you’re not familiar with our story, switching to natural cleansers was the turning point in my son’s nasty battle with eczema. Yes, preservatives can add time to the overall lifespan of the soap. But if you’re like us or suffering from any kind of skin ailments, switching to something made with all-natural ingredients can be a life-saver [1].

Wrapping Up

If you want a soap that lasts a long time, then you want one that has been made from natural, hard oils.

If you end up with an animal-based fat like tallow or lard, organic and what the animal ate does matter. All creatures store toxins in their fat as a protection mechanism.

Stick to these guidelines and we’re confident you’ll love your soap!


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5796020/

Mark Sanchez

Mark is a skilled soap maker with over a decade of experience in the craft. His passion for soap making began when his son developed eczema, and he discovered that using natural cleaning products was the only thing that helped. Since then, he has made it his mission to create high-quality soaps using only all-natural ingredients that are safe enough to eat. Mark is known for his attention to detail and commitment to creating products that not only clean but nourish and protect the skin. His soaps are sought after by customers who value natural, sustainable, and eco-friendly products.

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