Laundry butter is just soap without any extra fat. It’s a wonderful cleanser for your hand-wash items, can be scented however you like, and leaves your fabrics fragrant, clean, and soft. Interestingly, there is very little difference between the recipe for laundry soap and the recipe for a foaming bath butter. Simply put, laundry butter differs from foaming bath butter in the fat content — referred to in soap lingo as the superfat. While laundry butter has no superfat oils, foaming bath butter provides nutrient-rich emollience in the form of several luxury oils. In this article, you will learn how to make hand-washable laundry soap, and with the same recipe for laundry soap, you will learn how to make a foaming bath butter with 20 percent superfat content — very rich, indeed.

First things first: please note that this soap should not be used for machine washing. Doing so may void your warranty. This soap should also never be used for washing diapers, and may cause the necessity of stripping if used for an extended period of time.  

To make the butter base, we start off with a 100 percent coconut oil base recipe, superfatted to 0-1 percent — exactly enough fat to react with the lye, and no more. If you are unfamiliar with how to make coconut oil soap, please see the article on basic soap making skills. Learning how to make laundry soap is the same as the bath butter, except for the addition of four ounces of luxury oils to the mix.

Recipe — Laundry Butter

Makes approximately 3 pounds

• 32 oz. coconut oil
• 5.85 oz. sodium hydroxide
• 12 oz. water
• .75 oz. fragrance, optional
• 32 oz. water (added later)

First things first — don your protective eyewear and gloves. Measure 12 ounces of water into a heat-safe, nonreactive container. Set aside. Weigh 5.85 ounces of sodium hydroxide and add to water. Stir until fully dissolved. Allow to cool to room temperature, between 70-90 degrees Fahrenheit. Meanwhile, melt coconut oil and weigh 32 ounces of oil into a nonreactive bowl. Allow the coconut oil to cool to room temperature as well. Pour the lye solution into the coconut oil and use a stick blender to blend the soap to medium trace. Pour into mold and allow to saponify for 24-48 hours.

When soap is cooled and hardened, slice into pieces and shred with a food processor or hand grater. Add shredded soap along with 32 ounces of water to a slow cooker set on Low and allow the soap shreds to fully melt. Remove from heat, pour into a large bowl and allow the soap to cool for 30 minutes.

Using a hand mixer or stand mixer with whisk attachment, whip the soap mixture until white, fluffy and thick. Add fragrance oil, if using, and mix thoroughly. Portion into containers for use. To use, scoop out two tablespoons of butter per gallon of warm water and dissolve into water before washing clothes.

Next, we will learn how to transform laundry butter into an emollient, gentle foaming bath butter.

Foaming Bath Butter

Makes about 3 pounds

• 32 oz. coconut oil
• 5.85 oz. sodium hydroxide
• 12 oz. water
• 1 oz. EACH — castor oil, cocoa butter, olive oil and shea butter (or use butters/oils of your preference)
• .75-1.5 oz. fragrance, optional
• 32 oz. water (added later)

To make foaming bath butter, follow the same procedure as for laundry butter including whipping with the stand mixer. When whipped, add the extra oils slowly and continue whipping to incorporate well. Last, add the soap scents and mix well once again. Portion into containers for use. To use, scoop out a small portion with hands or spoon and smooth directly onto the body, hold under the faucet for a moisturizing bath, or add to a bath puff for lots of rich, gentle lather.

Both laundry butter and foaming bath butter make excellent homemade gifts, as well as useful luxuries to make for home use. With one simple process, you can create both of these products and dispense them into glass jars for gifting. Will you make laundry butter or foaming bath butter at home? Share your experiences with us!

Ask the Expert

Do you have a soapmaking question? You’re not alone! Check here to see if your question has already been answered. And, if not, use our chat feature to contact our experts!

Does the recipe for foaming bath butter also require curing time and how long is its expected shelf life? Thank you. – Ja

No, it does not require curing time. The soap is fully saponified, and because it is not being used in bar form on the skin, there is no need to wait for the soap to become milder and for the water to dry out. The foaming bath butter has extra oil added to make it milder and more gentle to the skin immediately. – Melanie