The Beginner's Guide to Making CP Soap 

If you’re new to making cold process soap, then this is the place to start.

Equipment

To get started you will need some basic equipment:

Safety Equipment
  • Safety Equipment
    • Safety Goggles (A must to protect your eyes from the caustic lye and raw soap mixture).
    • Rubber Gloves (Another must to protect your skin from the caustic lye and raw soap mixture).
    • Paper mask (To protect your face and to reduce hazard from the lye fumes).
  • A scale – One that measures in grams, ounces or pounds (to the 1/10th place)
  • A few mixing containers – Either pyrex or stainless steel.
  • A spatula (or two)
  • A Mixing Spoon and Wisk
  • A Stainless steel pot – To melt your oils in.
  • An accurate, quick reading thermometer.
  • A few small measuring cups or beakers to hold your fragrances, colors or other additives.
  • Paper Towels, Rags or Dish Cloths to clean up spills.
  • An apron (optional but good for protecting your clothing)
  • A stick blender (optional but speeds up the process)
  • A Soap Mold

Ingredients

You will also need some basic ingredients (picture of ingredients):

  • Sodium Hydroxide (NaOH)
  • Distilled Water
  • Oils or Fats (You need to decide on your oil/fat mixture and run it through a lye calculator prior to starting)
  • Fragrance (either Fragrance Oil or Essential Oil – optional)
  • Pigment or other color additive (optional)

Make Your Recipe

Select your oils

To get started, decide on the oils that you will use to make your soap and the size of the batch. We recommend starting with a few simple oils and making no more than 1-3 pounds of soap in a batch, as you are learning.

Calculate the amount of lye and water

Take the amounts of your oils and run them through an online lye calculator. The lye calculator will tell you the possible ranges of lye to use. For beginning soapmaking, we recommend a lye discount of 5%1 and a 33% lye solution2 (twice the amount of water as the amount of lye.

Print out the results from the lye calculator and have it available to you as you start to make your soap.

Prepare the space

Select an area to work in which you will not be interrupted. You will need a flat surface or countertop, access to a heat source and eventually a sink. Remember that lye is caustic, so make sure small children or animals are not going to access your in-process soap.

We recommend choosing an area that is not sensitive to caustic materials when you decide where to make your soap. A stainless steel counter-top is best; other wise cover or protect the surface you are woking on. Do not make soap in your kitchen on that beautiful granite or quartz counter top! All it will take is one spill or splatter and you’ll be sorry you did.

Prepare yourself

Once you have your location, your equipment, your recipe and you are ready to go, be sure to put on that apron, goggles and gloves. Lye and raw soap can be painful if it lands on exposed skin or even worse, in an eye. Soapmaking is supposed to be fun, not end in an trip to the emergency room!

Prepare your ingredients

The soapmaking process consists of several different phases which actually take place over the course of 1 - 3 days.

Make the lye solution

In order to mix the lye with the oils, the lye must be dissolved in water. Measure out your water and sodium hydroxide so that you can make your lye solution. The lye solution will naturally heat up and will need to cool down before you can use it for soapmaking.

Caution!

Be very careful handing and mixing the lye. It is extremely caustic and can cause severe damage if it gets and stays on the skin.
If you get lye on your skin, flush will cool water immediately.

Follow these steps to make your lye solution:

Slowly add the lye to the water
  1. Using your scale, take a heavy plastic, heat-resistant glass or stainless steel container and place it on the scale – thus giving you the weight of the container. (Use the same unit of measurement you used in the lye calculator – either ounces or grams)
  2. Once you have the weight of the empty container, press the "tare" button on your scale to return it to zero. You are now ready to measure your distilled water.
  3. SLOWLY pour the distilled water into the container on the scale until you reach your desired weight. Be accurate!
  4. Remove your water container from the scale and return the scale to zero (usually by hitting the “tare” button again)
  5. Place your sodium hydroxide container on the scale. Follow the same process you did for the water container, measuring the weight of the empty container first, then pressing "tare", to bring it back to zero.
  6. Next, take your sodium hydroxide and SLOWLY pour it into the container on the scale (You are wearing your gloves, right?) until you reach your desired weight.
  7. Next, in a well ventilated area, SLOWLY pour the sodium hydroxide into the water. NOTE: Never pour water into sodium hydroxide!
  8. Use your spatula to make sure the solution is well mixed. Avoid breathing the fumes as much as possible.
  9. The solution will heat up. Set aside and wait for it to cool to between 95°F and 105°F3.

Prepare your other ingredients and materials

While the lye solution is cooling you can prepare your other ingredients and materials.

Choose your fragrance (optional), color additives (optional) and/or any additives **(link) that you will be incorporating. Get them out and set aside so they're ready.

During this time, also prepare your mold.

