How to Make Pumpkin Purée Cold Process Soap

For this batch, I'm making a spiced pumpkin cold process soap using real pumpkin purée! I'm keeping the design pretty simple and letting the pumpkin do its thing. I'm also sharing how I adjusted my water amount to account for the purée and why fragrance oil selection matters when it comes to discoloration.

New to cold process soapmaking? Before trying this recipe, check out my Beginner's Guide to Making Cold Process Soap and Lye Safety Guide to get familiar with the process and important safety precautions.

Ingredients

Lye Solution

• 8.96 oz (254.01 g) Distilled Water

• 6.38 oz (180.95 g) Sodium Hydroxide (NaOH)

Oils & Butters

• 26.22 oz (743.32 g) Olive Oil | 57%

• 11.50 oz (326.02 g) Coconut Oil (76°) | 25%

• 4.60 oz (130.41 g) Shea Butter | 10%

• 3.68 oz (104.33 g) Castor Oil | 8%

Additives

• 4 oz (113.40 g) Pumpkin Purée

• 1.44 oz (40.77 g) Nature's Garden Spiced Pumpkin Latte Fragrance Oil

Recipe Details

• Total Oil Weight: 46 oz (1,304.08 g)

• Superfat: 5%

• Original Water Amount: 12.96 oz

• Distilled Water Used: 8.96 oz

• Pumpkin Purée Added: 4 oz

Supplies Used

• Digital Scale

• Heat-Safe Containers

• Stainless Steel or Silicone Mixing Utensils

• Immersion Blender

• Soap Mold

• Thermometer

• Safety Goggles and Chemical-Resistant Gloves

• 91% Isopropyl Alcohol (Optional

Directions

1. Gather your supplies and put on your safety equipment, including gloves, goggles, and long sleeves. Work in a well-ventilated area away from children and pets.

2. Carefully add the sodium hydroxide to the distilled water and stir until completely dissolved. Always add lye to water, never water to lye. Set the solution aside to cool.

3. Weigh your oils and butters. Melt the coconut oil and shea butter, then combine them with the liquid oils.

4. Once your oils and lye solution have reached appropriate soapmaking temperatures, carefully pour the lye solution into your oils.

5. Use an immersion blender to bring the mixture to a light emulsion.

6. Add the Spiced Pumpkin Latte fragrance oil and mix until incorporated.

7. Once the soap reaches a light trace, add 4 oz of pumpkin purée and blend until evenly incorporated.

8. Continue mixing until the soap reaches a medium trace, then pour it into your prepared mold.

9. If desired, create a simple textured top using a spoon or spatula. Allow the soap to thicken enough to hold the texture.

10. Lightly spray the top with 91% isopropyl alcohol to help reduce soda ash, if desired.

11. Allow the soap to sit for approximately 48–72 hours before unmolding and cutting, or until firm enough to handle.

12. Cut the soap into bars and allow them to cure in a cool, dry, well-ventilated area for approximately 4–6 weeks before use, checking that the bars are properly cured.

Using Pumpkin Purée in Cold Process Soap

When adding fruit or vegetable purées to cold process soap, it's important to consider the additional water they contribute to the recipe.

For this batch, my original recipe called for 12.96 oz of distilled water. Since I was adding 4 oz of pumpkin purée, I reduced the distilled water to 8.96 oz. Keep in mind that pumpkin purée isn't entirely water. It also contains natural sugars, carbohydrates, and other solids, so this is a practical adjustment rather than an exact water-for-water replacement.

If you've never worked with purées before, I recommend starting with approximately 1 oz of purée per pound of oils and testing how your recipe behaves. I've made this particular recipe before, so I was comfortable using a little more.

Maker Tip: Fragrance Oil & Discoloration Fragrance oils containing vanillin can cause cold process soap to discolor, often turning it shades of tan or brown. Generally, the higher the vanillin content, the greater the potential for discoloration. Since pumpkin purée can naturally contribute to color changes, I wanted to avoid choosing a fragrance that might make my soap even darker. Always check your fragrance supplier's vanillin information and soap testing notes when planning your colors and designs.

Notes

• I used store-bought pumpkin purée instead of making my own. Make sure you're using plain pumpkin purée, not sweetened pumpkin pie filling.

• This soap was a little softer, so I planned to give it 48–72 hours before unmolding and cutting.

• Fruit and vegetable purées can affect how a soap batch behaves, so keep an eye on temperature, trace, and any changes during curing.

Watch the Tutorial

Watch the full video to see how I made this pumpkin purée soap, including the mixing, fragrance addition, pouring, and cutting process.

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Free Soap Maker's Toolkit

If you make cold process soap, I've got a free Soap Maker's Toolkit that includes batch logs, curing cards, a soap design planner, and a batch cost calculator to help you keep track of your recipes and costs.

Soap Maker's Toolkit

Safety Note: This recipe involves sodium hydroxide (lye), which is caustic and can cause serious burns. Always wear appropriate protective equipment, use lye-safe containers, and follow proper soapmaking procedures. Recalculate the lye amount if you change the oils or batch size. Follow the fragrance supplier's current IFRA limits for bar soap.

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