Making Transparent Soap
A great number of people who want to make their own soap are drawn to transparent soap because of its beauty. With some alterations in ingredients, you can use the hot-process technique you've already learned to make incredible transparent soap. This from-scratch soap cannot be easily melted and molded, but it is beautiful in its own right.
The addition of sugar and alcohol are the best ways to make transparent or at least translucent soap at home. Commercially, the process involves pressure and extreme temperatures. At home, it is an extension of the cold-and hot-process techniques.
If you are tempted to make transparent lye soap your first project, resist the temptation, or at least have an experienced soaper help you. Lye soap-making from scratch is daunting enough the first time without the added variables introduced with this technique.
Before you make transparent soap, be sure you have made a number of batches of both cold-process and hot-process soap. Familiarize yourself with basic lye soapmaking and the additional procedures taken to make hot process. You'll be more ready to tackle this method if you've gained facility with the others.
The addition of the sugar and alcohol alters the way the molecules crystallize, creating a clear appearance. You may not always get clear soap — it may often be cloudy or translucent, but it will always be unique and beautiful. The soap is perfectly good to use even if it is cloudy.
Although you cannot easily melt and pour this kind of soap, you can cut it into pieces and use it as chunks and other fancy shape details in cold-process soaping. You can do this kind of fancy work with glycerin soap base, but if you make your own lye-based translucent soap, you may have better luck with the chunks staying in place due to the similarity of the makeup of the soap.
Transparent soap made through the hot-process method lets you control the ingredients, just as you do with opaque soap. It can be a tricky process, with a lot of trial and error, but the benefits are great, not the least of which is the pride you feel when you say, “Yes, I did make that!”
Transparent Soap Equipment
You will need the usual lye soap equipment, plus hot-process equipment, plus a few things especially for transparent soap. You can use the same molds you've been using. Of course, the safety precautions apply.
If you don't already have a fire extinguisher in your soapmaking area, you must get one before making transparent soap with alcohol. Make sure it is charged and within reach. You shouldn't have to find out where it is when you desperately need it.
If you have a gas range, don't use it. Get a two-burner buffet range. It is not worth the potential danger and worry to use alcohol over an open flame.
Transparent Soap Ingredients
To make transparent soap, you'll make a simple syrup of water and sugar and add it with the alcohol. To help ensure the transparency of the finished product, the base oils need to maintain clarity. Highly saturated oils that look opaque, for example, if used in high amounts will make the soap less transparent. Excess fats, so desirable in other lye soap, will make this soap cloudy, so you cannot superfat the way you do with other methods.
For this reason, transparent soap recipes use a high level of lubricating castor oil and limit the coconut oil. Castor oil is a major component in transparent soapmaking. It is transparent, provides lather, and is lubricating to the skin. You need some coconut oil for cleansing and lather. Palm oil is for the production of stearin, which makes the bar hard.
Transparent Soap/Frost Soap
Yields approximately 4 to 8 ounces of frost soap and 16 to 20 ounces of transparent soap
6.5 ounces coconut oil
6.5 ounces palm oil
6.5 ounces castor oil
6.25 ounces water
3 ounces lye
10 ounces (plus 2 ounces more if needed for clarity)
90-percent ethanol (190 proof vodka)
2 ounces water
5 ounces sugar
Color, fragrances, and other additives as desired
Place the coconut oil, palm oil, and castor oil in a 3.5-quart slow cooker, turn on high, and put on the cover. If you have a stainless steel easy-read thermometer, you can place it in the pot and lift it out of the melted, warmed oils to check the temperature.
When oils are up to 135° to 140°F, turn the slow cooker down to low. Keep the oils at 130° to 140°F.
Place the water in a heatproof container. Sprinkle the lye into the water and stir until lye is dissolved.
When the lye solution cools to about 135° to 140°F, pour it slowly into the oils. Stir with a silicone spatula to blend completely.
Wearing an oven mitt over your rubber glove, tilt the slow cooker enough so the head of your hand blender is completely submerged. (This prevents air getting whipped into the mixture.)
Blend in short pulses, alternately stirring and scraping the sides with the spatula, until the mix has come to medium trace. (This will happen quite quickly.)
Put the lid on the slow cooker. (It is important not to open the lid unless you have to. You want to prevent evaporation.)
Let the traced soap batter sit in the slow cooker on low with the cover on for 2 hours or until it is neutral. Stir it once every 30 minutes while it neutralizes to keep the soap batter cooking evenly. The mass may get puffy, but the stirring releases the built-up air.
It will get gel-like around the edges after the first 30 minutes. Using the silicone spatula, blend the soap together completely. After another 30 minutes, stir well again, being sure to incorporate any bits that are getting dry on the edges. These need to incorporate back into the mass so that they don't show up as flecks later.
Cook for another 30 minutes. Stir well, incorporating the dry bits as before.
