Pink Grapefruit Soap Recipe (Cold Process)

I love making homemade soap—a staple in my DIY routine. This grapefruit soap recipe is one I return to again and again. The citrus scent is super uplifting, and the formulation of the bar leaves your skin feeling soft and nourished. It’s perfect for brightening your day, whether it is part of your morning shower or a little pick-me-up after a long day. It’s surprisingly simple, even if you’re new to soap-making.

A close-up of pale pink homemade grapefruit soap bars with visible flecks of grapefruit zest, set on a rustic blue wooden surface.

Grapefruit Soap Recipe

Create your own nourishing grapefruit soap with this simple recipe, blending natural oils and citrus zest for a refreshing, homemade skincare product. Perfect for those who appreciate a touch of nature's zest in their daily routine.
Prep Time 45 minutes
Curing 1 day
Total Time 1 day 45 minutes

Equipment

Ingredients 

  • 4.27 ounces lye
  • 7.5 ounces water
  • 2.5 ounces grapefruit juice
  • 11 ounces olive oil
  • 11 ounces coconut oil
  • 6 ounces shea butter
  • 2 ounces castor oil
  • 2 teaspoons grated grapefruit zest
  • 3 tablespoons of grapefruit essential oil

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Instructions 

  • Prepare the lye solution.  Wear your gloves, goggles, and mask, and work in a well-ventilated area. Then, using a digital scale, measure the lye and water separately in non-reactive containers. Next, slowly add the lye to the water (never the other way around) and stir until completely dissolved. The solution will heat up due to a chemical reaction, so be cautious of the heat and fumes. Set the lye solution aside in a safe place to cool to about 90-100°F.
  • Melt and measure the oils:  Measure all oils (olive, coconut, shea butter, and castor oil) into a pot or heat-safe container. Then, gently melt the oils over medium-low heat until fully combined. Once melted, remove from heat and allow the oil mixture to cool to 90-100°F.
    A pink spatula stirring a pot filled with a golden yellow melted soap mixture, indicating the mixing stage in soap making.
  • Add the grapefruit juice.  Make sure the lye solution and oils are at similar temperatures (within 10 degrees of each other), around 90-100°F. Then, carefully add the grapefruit juice to the lye solution. Stir gently. The solution may turn orange—this is completely normal.
    A side-by-side image of a pot on the left with yellowish soap mixture being poured into it, and on the right, a stick blender immersed in the soap mixture with a few drops of red colorant visible.
  • Blend the lye solution with the oils.  Pour the lye solution into the melted oils slowly. Use a stick blender to mix until the soap mixture reaches trace—a pudding-like consistency where the mixture leaves a trail when the blender is lifted.
    An overhead view of a clear measuring cup filled with a clear liquid set on a patterned cloth, with a pot containing a yellowish mixture in the background, ready for soap making.
  • Add the color, fragrance, and zest.  At trace, stir in the grapefruit zest and essential oil by hand. If using colorants, blend them with a small amount of oil before adding them for a smooth distribution. Pour the soap batter into your prepared mold immediately, smoothing the surface as needed.
    Hands measuring out colored pigments and adding drops of red colorant into a jar of clear liquid, likely for coloring soap.
  • Gel phase.  Preheat your oven to its lowest setting (around 170°F or “warm”). Turn off the oven and place your soap mold inside for about 1 hour. This step encourages the gel phase, which deepens the soap’s color and texture. Leave the soap in the oven to set for 24 hours, undisturbed.
  • Unmold and cure.  Carefully remove the soap from the mold and cut it into bars. Then, allow the bars to cure in a well-ventilated space for at least 2 weeks. For a harder, longer-lasting bar, extend curing to 4 weeks.
    A hand cutting a large bar of homemade soap in half with a knife on a wooden board.

Notes

Before you start, gather all your tools, ingredients, and safety gear.  Soap-making can go fast once you begin, so organizing will help you save time and avoid mistakes.
Even if you’ve made soap before, wearing gloves, goggles, and long sleeves is important.  Just a little splash of lye solution can cause serious burns, so always put safety first.
Old or poorly stored lye can lose its strength and affect your soap.  Use fresh, good-quality lye and keep it in a sealed container in a dry spot.
Strain the grapefruit juice to eliminate any pulp, as this can make the texture uneven.  Use a fine grater and skip the white pith for the zest since it’s bitter and won’t give you the fresh scent you want.
Tap water might have minerals that could mess with your soap, so it’s best to use distilled water for a cleaner and more consistent result.
Silicone molds are flexible and make it easier to remove your soap without damaging the bars.  If you’re using a wooden mold, line it with freezer paper to help take the soap out more easily.
Want to try something new?  You can add some natural mica powder for color or swap out the essential oil for another citrus option, like lemon or lime.  Just keep the total amounts of oil and liquid the same.
If experimenting with new ingredients, make a small test batch first.  This way, you can make sure everything works well together and save time and materials if you need to make changes.

