
It is becoming more and more common to use natural and homemade products, precisely because of the benefits they have for health and the environment, and why not? also to the pleasure of making this type of products yourself in our own home. In this sense, one of the most widespread products is natural soap, which can be easily made in our own home using caustic soda, used cooking oil and water. If you want to know how to make homemade soap with used oil keep reading Green Ecologist and we'll tell you about it.
Steps to make homemade soap before you start
One of the most important aspects when preparing homemade soap from used oil is to bear in mind that it is a chemical process that, although it does not have to pose a danger if it is done properly, it is necessary that is done with due care to avoid setbacks or possible accidents. This is mainly due to the fact that caustic soda (one of the ingredients to make homemade soap) reacts chemically with the other elements that are part of the recipe and can be dangerous if not treated properly.
In this sense, the first thing we have to keep in mind is that it is important that we carry out the elaboration in a well ventilated place, better outdoors if possible, since the chemical reaction that we are going to carry out will release gases that can irritate the eyes and respiratory tract.
Second, it is important that we protect ourselves properly, both to ourselves and to the clothes we wear. It is recommended to wear protective gloves, an apron, comfortable clothing suitable for this job, as well as protective glasses.
In third place, use a stainless steel container and not of another material such as iron, aluminum or plastic, since it could react chemically or even melt in the case of plastic.
Finally, it is also important to keep in mind that, although it is a very fun task for the little ones, it is important watch the children correctly and explain that they should not get too close to the formula, much less touch it.

How to make homemade soap with used oil?
The ingredients and measurements that we are going to need to elaborate the homemade soap with used oil are as follows:
- 1 kilo of used oil
- 345 grams of distilled water
- 135 grams of caustic soda
Here we explain how to make homemade soap step by step:
- The first thing we should do is strain the used oil to remove any impurities it may have from its old use in the kitchen. Once we have it strained we will reserve it.
- Next, in a stainless steel container, we will pour the water, and we will go incorporating caustic soda slowly and gradually. This will produce a chemical reaction that will release vapors that are irritating, so it is important that it is done in a clear place and that you avoid breathing directly into the container. This mixture is known as caustic lye, and it can reach a temperature close to 80 degrees.
- To completely dilute the caustic soda in the water we can help ourselves with a wooden or stainless steel stick. Once it's dissolved we'll let them pass a few minutes until cool.
- Then, keeping the oil in another stainless steel container and at the same temperature as the caustic bleach, we will pour the caustic bleach slowly on the oil and we will stir with a stick of the same characteristics as the one used in the previous step. This step will best be done between two or more people.
- It is important stir the mixture constantly and always in the same direction to avoid being cut.
- Once all the ingredients have been mixed, we will continue stirring until we obtain a perfectly homogeneous mixture. At this point, it will be when you can add color pigments and scent oils to give it healthy and aromatic properties.
- Finally, we will pour the mixture into the soap molds corresponding (which now can be made of plastic or silicone) to let it cool and we will cover them with a cloth so that they do not lose temperature too quickly and the mixture can be cut.
- The molds can be unmold after 48 hours. However, it is recommended to let the soap harden for at least a month. After this time, it can be used like any regular soap.
Why is it important not to throw away used oil?
The use of used oil to make soaps is one of the many options available to dispose of this waste so common in homes. Another option, simpler but less creative, is store it in a plastic bottle and take it to the nearest clean point so that it is managed effectively and not dangerously.
The problem with used oils is that they have a very high polluting power. One liter of oil can contaminate up to 1,000 liters of water. This is mainly due to the fact that, weighing less than water, the oil ends up covering the surface of lakes and rivers. Consequently, the water cannot be properly oxygenated, which implies the destruction of both the flora and the fauna associated with these ecosystems, which, in addition, are also often related to the neighboring ecosystems, so that the effects are very dangerous for the environment. For this reason, it is essential that we never dispose of oil down the drains or directly into the environment, but rather that we manage it efficiently in a clean room or in the production of soaps or other artisan products. In the following article we explain what to do with used cooking oil.

If you want to read more articles similar to How to make homemade soap with used oil, we recommend that you enter our category of Crafts with recycled material.