People love Dr. Bronner's castille soap, but if you've ever tried to use it instead of shampoo, you may have noticed that it didn't leave your hair feeling very clean. Unlike regular shampoo, the soap will react with the minerals in the water depositing a white film in your hair. Usually when we see this white film buildup in a tub, it's called soap scum.
Soap scum in and of itself is not dirty and can be rinsed away easily with an acid rinse leaving your hair feeling clean and shiny. In this instructable, we'll use food grade citric acid powder dissolved in water for the acid rinse.
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Step 1: Make Your Citric Acid Rise
You can find food grade citric acid in most large grocery stores but it's much less expensive if you buy by the pound online. To make the rinse, you will want to mix in 1 Tablespoon of citric acid powder for every 8 fluid ounces (1 cup) of water. For our example, you will be prepping 32 fluid ounces of acid rinse:
- Microwave 8 fl. oz. (same as 1 cup) of water until it's hot in a 32 fl. oz. glass container
- Remove the water from the microwave and mix in 4 Tablespoons (same as 1/4 cup) of citric acid powder
- Mix until the solution has turned clear
- Add 24 fl. oz. of cool or room temperature water to the glass container so that it now contains 32 fl. oz. total of solution
- The solution should now be cool enough that it is pourable into a plastic container that you can put in your shower
Step 2: Get Clean With Dr. Bronner's
Use the castille soap to suds up you hair and then rinse with water just like you normally would with shampoo. This will remove the grease and grime from your hair but will leave a residue from the water if you don't follow up with the next step. Be sure that you've rinsed all the soap away with water before proceeding to the acid rinse.
Step 3: Follow Up With Citric Acid Rinse
Take care not to get the rinse in your eyes since it can sting. Use a liberal amount of the citric acid solution to rinse your hair so that it has a chance to remove the minerals from the water that might be there. It would not be unusual to use 1/2 cup on long hair. The ingredients are cheap, so use more than you think you might need the first time just to make sure you get the results. You will get better at using just the right amount with practice.
Follow up the acid rinse by rinsing again with water. You should be able to run your fingers through your hair without much tangling.