In our home, the quest for the perfect homemade soap never ends. We’ve experimented with countless scents and ingredients, but this one is our new favorite. There’s something about the fragrance that we love. This recipe is super cleansing and perfect for the shower or use as a hand soap next to the kitchen sink.

Try this cold process soap specifically designed for the shower to create durable and perfect soaps for daily routines.

A row of homemade pale pink grapefruit soap bars lined up on a blue wooden surface with white flowers in the background.

The secret to beautifully vibrant soap is the addition of fresh grapefruit juice and zest, which give it that gorgeous citrusy boost. I love this recipe because it’s beginner-friendly but feels like a special treat whenever you use it.

Pink Grapefruit Soap Tips

  • Know Your Temperatures: Temperature matters! If your oils and lye solution are too hot or cold, they might not combine properly. Invest in two thermometers so you can monitor them simultaneously.
  • Handle Lye Safely: Always add lye to water (never water to lye) to avoid a dangerous reaction. Stir slowly, and work in a well-ventilated area to avoid inhaling fumes. If you’re new to working with lye, this lye safety guide is a must-read to help you handle it confidently and safely.
  • Blend to the Right Trace: Beginners often worry about over- or under-blending. Trace is when the mixture thickens slightly, like pudding. If you’re unsure, stop blending, lift the stick blender, and check for a trail that sits on the surface.
  • Avoid Overheating Your Oils: If your oils get too hot, they’ll take longer to cool and can speed up trace too quickly when combined with the lye solution. Melt them over low heat and monitor the temperature closely.
  • Add Essential Oils at the Right Time: Always add essential oils after reaching trace. Adding them too early can cause the scent to dissipate due to the heat generated during the process.
  • Avoid Air Bubbles: Keep a stick blender fully submerged to avoid introducing air bubbles into your soap batter. Pulse the blender instead of running it continuously.
  • Test for pH Before Use: Once your soap is cured, check its pH with a simple test strip to ensure it’s skin-safe. A pH level between 7 and 10 is ideal.
  • Use Insulation Wisely: Cover your soap mold with a towel or place it in an insulated box to encourage the gel phase. However, if your environment is already warm, skip this step to prevent overheating or cracking.

Watch the Video

Key Ingredients and Tools

Here are some important tools and ingredients to help you make your soap successfully.

A close-up of pale pink homemade grapefruit soap bars with visible flecks of grapefruit zest, set on a rustic blue wooden surface.
  • Lye (Sodium Hydroxide): This is essential for all cold process soaps. It works with oils to create soap through a process called saponification. You can find lye at specialty soap-making stores or online. Be careful when handling it, as it can be very harsh.
  • Grapefruit Juice: Fresh grapefruit juice gives the soap a natural citrus flavor and helps create a lovely orange color when mixed with lye. Strain it well to remove any pulp affecting the soap’s consistency. You can also use lemon or lime juice instead for a similar citrus taste, but the color might look a little different.
  • Grapefruit Essential Oil: This oil adds a bright and refreshing scent to the soap. You can find it in the essential oils section of natural food stores or online. If unavailable, you can use another citrus oil, like lemon or lime.
  • Olive Oil: This oil is important in many soaps because it moisturizes the skin. Use pure, extra-virgin olive oil for the best outcome. It’s usually available in most grocery stores, but avoid blends containing other oils. Sunflower or sweet almond oil can replace olive oil but might slightly change the soap’s texture.
  • Castor Oil: This oil helps create a bubbly and rich lather in the soap. It’s available at pharmacies, natural health stores, or online. Make sure it’s cold-pressed and pure for soap-making. Avocado oil can work instead of castor oil, but it may change how bubbly the soap is.
  • Shea Butter: This adds a creamy texture to the soap and helps moisturize the skin. You can find shea butter in natural food stores, craft shops, or online. Use unrefined shea butter for the best quality. You can swap it for mango butter or cocoa butter, which moisturizes well.
  • Silicone Soap Mold: Silicone molds are flexible, making it easier to take the soap out without breaking it. They come in many shapes and sizes and can be found in craft stores or online. You can use a lined loaf pan if you don’t have one.
  • Stick Blender: This tool is important for quickly mixing the lye solution and oils. A stick blender makes the process much faster than stirring by hand. If you don’t have one, you can stir manually, but it will take longer.

