Making liquid soap is a bit weird. But it’s not hard. We’re blending lye water and oils to create a soap solution, cooking it down into a gel-like paste, then diluting that as we need it to create a lovely liquid soap. And with two simple oils, this recipe is a great place to start. It creates a beautiful lather without drying your skin. I spent years avoiding the liquid soap making process, thinking it was too complicated. It’s not. I promise you can do this.

Making liquid soap is a bit weird. But it’s not hard. We’re blending lye water and oils to create a soap solution, cooking it down into a gel-like paste, then diluting that as we need it to create a lovely liquid soap. And with two simple oils, this recipe is a great place to start. It creates a beautiful lather without drying your skin. I spent years avoiding the liquid soap making process, thinking it was too complicated. It’s not. I promise you can do this.

A mason jar filled with pale amber liquid soap with a black pump dispenser lid, sitting on a white cloth on a wooden surface with soft-focus flowers in the background.

The 90% coconut oil provides incredible cleaning power and creates those satisfying bubbles we all love. Adding that small 10% of olive oil helps keep the formula balanced and prevents it from being too harsh on your skin. The 5% superfat level means there’s a little extra oil that doesn’t react with the lye, which leaves your skin moisturized rather than stripped.

What makes this recipe different from many others you’ll find is the slightly lower lye amount. This is intentional! While it means your soap won’t be crystal clear, it will be gentler on your skin and suitable for everyone in your family.

This recipe uses potassium hydroxide (KOH) instead of the sodium hydroxide used in bar soaps, which is completely essential for liquid soap.

Cold Process Bar Soap vs. Liquid Soap

The biggest difference is the lye used. Cold process bars use sodium hydroxide (NaOH), while liquid soap requires potassium hydroxide (KOH). This single ingredient swap completely changes the end product. NaOH creates solid bars while KOH creates a soft, dilutable paste. You’ll hear it crackle as you mix it with the water, and is tends to cool off much faster. (I don’t know why!)

Cold process soap is simpler in many ways. Once you reach trace (when oils and lye are fully combined), you simply pour it into molds and wait 24-48 hours for it to harden. It needs 4-6 weeks to fully cure, but there’s no cooking or dilution phase. The liquid soap we’re making here requires that extra cooking step to fully saponify and transform into a paste before dilution.

One thing to note: if you’ve made cold process bars before, don’t assume the measurements will transfer over. Liquid soap recipes need different lye calculations due to KOH’s different chemical properties. Never substitute one lye for another in an existing recipe!

Why Choose Liquid Soap When Bar Soap Is Easier?

Making liquid soap takes more time than cold process bars. So why bother? Here are some practical reasons this extra effort might be worth it for you:

Shared soap bars can be a turnoff for some people. If you have guests often, they’ll probably prefer liquid over reusing a bar your whole family has touched.

And if you have kids, you know the struggle of finding partially dissolved soap bars in puddles around the sink. Liquid soap stays contained and creates less mess.

While bar soap makes a lovely gift, homemade liquid soap is less common and often more appreciated. It’s unexpected and shows extra dedication to your craft.

I first decided to learn liquid soap because I don’t like bar shampoo and my whole family complains about bar dish soap. Sometimes a liquid just works better.

A Look at Each Ingredient in Homemade Liquid Soap

Coconut oil: The workhorse of this recipe, providing excellent cleaning and lathering properties. Use the regular, solid kind you find in grocery stores, not fractionated.

Olive oil: Adds gentleness and conditioning properties. Regular olive oil works perfectly—no need for extra virgin unless that’s all you have.

KOH (Potassium Hydroxide): This is your lye for liquid soap.

Overhead view of soap-making ingredients on a white wooden surface including a bottle of potassium hydroxide flakes, a bowl of coconut oil, a bottle of isopropyl alcohol antiseptic, boric acid, and pink flowers in a cream-colored container.

Slow cooker: The MVP of easy soap making. Using a dedicated one for soap is ideal, but thoroughly cleaned ones can return to food duty.

Stick blender: Saves your arm from hours of manual stirring and ensures thorough mixing. This is not optional—whisking by hand simply won’t work for this recipe.

Scale: Accuracy is ESSENTIAL in soap making. Even small measurement errors can result in soap that’s too harsh or won’t set properly.

Customizing Finished Soap

This is a lovely clear base, for just about anything.

Kitchen Hand Soap: Add 15-20 drops of lemon essential oil per cup of diluted soap. The bright citrus scent cuts through cooking odors like garlic and onion, while the coconut oil base provides plenty of cleaning power for dirty hands.
Shower Gel: Blend in 10 drops of lavender essential oil and 5 drops of vanilla absolute per cup of soap. This combination smells amazing and the lavender adds a gentle calming quality to your evening shower routine.
Foaming Hand Soap: Dilute your soap paste a bit more than usual (about 1 part paste to 3 parts water) and add to a foaming soap dispenser. Add 10-15 drops of tea tree essential oil for its natural antibacterial properties.
Bubble Bath: For a simple bubble bath, dilute the soap paste slightly less than normal (using about 20% less water). Add 15 drops of chamomile essential oil and 1 tablespoon of vegetable glycerin per cup of soap to boost bubbles and add moisture.

Adding Color

Use a colorant specifically formulated for liquid soap, these provide the most reliable results. Add just a few drops after dilution when the soap is below 140°F.

Always add colorants after dilution and cooling. Adding them to the paste can result in uneven distribution or color changes during the cooking process.

