Soap making is not hard to do if you are armed with just a little bit of information. Soap is the result of combining fats with a caustic agent such as lye using water as a catalyst. It is possible to turn out a nice batch of soap with simple things that can be purchased at most grocery stores. Read on to get the specifics on this fun and interesting hobby.
- Water: For best results, use rain, distilled, reverse osmosis or de-mineralized water. Your water should be 0.38 of your fat by weight. Don't worry too much about getting it exact, however, as this measurement isn't terribly critical.
- Lye: You should know a little bit about lye, or sodium hydroxide. Lye is a very strong base. If you get it on you, you will find it's bad stuff. (Be sure to store lye where kids or pets can NEVER get at it.) You must use care in determining what utensils and mixing containers you use when handling lye. Use wooden or plastic spoons and enameled, plastic or glass bowls for mixing. (Lye will eat up Aluminum in a hurry. Also, lye instantly and permanently takes the shine off Formica. Caution to table tops and counter tops should be used as it can leave a permanent streak. It may be better to work outside on older tables. It is also recommended you wear eye protection and rubber gloves when handling the lye crystals or the lye solution after you have mixed it into the water.Dissolve lye in cold water. Having half your water as ice would be so much the better. Never pour the water into the lye. Doing this could cause the mixture to explode and blow very corrosive lye water and crystals all over the place. Rather, always pour the lye into the water. If you don't stir it immediately as you pour the lye into the water, the lye will settle to the bottom and quickly solidify. This isn't a problem as tapping it with the stirring utensil will break it up. As you mix it, a physical reaction takes place between the lye and the water generating a lot of heat. If you are making a large batch of soap, the lye can even start the water boiling - with little droplets of lye water splattering all over the place. If this starts happening, stop stirring it until the bubbling stops. Generally, it doesn't take more than a minute to dissolve the lye crystals into the water. You know this has happened as the water will become relatively clear. Before using, the lye water must now cool down to about 85 degrees F (or room temperature if your mixing area's above 85 degrees) before adding it to the fat.
- Fats and Oils used in soap making. Most often almost any fat or oil can be used to make soap. Fats for soap making include animal fats such as tallow (fat from beef), lard (fat from pork), and the various plant derived oils and hydrogenated fats. Traditionally, animal fats have been used, with beef tallow making the hardest soap, pork lard a medium hardness soap and chicken fat the softest. It's generally accepted that the harder fats make better soap.
There are a multitude of fats and they each bring their own unique qualities to soap. If you want to know what a particular fat will do, make a small batch of only that fat and see what kind of bar it makes. Armed with this knowledge you can mix fats to give your soap the qualities you want. This is how soap recipes are born.
Whatever type of fat or oil you use, you must ensure it is clean and free of impurities. It shouldn't be rancid, have excess salt in it, or have any solid particles. (Many people remember the soap grandma used to make, and have unpleasant memories of nasty smelling stuff. If Grandma had used clean, fresh, fat, her soap would have smelled clean and fresh. But we can't blame Grandma as she did the best she could with what she had).
Rancid and dirty fat can be cleaned by boiling it for a few minutes in a large pot with four parts water to one part fat. Set it aside and let it cool. After it has solidified, remove the fat from the pot in one piece. One way to do this is to run hot water around the outside of the pot, melting a thin layer of fat next to the pan. It should then slide out. Scrape all the foreign matter off the bottom of the fat. If it is still dirty, repeat the cleaning process again. It is also fairly easy to render your own fat.
What are your best fats for soap making? Amazingly, the soap making professionals feel that lard beats tallow and vegetable oils for gentleness to your skin. However, soap made with 100% lard doesn't lather very well. But it cleans beautifully. There is a predominant idea today that you must get bubbles for the soap to do its job. Soap making professionals have told me this is not the case. But if you want bubbles, you can have the kind of bubbles you want by using different oils.
- Different Fats that create bubbles:
- Coconut Oil gives big, fluffy bubbles. One hundred percent coconut oil soap is sometimes used around maritime operations as it will even lather in sea water, really, about the only soap that will. Soap with coconut oil can be a tiny bit harsh on some people's skin. If you'd like cheap coconut oil, get a one or five gallon bucket of popcorn popping oil which is 100% coconut oil that's dyed yellow. Yes, you will be stuck with yellow soap but this won't be a problem for most people.
- Olive oil gives very fine, silky bubbles. This oil is very good for the skin.