These tools and ingredients are crucial for making this recipe work. With them, you’re ready to create some beautiful and nourishing soap!

Usage Suggestions

Use this soap with a matching grapefruit sugar scrub, a soft cotton hand towel, and a soothing herbal tea sachet for the perfect self-care set.

Troubleshooting and Help

Can I use bottled grapefruit juice instead of fresh?

Fresh is best for this recipe because it doesn’t contain added preservatives or sugars that might interfere with soap-making. If you’re in a pinch, make sure the bottled juice is 100% pure grapefruit with no additives.

Why does the lye solution turn orange when I add the grapefruit juice?

That’s totally normal! The natural acids and sugars in the juice react with the lye and create the orange color. It won’t affect the final soap, so no need to worry.

My soap didn’t trace—what went wrong?

It could be a few things. The oils and lye solution might not have been at the right temperature, or you might not have blended long enough. Stick with it—sometimes, it just takes a little extra blending!

How long does the soap really need to cure?

The minimum is 2 weeks to make sure it’s safe and firm enough to use, but if you can wait 4 weeks, your soap will be harder and longer lasting. Patience pays off here! If you enjoyed making this cold-process soap, why not try a new method? Hot-process soap-making is a fun and creative alternative that’s quicker to cure and offers a rustic finish.

What should I do if my soap batter thickens too fast?

This can happen if you over-blend or if the temperatures are too high. Work quickly to pour it into the mold—it’ll still make great soap, even if it’s not as smooth.

My soap cracked during the gel phase—what happened?

This usually happens if the soap overheats. Try insulating it less next time or skipping the oven phase if your workspace is already warm. Soap can still be used—it’s just a cosmetic issue.

Can I add color to this soap?

Absolutely! You can use natural colorants like mica powder or infused oils to create a pop of color. Just make sure any additives are skin-safe and compatible with soap-making. If you loved making this grapefruit soap, why not try these summer soap recipes.

Storing Homemade Soap

Once your soap is cut into bars and fully cured, proper storage is key to keeping it fresh and long-lasting.

Curing Phase:

During the curing process (2-4 weeks), place the soap bars on a wire rack or parchment paper in a cool, dry, and well-ventilated area. Make sure the bars aren’t touching to allow air circulation on all sides.

After Curing:

Store your cured soap bars in an airtight container or a cool place. Keep them away from direct sunlight and moisture, which can cause the soap to sweat or degrade over time.

Freezing:

Freezing is not recommended for cold-process soap. When thawing, it can draw moisture to the surface, leading to a sticky texture and reduced quality. Instead, focus on proper curing and dry storage to extend shelf life. There’s just no need for it.

Long-Term Storage:

If you need to store soap for months, wrap each bar in wax paper or in a breathable container like a cardboard box. This prevents dust and moisture buildup while allowing the soap to “breathe.”

This soap might just become your new favorite DIY project. It’s simple enough for beginners but impressive enough to gift or display in your bathroom. This recipe has never disappointed me, and I’m confident it’ll become a go-to in your homemade skincare routine. Don’t forget to make an extra batch to share—your friends and family will love it!

A top view of four homemade pale pink grapefruit soap bars stacked with a slight overlap, alongside delicate white flowers on a blue wooden background.
picture of smiling female

By Katie Shaw

Katie lives in Virginia with her husband, three daughters, a chocolate lab, and over thirty chickens. She loves creating simple tutorials for sourdough, bread, and soap. Her recipes, articles, and YouTube videos reach millions of people per year.

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Recipe Rating




5 Comments

  1. 5 stars
    Thank you Katie for making such amazing and helpful recipes and videos. You have taught and helped so many of us. I have learned to make some of your bread recipes, dinners, jams, and soap. Sincerely, Cheryl

    Reply

  2. I have strained water that whole kefir limes have been boiled in. Could this be used instead of grapefruit juice?

    Reply