Mix and melt your oils

Next you need to combine your oils/fats in the soap pot. Depending on how many oils/fats you have, you may need to repeat these steps several times:

  1. Place an appropriately sized container for the first oil/fat on the scale and weigh it. Press the "tare" button to return the scale to zero.
  2. Slowly either scoop (for solid oils/fats) or pour your oil into the container to the desired weight.
  3. Pour the measured oil/fat into your stainless steel soap pot
  4. Repeat #1 - #3 for each oil/fat you have in your recipe.

If your recipe contains solid oils/fats, you will need to melt them. Place your pot on a heat source (either a stove or a hot plate) and turn it on to medium heat. Do not leave your pot unattended! You do not want to overheat or burn the oils, only gently melt them. Stirring gently usually helps to break up the big pieces of solid oils and speed along the process.

Once the oils mixture is melted, turn off your burner to allow the oils to cool down between 95°F and 105°F4.

Measure your other ingredients

While you are waiting for the oils and lye solution to cool, you can measure out your other ingredients. If you are not using fragrance, color or other additives, skip this step.

For each fragrance, color additive or other additive, place an appropriately sized container on the scale and weigh it. Press the "tare" button to return the scale to zero. Slowly pour/place your ingredient into the container until you reach the desired amount. Set aside.

NOTE: As a general rule of thumb, don't use more than about 0.6 ounces of fragrance per 1 pound of oil/fat in your recipe.

Make the soap

Use your digital thermometer to tell when your oil and lye solution have reached the desired temperature. Once they are ready, you can start the final phase (before the dishes, that is).

Make sure you have everything ready at your work station - your mold, oils, lye solution, and fragrance and/or other additives. Plug in your stick blender and make sure you have your safety equipment on (put it back on, you know you took it off when you were waiting for things to cool down).

Begin by pouring your lye solution slowly into your fats/oils and stirring with your whisk. Once all of the lye solution is in, scrape sides and stir with the spatula until everything is initially blended.

If you are using a stick blender, completely submerge it in the solution. If you used a big pot, you may have to tilt it to submerge the blender. Using short bursts, start to blend the solution, trying to get the edges and the bottom, completely mixing everything. Scrape down sides with the spatula to be sure no under mixed lye or oil remains.

SLOWLY pour the lye solution into the oils
Use a stick blender to mix the soap

If you're not using a stick blender, then just keep mixing and mixing by hand. It will work fine, but will take a while longer.

The solution will start to thicken as it saponifies (combines to become soap). Once it reaches "trace", you are ready to pour it into the soap mold. "Trace" is when the soap mixture is still thin enough to pour off a spoon, but thick enough to leave a "trace" on the top of the pot as it falls back in. It's about like cake batter.

Add any fragrance, color and/or other additives, using whisk or stick blender to incorporate fully.4

Trace
Pour the soap into your mold

Slowly pour the wet soap into the soap mold. Be sure to get all of the soap out of the pot, and get it into all of the corners of the mold. Once the pot is empty and your mold is filled, lightly tap the mold on the surface of your work station to make sure the soap is set and to release any trapped air. You can clean the edges of the soap mold if you wish, but it is not necessary.

Wrap or cover the mold with a heavy blanket or towel to contain the head and allow it to rest and cure for 12-24 hours. It will get quite warm and then cool down. That is the saponification process taking place. Once the soap is fully cooled, you can unmold it.

Depending on your oils and water content, the soap may be soft when unmolded. Allow soap to rest until it is hardened up a bit (1 - 3 days) and then cut it as desired. Set aside in a cool area with good circulation for 4 - 6 weeks until the bars are fully hard.

Congratulations! You just made your first batch of cold process soap!


Notes:

1 There is a wide range of possible lye discount or superfat percentage. For beginning soapmakers, a lye discount of about 5% will create a gentle bar of soap and eliminates any possibility of gettting a lye-heavy bar because of variations in the saponification levels of the oils used.

2 A 33% solution is the easiest solution to work with. Soap can be made with a higher percentage solution (50% - equal parts water and lye) but it is more difficult and is considered and advanced technique. Likewise, soap can be made with a lower percentage solution (25% - three times the amount of water than of lye), but it takes a long time to make and is generally reserved tricky multi-color soaps that need plenty of time during which they can be worked into the mold.

3 Soap can be made at temperatures below 95°F or above 105°F but its a little more tricky. For beginners, 95°F to 105°F is recommended temperature for both the lye solution and the oils.

4 Some fragrance oils, essential oils and other additives (usually with alcohol in them) can cause the soap to thicken very quickly (sieze) when they are added. If you haven't verified that your additives won't affect the soap, be watchful for any sudden changes in the soap mixture and be ready to act quickly if necessary.

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