In your soap making, use at least 25% of these fats as part of your overall fat to get the desired effect you're seeking.
- Saponification (Sap) Value: Each fat requires a different amount of lye to change the fat to soap. See our Lye to Fat Ratio Table Page for a short discussion on this and a listing of different fats and the lye required to convert them to soap.
The temperature of the fat is important. It needs to be a bit above it�s melting point. This is 130 degrees F for beef tallow, or 85 degrees F for pork lard, or about the same temperature for vegetable oil. The hotter your oil, the faster the chemical reaction between the lye and the fat. But the hotter the oil, the easier the soap separates into layers during the mixing stage.
- Mixing: With the lye water and fat at the right temperature, very gradually pour the lye water into the fat using a very small stream. Stir gently only in one direction the whole time you are adding the lye water. This helps it mix. You should insulate your mixing pot with old rags, etc, to prevent the fat from hardening before you've finished mixing the soap.
- Saponification and its role in the mixing process: Simply stated, saponification is the name for the chemical process that happens between lye and fat as they turn into soap. It doesn't happen all at once, but actually takes days to complete. There are different levels of this process, and the most important one for you to know about is the "Trace" stage. This is the point at which your soap has thickened up somewhat. As you let the soap run off your mixing spoon back into the mixture, the falling soap stays on top and doesn't blend in, but leaves its "trace" mark on top. Its thickness is another way to know when trace occurs. Its consistency is much like the thickness of pudding after it's cooked but before it has set up.
With stirring only, it can take a long time to get your soap to the trace stage depending on many variables. One of these variables is the heavyness of the fat. The lighter the fat or oil, the longer it will take it to trace. You can expect a wait anywhere from 30-60 minutes for animal fats to several hours or even days for the vegetable oils. Does this mean you need to sit and stir your soap for several hours until it traces? I don't. After mixing it for about 15 minutes, I do other things and mix the settled layers back up every 15 or 20 minutes when I happen to go by it. (You may wish to set your timer so you don't completely forget it!) At the trace stage of thickness, it won't separate out into layers when you pour it in your setting trays or molds.
- A False Trace can happen when making soap with fats that are solid at room temperature, such as tallow, lard, or shortening. If the temperature of your soap mix drops below the melting temperature of your fat, it will start to solidify. As it does, your batch will start to thicken up just like it was tracing - but it's not! Rather, it's the fats solidifying. To prevent this from happening, be sure that the soap you are mixing stays above the melting temperature of the fat. In fact, the warmer your soap, the quicker it will saponify. It wouldn't hurt to keep your soap up to around 115 degrees F to speed this process along a little more quickly. At 120 degrees F lanolin will curdle your batch, so sometimes, depending on the additives you've included, you may need to be very careful how hot you get it.
- Vegetable oils can also be used for making soap. These oils are liquid at room temperature and without employing a trick or two usually require many hours of mixing before they trace.
Trick 1: Use a blender. The more finely the lye and fat molecules are intermixed the faster they will saponify. Using a blender, the trace stage can be reached in minutes instead of hours. Don't use an upright blender unless you don't mind millions of tiny air bubbles being permanently whipped into your soap. Use the hand-held type instead. With one of these, even your most stubborn oils should trace within 20 minutes. Sometimes, you can get a trace with animal fats in just a couple of minutes. Anyone who has sat around for hours stirring a batch of soap will be ecstatic with this.
Trick 2: Cook it. There are a couple of processes that I have developed myself yet are rather unorthodox. And this is one of them. If you don't have a blender, perhaps cooking your soap is for you. See our soap cooking page for more details. After it has cooled, pour or spoon it into the soap mold or tray and treat it like you would for the no-cook recipes. Even though it has been cooked, the chemical reaction that slowly turns liquid vegetable oils into soap will take much longer than cooked animal fat soaps.
When your soap has traced you can add
your superfatting, coloring and perfume oils.
- Superfatting oil: When your soap gets to its trace stage, the saponification process is around 90% complete. Fat added at this point makes your soap softer. There is a reason why the superfatting oil is added after tracing instead of at the beginning with all the other fats. If it was added at the beginning you wouldn't have any control over which fat or oil ended up as your 'free fat'as all fats would saponify together. This is presupposing you are going to superfat with a different fat or oil than you used to make your soap with. Exotic oils are generally used in superfatting. They are added at trace to give the benefit of their desirable qualities without having to use so much it empties your wallet. A good rule of thumb is to use 1 oz. per pound of total fat used in the recipe. (That's one part superfatting oil to 16 parts total fat.) Let me list just 2 of the more common superfatting oils:
- Avocado Oil:Feels very soft to the skin and makes an excellent shaving soap.
