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How To Make Handmade Soap Using Cooking Oils Or Fats
Everyone of us loves fried food, right?
No matter what cooking oil we use when frying our chicken wings or french fries, when the food is done most of us will either keep the oil for one more frying session and then throw it away, or throw it away at once. It is well known however that cooking oil should not be simply thrown in the drain because it is quite harmful to the environment; instead it must be recycled.
As far as I know, most countries have places where oil can be recycled and then it is used either on biodiesel production or for soapmaking.
This hub will show you a basic recipe that works for corn oil, sunflower oil, palm oil or other types of cooking oil. The method which will be shown is called cold process and is way different from the "melt and pour" way. Follow the steps carefully and you will be able to make your own handmade soap using something you would otherwise get rid of.
The basic recipe is as follows:
- 1 kg of cooking oil
- 128 g of NaOH
- 300 mL of water
- (not necessary) essential oils for scenting
Some notes on the ingredients, before we move on with the process.
Cooking oil should of course be as clean as possible; to achieve this, let it pass through very thin strainer multiple times so that food leftovers and debris can be removed.
NaOH is a chemical product, also called caustic soda. It comes either in powder or little flakes, or in water solution. I suggest flakes form, because it can be handled more safely - it can cause irritation at skin due to its alcalic nature (pH=14) and can generate extreme chemical reaction if let to react with metals. When working with NaOH, you should be wearing gloves, use always non-metallic containers (unless you have stainless steel cookware) and take extreme care so you will not cause splashes.
You can opt to add essential oils of your preferred scent in the soap mixture, so that the resulting soap will smell nicely. Choose essential oils that are skin-friendly
Step By Step: The Process
Having a digital scale is a large advantage; the amounts should be weighed accurately (the water is an exception to this rule, since it does not affect the saponification itself) in order to achieve a perfect soap.
1. Prepare your oil; that means, clean and let it cool. Weigh it carefully and place aside.
2. Add the water in a container and move it at a well ventilated place, or outside.
3. Measure 128 g of NaOH and place it outside, next to the container with water.
4. Be very cautious in this step! Use a spoon or laddle to start placing the caustic soda in the water. Do it few flakes and not all at once. When the soda drops in water, a chemical reaction will begin and the water temperature will increase rapidly. The mixture should be stirred carefully so all NaOH dissolves in the water completely. Do not inhale the fumes which are generated form the nearly-boiling water at this stage (it is why it would be preferable to do it outside).
5. The soda solution should now be let to cool back to room temperature, because when it mixes with oil both mixtures should have equal temperature. You might have to let the solution cool for half an hour. If you are in rush, place the container in another container with ice cubes and cold water. For even better results, you could use an infrared (IR) thermometer or a thermometer probe to check and compare the two mixtures temperature.
6. Pour the oil inside the container with the soda solution. Get prepared for vigorous stirring!
7. Stir the mixture with a large stirrer or mix it with a hand mixer (with stainless steel endings). The stirring should be vigorous yet careful, splashes are still dangerous for your skin. A hand mixer will achieve faster results than a stirrer, of course. You would want to stir for 20-30 minutes, until the mixture enters the so-called "trace phase". You will recognize when you can stop, because the mixture will be quite thicker and will be able to support a drop without it moving through the mixture to the bottom at once. Additionally, the stirrer will leave trace marks which will stay for couple of moments.
8. If you are planning on adding a scent, now is the time to drop your essential oils in the mixture. Stir it lightly so that it spreads throughout your soap mix.
9. When tracing has occurred, you can pour the mixture in a plastic or wooden molder (which you have covered with baking paper for more ease) and let it dry. Drying in the molder will take approximately 48 hours.
10. After 2 days or so, check the surface of the soap; it should be ready to unmold by now, but it will not be completely dry.
11. When the soap has been removed form the molder, place it on a flat surface and cut it in bars according to your personal taste. Do not bother much if the edges of the soap are not perfectly flat and straight.
12. Now that the bars of soap have been prepared, you need to let them aside to dry for long; 3 months of drying is a completely safe time; make it 2 months if you feel too excited to use your soap. Let it dry on a flat surface, covered with a towel so that insects or dirt will not affect your soaps.
Some Pieces Of Advice
Making handmade soap, as you understand, can be a fun process and an interesting hobby for you. Aside the obvious advantages of recycling (for nature), you will obtain a very useful cleaning product (way better quality than the commercially bought soap bars!) which you will use for your needs, gift to your friends or even sell.
However, the process involves some risks that could ruin the soap you are making or even worse, create soaps which will cause skin irritation. Particular care should be taken in all steps of the process.
The biggest mistake you could possibly make is throw the water in the NaOH, instead of slowly placing NaOH in water. The sudden "meeting" of the two ingredients will cause a violent eruption ( read:explosion). This is the most dangerous part of the whole process; do not take my warnings lightly please, for your own good.
The ratios of the ingredients I have given will create a soap with 5% fat; this means that not all fat of the oils will be saponified by the NaOH. A 5% fat is widely suggested, because this will make sure that all NaOH has been "consumed" - you wouldn't want to have remaining NaOH in the soap, because the soap would be too alcalic and caustic and would create skin rashes. By setting the ratios the way they are set in this "recipe", we are on the safe side (this 5%) even if slight miscalculations occur.
When the soap has been unmolded, you can work on each bar to correct minor visual issues they might be encountering; some bars tend to have cracked edges or generally look crippled at their sides after they have been removed from the mold. With a knife you can fix such problems by cutting through through the soap and removing the parts that don't look good.
Testing The Soap's pH
If you do not wish to wait for 3 months, you can try the soap when 2 months have passed. Other recipes I have come across online decrease this drying time to 1month or even less; I would not try a soap which has dried for less than 2 months, that's for sure. Saponification does take a long time.
Anyway; if you are really excited to use your soap when 2 months have passed, try a bar on your hands first and let it aside. For the next minutes, watch your hands for slight burning feelings or sense of discomfort and skin irritation signs. If you do not feel anything weird, then the soap is safe to use.
If you want to be 100% sure for your soap, a pH tester is advised. You can easily find inexpensive pH strips packages; they usually include a large amount of pH strips which you dip inside a water solution of your soap and then compare their color with the colors shown at the box. Generally, anything below pH 10 is safe to use, but personally I choose to wait until the soaps I create are pH 9 or less. Other ways of testing the soaps' pH is digital pH testers, available commercially.
Storing And Packaging
Storing your soaps is another thing you will have to think of, especially if you are making large batches of soaps which will, in time, take large of your space. Find a well ventilated, relatively dry and not too cold or too hot space for your soaps. Place them on a baking sheet on their sides (depending on the shapes you had cut them on) and rotate them often, like once per week, so they dry from all their sides.
When they are dry and pH-tested, you can wrap them to keep them clean; use simple baking sheet or even printing paper to wrap your soaps. You can print labels with details on them (such as ingredients, date, or even your own brand logo!), thus creating a product which could easily sell for some cash.
A wrapped soap is safe from humidity and dust/dirt, and should last for many years.
I hope that this soap making guide will help you in creating your own, handmade soap and give you a new exciting hobby. Please let me know if you have any comments or corrections.