After another 30 minutes, stir well and remove a very small sample of soap with the spatula. Scrape the sample onto a double thickness of paper towel or a paper plate. This will provide you with a disposable testing site. Drip a drop of the phenolphthalein on the sample. If it turns vibrant pink, the soap needs more cooking. If it is barely pink to clear, proceed to the next step.
When you've determined the soap is neutral, give it another good stir, scraping the sides of the slow cooker and incorporating all the soap into a homogeneous mass.
Pour the alcohol into the soap in a medium stream. Stir well with a wooden spoon to break as many lumps as you can. (The alcohol will evaporate and the fumes are strong, so stand back! You need to be sure that there are no open flames when doing this. Alcohol fumes are highly flammable.)
The room-temperature alcohol will harden the soap quite a bit. Break it up with a wooden spoon or a potato masher. Drizzle the alcohol and soap mixture on the sides of the slow cooker to help dissolve any dried soap that is sticking to the sides.
Use the hand blender to further break down the chunks. The slow cooker will still be hot, so be sure to wear an oven mitt as you tip the crock to the side to make a deep enough amount of soap to submerge the head of the blender. You don't need to completely dissolve all the tiny pieces as they'll dissolve while the alcohol-and-soap mixture cooks.
After working it with the hand blender, the soap will look opaque and a little foamy. As the soap cooks, it will liquefy into a clear yellow-to-amber liquid. Try to work quickly so that as little alcohol evaporates as possible.
Turn the slow cooker to high, put on the cover, and heat it until it foams up. It will happen quickly, and as long as the lid fits well and is heavy, the boiling mixture will stay inside. You can place a large, folded bath towel on top to help weigh down the lid and absorb any escaping mixture.
Check the contents after 15 minutes. There will be some foam and chunky bits on the top. Move the foam aside and spoon some of the clear liquid into a small glass. If there are still little chunks of soap, hand blend again until they're all gone.
Turn off the heat and let the soap sit with the cover off for about 10 minutes. This will cause some of the foam to reincorporate into the clear soap without foaming back up.
Don't try to incorporate all the foam, as it may cloud the soap. You'll use the foam to make pretty soap with a frosty appearance. Just knock down as much as you can with a good spritz of alcohol.
Prepare the sugar solution by boiling the water in a saucepan on the stove, then adding the sugar. (It will become a very thick syrup.) Stir well, bring back up to a boil and boil for about 30 seconds. Add the hot sugar syrup to the soap mix in the slow cooker, pouring it right from the pan and stirring well the entire time.
There will be a considerable layer of bubbles, similar to “scum” when you make jam and jelly. Let this sit on the surface, gently stirring it in. It will dissolve. Scoop out the stubborn bits.
Scoop the foam off the surface of the clear soap. This is the “frost soap” part. Put it in a mixing cup (a heatproof glass 4-cup measure works perfectly), and work it well with a wooden spoon to get out as much of the air as you can before putting it in the molds. Add color, fragrance, and other additives as desired. Pack into molds or form into spheres and set aside.
There will be clear, golden fluid soap under the layer of foam. Remove some of this and place it on a clear plastic lid, like one from a margarine tub. Tip the lid to the side to make a little puddle at the edge of the lid. Put the soap-testing lid in the freezer for 10 minutes.
Put the lid on the pot while you're waiting to minimize the layer of hardened soap that forms at the surface. You can gently submerge this “skin” to keep remelting it back into the mass.
If the soap sample is clear when you take it from the freezer, proceed to the next step. If the soap sample isn't clear at this time, add another ½ ounce of alcohol. Test again. If it still isn't clear, add another ½ ounce. Test again. Even if it still isn't clear, proceed anyway — you'll have pretty soap with a degree of translucency.
After the soap is as clear as it is going to get, pour the soap through a strainer into a 4 cup heatproof glass measuring cup. Let the soap cool to 140°F. (This temperature is relatively kind to essential oils, if you're using them, and it will not cause most fragrance oils to cloud the soap.)
You can color and fragrance the entire amount the same and pour into a mold or molds. Or you can pour into individual mixing cups and color and fragrance each one differently.
As soon as the soap is poured, get it into the freezer. (Make room in the freezer before you get this far. The more quickly the soap cools, the better, for rapid cooling helps with transparency.) When the soap is firm and cool but not frozen, remove it from the freezer.
It is harder to keep the temperatures at the right place with a batch under four pounds, so there is no one-pound recipe given for transparent soap. The amounts of ingredients must be precise, and that is more difficult to do in such a small recipe. If you decide to increase the following recipe, you must use a proportionately larger slow cooker.
Sometimes no matter what you do, your attempt at transparent soap turns out cloudy or opaque. Although disappointing — since the entire idea of going through all this is to have beautifully transparent soap — don't be discouraged. If your soap isn't transparent, it is still beautiful and extremely useful.