- Cocoa Butter: Makes a hard bar. It smells and looks nice, but doesn't lather.
- Coloring Dyes: Several things are used to color soap. Approved items are clays, mineral pigments and spices. You can get these items from soap supply companies. Moving back into the area of unorthodoxy again, I color all my soap with a piece of crayon. Virtually all crayon is made with stearic acid, a type of fat. The stearic acid saponifies into the soap leaving behind the pigment.
I melt crayon into my soap after it has traced. Don't be tempted to put your crayon in at the beginning as the lye will change its color. You may need to heat a half cup or so of your traced soap to about 150 degrees F to get it to the melting temperature of the crayon. Even adding a crayon at this late stage of mixing, you may notice a slight color shift over time.
- Scenting Oils: There are two types of scenting oils, FO's (fragrance oils) and EO's (essential oils). An EO is made from distilling the oil out of the plant it comes from. A fragrance oil is a man-made chemical that's steeped in alcohol. EO's are usually used in soap making as FO's have been known to seize soap, or turn it into a yucky ball that doesn't saponify correctly. EO's are much more expensive and harder to find than FO's but also have better scent retention. If it is an EO, it will most often say so on the label. You will also know it by the exorbitant cost. FOs can often be used safely at trace however. Make a small test batch first to see if your FO is going to work before making a big batch. Be aware that rose and cucumber FOs are notorious for seizing soap. If you want to use an FO that can possibly seize soap, you can safely use it during a rebatch. Certain fragrance oils and essential oils change the saponification characteristics of a mix. Jasmine absolute from real flowers is damaged by strong alkali. It is a natural fragrance and not a fragrance oil.
- The Setting Tray: In past days a galvanized tub was used. Other old timers used a wooden box in the shape of a tray with a cloth laid in the bottom of it. The cloth was used to help remove the hardened soap from the tray. If you are going to use a solid tray, it is recomended using plastic wrap instead of cloth as a barrier between your soap and the tray. But there is something even simpler than this. If you have any square edged, flexible plastic trays with lips at least as high as a bar of soap is thick, use this instead. After the soap has hardened, a slight flexing of the tray will dislodge the soap. When the soap begins to harden (1 hour to 3 days depending on how fast the curing process is moving along), section it into bars. When cutting, the soap should still be soft enough to easily run a table knife through it but hard enough that the soap doesn't run back together again. After it has further hardened (3-7 days), remove it from the tray, and break it into bars following the knife marks made earlier. Even though your soap looks hard at this stage, it is far from done. There's a good chance it contains a bit of lye that should dissipate into the soap as the saponification process continues. This will be true as long as you had your lye/fat ratio correct in the first place. Your soap will need to sit for 2-6 weeks to dry out and cure, depending on the fat you used. Use litmus paper to test the lye content of your finished soap. Be sure to wash off any soda ash that has formed before testing. Soda ash has a high pH value. Your soap should be below a pH of 10 within 36-72 hours after it has traced. The closer the pH of the finished soap is to 7 the better but don't expect normally made soap to reach this. If your soap is over a pH of 10, let it sit around for a week or two. Hopefully as the soap continues to saponify the lye will get transformed and the pH will drop. Your soap should be below a pH of 10 before you use it. Below a pH of 9 would be better. There are a few seasoned soap makers that test the pH by tasting the soap. Your tongue will tingle if there is still too much lye in it. Of course, it is not wise for you to swallow this stuff.
- Final Curing and Storage:With the soap out of the tray or molds, stack it up and set it in a warm dry place for at least two weeks. When it has fully cured, place it in a plastic bag or air tight container, and store it in a cool, dry place. You might notice a thin, white powdery layer on the outside of your soap. This is soda ash, and forms as a result of the carbon dioxide in the air interacting with the lye in the soap. This outer layer quickly washes off the first time you use it. If this is a concern, cover your setting soap with plastic wrap so the air can't get to it. After saponification nears completion, you can remove the air barrier to let your soap dry out. After all this, if there is still a thin layer of soda ash on your soap after it has cured, wash it off, then let the surface of your soap dry before storage.