Making liquid soap

Summary

In this detailed video, the creator takes viewers through the process of making liquid soap using the hot process method. Starting with the same oils used for solid soap, the creator explains the importance of potassium hydroxide over sodium hydroxide for creating liquid soap. They cover essential steps, including mixing the ingredients in a slow cooker, neutralizing excess base with borax, and testing for completion. The video also explores the science behind soap-making and includes a fun twist with fluorescent green soap. The creator finishes by demonstrating the soap's functionality, sharing tips, and promoting their Patreon supporters.

Takeaways

• 😀 The soap-making process involves both cold and hot methods, with the current video focusing on the hot process for making liquid soap.
• 😀 Potassium hydroxide (KOH) is used for liquid soap, in contrast to sodium hydroxide (NaOH) used for solid soap.
• 😀 The base oils used for both soap types are similar, but more coconut oil is used for liquid soap to enhance lather.
• 😀 Borax is added to the liquid soap recipe to help with thickening and can also neutralize excess potassium hydroxide.
• 😀 The hot process method speeds up soap-making by utilizing heat, cutting down the reaction time from weeks to just a few hours.
• 😀 Potassium fatty acid salts, formed in the hot process, create a softer and more water-soluble soap, which is why it's ideal for liquid soap.
• 😀 To ensure the soap is free from excess base, a test is performed by dissolving a small amount of soap in boiling water, ensuring it forms a clear solution.
• 😀 If the soap has an excess of base, it can lead to irritation, but this can be corrected by neutralizing with borax or other agents like citric acid.
• 😀 The soap is tested for pH, aiming for a range between 9-10, and if it's above 10, neutralization is required.
• 😀 Once the soap is finished, additives like fluorescein can be used for visual effects, although caution is needed when adding it to soap for skin use.
• 😀 After completing the soap, it can be stored and used for various purposes, such as cleaning glassware, but should not be used on the skin if fluorescein is included.

Q & A

What is the difference between the cold and hot soap-making processes?

The cold process soap-making involves mixing oils with sodium hydroxide at room temperature and letting it cure for weeks, while the hot process uses potassium hydroxide, heat, and a faster reaction time, completing the soap within a few hours.

Why is potassium hydroxide used in liquid soap making instead of sodium hydroxide?

Potassium hydroxide is used in liquid soap because it forms potassium salts of fatty acids, which are more water-soluble and create a softer, liquid soap compared to the sodium salts formed with sodium hydroxide in solid soap.

What role does coconut oil play in the liquid soap recipe?

Coconut oil is used because it contains shorter fatty acids that help create a better lather, which is especially important in liquid soaps.

What is the purpose of using borax in the liquid soap-making process?

Borax acts as both a neutralizing agent to remove excess potassium hydroxide and as a thickening agent, helping to maintain the desired consistency of the soap.

Why is it important to test the pH of the soap?

Testing the pH ensures that there is no excess base (potassium hydroxide) left in the soap, which could cause skin irritation. Ideally, the pH should be below 10 for safe use.

What does it mean when the soap reaches a 'thick trace' during the hot process?

A 'thick trace' refers to the stage in soap-making when the soap paste becomes thick and somewhat translucent, indicating that the chemical reaction is complete and the soap is ready for dilution and further processing.

How is the soap tested for completion in this video?

The soap is tested by dissolving a sample in boiling water. If the soap dissolves completely into a clear solution, it indicates that the soap is ready. If it doesn’t dissolve, it needs more cooking time.

What is the purpose of adding distilled water to the soap base?

The distilled water is added to dilute the concentrated soap paste, making it easier to use as liquid soap. The amount of water added determines the soap's final consistency.

Why is fluorescein added to the soap, and what effect does it have?

Fluorescein is added for visual effect, making the soap fluoresce under UV light. However, it is not recommended for soaps used on skin due to potential irritation, and it's only used in this video for cleaning glassware.

What is the significance of the chemical rule of thumb mentioned about temperature and reaction time?

The rule suggests that for every 10°C increase in temperature, the reaction rate doubles. In this case, heating the soap paste speeds up the reaction, reducing the time needed for soap completion from two weeks (cold process) to just a few hours (hot process).