Walk into any supermarket and you will find shelves full of products labelled as soap. Bar soap, liquid soap, shower gel, body wash. They all do roughly the same job — they clean your skin. But most of them are not actually soap in the traditional sense of the word. They are synthetic detergent bars, manufactured at scale using industrial processes and chemical surfactants that strip the skin far more aggressively than they need to.

Cold process soap is different. It is the oldest and most traditional method of making soap, and it produces a bar that is fundamentally better for your skin. At SOAPHERA, every bar we make is cold process. In this post we want to explain exactly what that means, why it matters, and what the real difference is between a cold process bar and the soap you might currently be using.

What Does Cold Process Actually Mean?

Cold process soap making is a method that combines oils and butters with a lye solution (sodium hydroxide mixed with water or milk) and allows the mixture to go through a natural chemical reaction called saponification. During saponification the oils transform into soap and glycerin.

The term cold process refers to the fact that no external heat is applied during the process. The reaction itself generates heat naturally, but the soap maker does not artificially heat the mixture to speed things up. This slower, more controlled process preserves the beneficial properties of the oils and butters used.

Once poured into moulds, cold process soap needs to cure for a minimum of four to six weeks before it is ready to use. This curing time allows excess water to evaporate and the bar to harden fully. A properly cured cold process bar will last longer in the shower, lather more richly, and be gentler on the skin than a bar that has not been given enough time to cure.

The Glycerin Question

Here is the part that most people do not know, and it is probably the most important reason to choose cold process soap over a commercial alternative.

When oils saponify during the soap making process, glycerin is produced naturally as a byproduct. Glycerin is a humectant, which means it draws moisture from the air into the skin. It is one of the most effective natural skin moisturisers that exists, and it is produced in every batch of soap made using the cold process method.

In commercial soap manufacturing, this glycerin is extracted and sold separately to be used in other cosmetic products like lotions and creams. The soap that remains after the glycerin has been removed is far less nourishing for the skin. It cleanses, yes. But it does not moisturise.

In cold process soap, all the glycerin stays in the bar. This is why people who switch from commercial soap to cold process soap almost always notice that their skin feels softer, less tight, and less dry after washing. The soap is doing two jobs at once — cleaning and moisturising — rather than just one.

Our Berry Muffin Soap Bar is a perfect example of a cold process bar that lets the glycerin do its work alongside nourishing olive oil and coconut oil. It is ideal for everyday use and suitable for all skin types including sensitive skin.

What Goes Into a Cold Process Bar

The quality of a cold process soap bar depends entirely on the quality of the oils and butters used to make it. Different oils bring different properties to the finished bar.

Coconut oil produces a hard bar with a rich, bubbly lather. Olive oil creates a conditioning, gentle bar that is particularly good for dry or sensitive skin. Shea butter adds deep moisturisation and a creamy, skin-softening quality. Castor oil helps the lather develop and supports the other oils in creating a well-rounded bar.

At SOAPHERA we carefully select our oils and butters for what they bring to the skin, not for how cheap they are to source. Every bar in our range is formulated with a specific skin benefit in mind. Our Blue Solace Clay Soap Bar for example uses olive oil and coconut oil as the base, with rare Serbian blue clay added for its detoxifying and pore-cleansing properties. Our Coffee & Turmeric Body Scrub Bar uses the same base with turmeric for brightening and lemon essential oil for a fresh, uplifting scent.

Cold Process Versus Hot Process

You may have also heard of hot process soap making, which uses external heat to speed up the saponification process. Hot process soap is ready to use sooner than cold process and produces a more rustic, textured bar. Both methods retain the glycerin.

Cold process is generally preferred for its smoother texture and the wider range of design possibilities it offers. The slower cure time allows soap makers to create intricate swirls, layers, and patterns that are not possible with hot process. It also allows more delicate additives like certain botanicals and fragrance oils to be incorporated without being destroyed by excessive heat.

Why Commercial Soap is Not Really Soap

Under UK and EU cosmetics regulations, a product can only be labelled as soap if it is made from the saponification of oils and fats. Many commercial bars do not meet this definition and must legally be labelled as beauty bars, cleansing bars, or moisturising bars rather than soap.

Next time you pick up a bar in the supermarket, take a look at the label. If the first ingredients listed are sodium lauryl sulphate, sodium laureth sulphate, or a long list of synthetic surfactants, you are not holding soap. You are holding a detergent bar. It will clean your skin, but it will also strip away the natural oils your skin needs to stay healthy and balanced.

This is particularly problematic for people with dry, sensitive, eczema-prone, or reactive skin. Synthetic detergent bars can disrupt the skin's natural pH and moisture barrier, leading to dryness, tightness, and irritation. Switching to a genuine cold process bar is one of the most effective things you can do for your skin health.

How to Get the Most From Your Cold Process Bar

Cold process soap bars are best cared for with a draining soap dish that allows the bar to dry out completely between uses. A bar that sits in a puddle of water will soften quickly and dissolve much faster than it should.

Store spare bars in a cool, dry place away from direct sunlight. Properly stored, an unused cold process bar will last for up to two years.

If you are new to cold process soap, give your skin a week or two to adjust. After years of using synthetic detergent bars, your skin may take a little time to recalibrate its natural oil production. Most people find that after two weeks their skin feels noticeably softer, more balanced, and less reliant on moisturiser.

Ready to Make the Switch?

If you have never tried a genuine cold process soap bar, we would love to introduce you to what soap can actually be. Browse our full range at SOAPHERA and find the bar that suits your skin.

Every bar we make is cold process, vegan, handmade in small batches, and shipped plastic-free from our home studio in the UK. We think once you try it, you will not go back.