Do a small test batch first.
Keep colored soap in opaque containers if using natural colorants, as sunlight can fade them.
Remember that a little goes a long way.
If your soap becomes cloudy after adding colorants, that’s normal and won’t affect the soap’s performance.

A Note About Storing Liquid Soap

The way you store your liquid soap makes all the difference in how long it lasts.

Undiluted soap paste is your best friend for long-term storage: it can last up to a year in an airtight container in a cool, dark place with virtually no risk of spoilage. This is because the high pH environment is naturally hostile to most bacteria and molds.

Once you dilute the paste with water, however, the clock starts ticking.

Without preservatives, diluted liquid soap typically stays good for 3-6 months, depending on storage conditions and how clean you keep the container. While some soapmakers add preservatives like Optiphen or Liquid Germall Plus after dilution, many find it unnecessary if you’re making small batches for personal use.

I prefer to store most of my soap as paste and just dilute what I’ll use within a month or two. If you notice any unusual odor, separation that doesn’t mix back together when shaken, or visible mold in your diluted soap, it’s time to toss it.

Always use distilled water for dilution, as tap water contains minerals and potential contaminants that can reduce shelf life and affect clarity. I don’t always do this, but I should.

There’s nothing quite like the feeling of washing your hands with soap you crafted yourself, a small daily reminder that you can create rather than just consume. Have fun!

Prep Time:30

Cook Time:40

Cooking:3

Total Time:4 10

Equipment

Slow cooker or very large pot
Stick blender
Heat-safe glass or plastic container for mixing lye
Stainless steel or heatproof plastic mixing spoon
Gloves, goggles, and safety gear
Scale (for accurate weighing)
Thermometer
Plastic sheeting + bungee cord (optional, for sealed cook method)
Mason jars or bottles for storage

Ingredients

9.3 ounces Potassium Hydroxide
29.4 ounces Water for mixing with lye
31.75 ounces Coconut Oil
3.5 ounces Olive Oil
5.3 ounces Alcohol
50 ounces Distilled Water for dilution

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Instructions

Make the Lye Solution. Put on gloves and goggles for safety. Weigh 264g (9.3 oz) of KOH and 834g (29.4 oz) of water separately. Slowly add the KOH to the water (NEVER the other way around).Stir until fully dissolved. The solution will get very hot you will also hear a crackling sound as you stir. All normal! Set aside in a very place to cool.
Heat the Oils. Weigh and add 900g (31.75 oz) of coconut oil and 100g (3.5 oz) of olive oil into a slow cooker or stainless steel pot. Turn slow cooker on high to let melt directly in there. To speed up the process, melt the oils in a pan on the stovetop on low.
Let both components cool. Let the lye water cool down until it is clear, not cloudy. Let the oils cool slightly until the pan or slow cooker is warm but not too hot to the touch.
Mix the Lye Solution with Oils. Slowly pour the cooled lye solution into the melted oils. If you’re using the alcohol, add it now. Begin mixing with a stick blender in short bursts until it is well combined. If you aren’t using the alcohol this will take awhile and you may only reach a thin trace. If you are, it will go a bit faster. Make completely sure there are no visible spots of oil before moving on to the next step.
Cook the Soap Paste. Turn the slow cooker to medium or high heat or set large pot on very low heat on electric stove or hot plate. Place the soap batter inside and cover. Cover the slow cooker with plastic sheeting and secure it tightly with a bungee cord (optional, this makes sure the alcohol does not evaporate off and keeps the heat in.) (Do not use gas.) Stir occasionally while cooking for 2–3 hours, until the mixture becomes thick and translucent. The soap is ready when it reaches a gel-like, translucent consistency and passes the zap test. It will be relatively solid, like playdoh. If there’s still liquid in there, keep cooking. Note: some people like to weigh the full pot before and after cooking, then add more alcohol in to replace any that burns off. I don’t do this, but just accept a small amount will evaporate.
Store Paste. This process leaves you with a paste that you will then dilute to use as a finished product. I prefer to store the gel paste and then dilute it as I need it. But if you’d like to dilute the whole batch, you can.
Dilute. Be aware that if you don’t go through your soap quickly, mold is a possibility once water is added. The general rule of dilution is: 1 part distilled water to 1 part soap paste. You can heat the water and blend it if you’re in a hurry, but I just let it sit overnight and it’s diluted in the morning. Go slowly, it’s always easy to add more water.
Add color or fragrance if desired. Add essential oil, fragrance oil, or liquid colorant if desired. The amount needed will depend on the specific oil.
Bottle and Store. Pour the finished soap into pump bottles, mason jars, or dispensers. It will be cloudy at first but will become clearer over the next 1-2 weeks.

Notes

Commercial soaps have a lot of glycerin and other additives to make them thicker, so this will seem thin to you. But don’t use too much, there’s still lots of lather and cleansing properties.

This is slightly lower in lye than most liquid soap formulas which keeps it gentle on your skin and good for the whole family. But because of this it will never be crystal clear.

You can do this on a stovetop on very low heat, but it’s quite dangerous. You’ll need to trim the plastic and keep an extremely close eye on everything. At some point the soap with puff up as it cooks, and if any leaks out, the alcohol in it makes it very flammable. I don’t recommend it.

Servings: quart soap paste (make 1/2 gallon soap)

Author: Katie

Simple Liquid Soap You Can Make at Home (Coconut & Olive Oil)