How a Soap Maker Can Increase Lather in Soap Bars

Creating a soap bar with rich, bubbly lather is a goal for many soap makers, as lather is often associated with cleansing efficacy and is one of the more critical components of customer satisfaction.

While soap recipes naturally lather based on their oil composition and additives, there are several ways to enhance this property — and who doesn’t love bigger bubbles!

Below, we’ll explore key methods to increase lather in soap bars.

1. Select High-Lather Oils

The choice of oils is fundamental to soap lather. Some oils produce more lather than others due to their fatty acid composition. For example:

• Coconut Oil: Known for creating big, fluffy bubbles, coconut oil is a go-to for boosting lather. However, it can be drying if used in high percentages (above 30% of the total oils).
• Palm Kernel Oil: Similar to coconut oil, it contributes to lather and adds hardness to the bar.
• Castor Oil: Though not as bubbly on its own, castor oil enhances the solubility of soap, boosting lather when used at 5-10%.

Balancing these oils with conditioning ones like olive or sweet almond oil ensures a bubbly but non-drying bar.

2. Add Lather-Enhancing Ingredients

Specific additives can boost lather by improving the soap’s solubility or bubble stability:

• Sugar: Adding sugar to the lye water increases the bar’s ability to produce lather. A teaspoon of sugar per pound of oils is a good starting point.
• Honey: Similar to sugar, honey adds natural sugars that promote bubbles while also offering moisturizing benefits.
• Beer or Milk: These liquids are rich in sugars and proteins, enhancing both lather and creaminess.
• Glycerin: While naturally formed during saponification, additional glycerin can be added to make the soap more bubbly and moisturizing.

3. Experiment with Sodium Lactate

Sodium lactate, a salt derived from lactic acid, can improve soap texture and longevity. While its primary purpose is to harden bars, it also supports better lather retention by stabilizing bubbles.

We have an entire article on all the incredible benefits of Sodium lactate and why you should add it into your soap. Click Here to read it!

The general rule is to add 1 teaspoon of sodium lactate per pound of oils to your recipe.

4. Use Proper Ratios of Water

The water-to-lye ratio impacts lather formation. Soaps made with less water (a “water discount”) harden faster but may lather less initially.

Ensuring a balanced water amount keeps the bar soluble enough to create bubbles.

5. Incorporate Superfat Wisely

Superfatting, the practice of leaving extra oils unsaponified, is crucial for conditioning but can reduce lather if overdone.

Aim for a Superfat level of 5-8% to strike a balance between moisturizing and bubbly. We make our shop soaps at 5% Superfat always!

6. Formulate for Cleansing Power

Soap with a cleansing value of 15-22 (using a soap calculator like this one over at SoapCalc) often produces more lather without being harsh.

Although this is super technical and nerdy, you can also adjust the recipe’s fatty acid profile, prioritizing lauric and myristic acids for bubble production.

7. Test Additives and Techniques

• Salt Bars: While high-salt soap bars often have creamy rather than bubbly lather, using a small amount of table salt (1 tsp per pound of oils) can enhance hardness and stabilize bubbles.
• Clays: Additives like kaolin clay can stabilize lather, creating a creamy foam.

8. Cure Soap Properly

Proper curing (4-6 weeks for cold-process soap) reduces excess water and improves lather also.

Fully cured bars dissolve more slowly, allowing them to create more consistent bubbles.

By selecting the right oils, incorporating lather-boosting ingredients, and refining your technique, you can create soap bars that delight with rich, luxurious lather.

Experimentation is key—small adjustments can yield big improvements!