In the mold hot process soap is a variation of hot process soap. In making a typical hot process soap the oil and lye are combined, mixed till trace and then cooked on the stove or in the oven until thick and slushy-like, then combined with additives, fragrances, essential oils and the like. The last step to the usual hot process method is to place it in the mold and let it cool. At the end of 24 hrs or so the soap is ready to use and cut into useable pieces.
In contrast, in the mold hot process soap or ITMHP is soap that is cooked (baked) in a mold in the oven. In this way this method mimics the cold process method without the weeks of waiting for the soap to cure and be free from lye. Another benefit of this type of method is that the soap has a smoother, less grainy texture than soap that is cooked on top of the stove or cooked in the oven and then poured into a mold.
Why use In the Mold Hot Process method? Well, if you like cold process soap but do not like waiting for weeks for the soap the cure and be free from lye, then this method is right for you. In a mere 24-48 hours the soap will be ready and though this way to make soap sounds a lot like regular hot process in the oven soap, yet the advantages to this method is that the soap has a much more refined and smoother appearance. All in all, this method to making soap is preferred by folks who just donít like waiting for soap to cure or soap that has a primitive and lumpy appearance like regular hot process soap.
Most recipes for cold process soaps can be adjusted for this method. Below are some important points to consider before making in the mold hot process soap:
1. The mold has to be sturdy enough to withstand the constant heat of the oven without conducting too much heat. Thus, I advise using a mold that is 100% wood, not particle board or plywood. Inspect the joints to make sure they do not have glue that will come apart under the heat of the oven. Check with the manufacturer also to make sure that any glue used will not give off any toxic fumes such as formaldehyde, which is present in some wood substitute products.
2. The ingredients used and especially fragrances and essential oils will need to be ones with flashpoints that are higher than the temperature of the oven. The typical oven temperature for this method is anywhere from 175-180 Degrees Fahrenheit.
3. The oven has to be protected from any seepage from the mixture by lining it with tinfoil or placing a baking sheet under the mold.
4. Keeping the temperature under 200 degrees is very important. What we are trying to do is mimic the saponification process of cold process soap. The difference here is that we are extending this process a bit by cooking it for 2 hours and then leaving it in the warmed oven another 12 or more hours to set. Typically, cold process soap heats up and saponifies at temperatures between 175 - 190 Degrees Fahrenheit. At the end of which there is some lye left over in the soap so that it has to be cured for 3-6 weeks to get rid of that lye.
***Most regular cold process soap recipes can be finished in this method.
For full directions for making cold process soap see article How To Make Cold Process Soap Follow directions 1-9, then follow directions for In The Mold Hot Process Soap listed below:
As in making cold process soap, combine the lye and oils and mix with a sturdy wire whisk or stick blender till it reaches trace. Next, pour the traced soap into a sturdy, lined wooden mold or one deemed safe by a mold manufacturer for oven use. I like to use sturdy plastic for lining the mold going into the oven.
Cut the plastic lining for mold large enough so that there is extra to fold and cover the soap to prevent it from drying out and forming s crust. Place the covered soap in a preheated oven 175-190 Degrees Fahrenheit for 2 hour, after which you turn off the oven and leave the soap in the oven for another 12 hours or more to solidify. The soap is ready to cut once it is firm enough to cut.
Test a piece of soap before using for lye. I like to break a piece off and use it to wash my hands. If there is no tingling, the soap is fine to use. Unmold and cut into slices.
But if there is tingling, slice soap into bars and leave to cure in a cool location for 3-4 weeks. At the end of which it is adviseable to test for lye.
Tongue test for lye
Some folks use the tongue test to test if the soap is ready to use. I do not use this method because to me the soap tastes horrible and I cannot distinguish the awful taste of the soap from the sting of lye if it is present! But for those hardy souls who are not deterred by this, break off a piece of soap and taste it with the tip of your tonge. If it burns and is tingly, then there is lye in the soap. If the taste is just awful without the burning, then there is no lye present and you can test the soap further by using a small piece to wash your hands. If there is not tingling, then the soap is ready to use. Unmold and cut into slices.