To make biodegradable liquid soap, you can follow a recipe using castile soap and other natural ingredients. However, it's important to understand that borax and washing soda, while often included in homemade detergent recipes, are not biodegradable and may have environmental concerns. A truly biodegradable recipe should avoid these. This answer provides both a common recipe and a more genuinely biodegradable option.
Common Recipe (Borax/Washing Soda Included)
This recipe is often shared online. Note the comments below regarding biodegradability.
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Prepare the Castile Soap: Shave 1/2 bar of castile soap into a couple of cups of water. Bring the mixture to a boil, then reduce heat and simmer until the soap melts completely. Alternatively, you can use unscented liquid castile soap to skip this step.
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Combine Dry Ingredients: In a large bucket, add 1 cup of borax and 1 cup of washing soda.
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Mix Soap and Dry Ingredients: Add the melted castile soap mixture to the bucket with the borax and washing soda.
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Add Water: Add approximately 5 quarts of water to the bucket. Stir well to combine all the ingredients.
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Let it Sit: Allow the mixture to sit for 24 hours to thicken. Stir again before using.
Important Considerations: While often referred to as "natural," borax and washing soda are not biodegradable. Borax, specifically, has environmental concerns related to potential harm to aquatic life and soil organisms in high concentrations. "Biodegradable" by definition means a substance is capable of being broken down by living microorganisms into simple, stable compounds such as carbon dioxide, water, and mineral salts. Neither borax nor washing soda fit this definition.
More Genuinely Biodegradable Option
To create a more truly biodegradable liquid soap, focus on castile soap alone, or combine it with other plant-based ingredients.
Ingredients:
- 1 cup liquid unscented castile soap (e.g., Dr. Bronner's)
- 1/2 cup distilled water
- Optional: 10-20 drops of essential oil (e.g., lavender, tea tree) for scent and antibacterial properties.
Instructions:
- Combine Ingredients: In a clean bottle or container, mix the castile soap and distilled water.
- Add Essential Oils (Optional): If desired, add the essential oils and stir gently.
- Shake Well: Shake the mixture well before each use.
Why this is more biodegradable: Castile soap is made from plant-based oils and is readily biodegradable. Distilled water is simply water, and essential oils are natural plant extracts that will also biodegrade.
Usage: Use as you would any other liquid soap. A little goes a long way.
Storage: Store in a cool, dark place. Homemade soap does not contain preservatives, so it may have a shorter shelf life than commercially produced soaps. Use within a few months.
