Homemade Laundry Soap: Complete Guide for Homeowners

Commercial laundry detergent costs $0.15-$0.40 per load, which adds up to $100-$200 per year for the average American household doing 8 loads per week. Homemade laundry soap slashes that cost to roughly $0.02-$0.05 per load using three simple ingredients you can buy at any grocery store. Beyond the savings, making your own lets you control exactly what touches your clothes and skin, which matters if you deal with allergies, eczema, or chemical sensitivities.

Basic Powder Recipe

This is the simplest and most popular homemade laundry soap formula. It takes about 15 minutes to make and produces enough for roughly 100 loads.

• 1 bar of Fels-Naptha soap (or Zote, Ivory, or Dr. Bronner’s castile bar) — finely grated
• 1 cup washing soda (Arm and Hammer Super Washing Soda, not baking soda)
• 1 cup borax (20 Mule Team Borax)

1. Grate the bar soap using a cheese grater or food processor. The finer the grate, the better it dissolves in water
2. Mix the grated soap, washing soda, and borax in a large bowl until evenly combined
3. Store in an airtight container. Use 1-2 tablespoons per load

Total ingredient cost: roughly $5-$7 for 100+ loads, or about $0.05-$0.07 per load. All three ingredients are available in the laundry aisle of most supermarkets and big box stores.

Liquid Recipe

Some people prefer liquid soap because it dissolves instantly and works better in cold water. This recipe makes about 2 gallons.

1. Grate 1/3 of a Fels-Naptha bar into a saucepan with 6 cups of water
2. Heat on medium-low, stirring until the soap fully dissolves (about 10-15 minutes)
3. Add 1/2 cup washing soda and 1/2 cup borax. Stir until completely dissolved
4. Pour the mixture into a large bucket or container. Add 4 cups of hot water and stir
5. Add enough cold water to make 2 gallons total. Stir well
6. Let it sit overnight. The mixture will gel or thicken. Stir or shake before each use

Use 1/2 cup per load. The liquid version costs roughly the same per load as the powder. It can separate or develop a lumpy texture over time, which is normal. Just shake the container before pouring. Adding 10-15 drops of essential oil (lavender or tea tree are popular choices) gives it a pleasant scent without synthetic fragrances.

Understanding the Ingredients

Each ingredient in homemade laundry soap serves a specific cleaning function.

• Bar soap (Fels-Naptha, Zote, etc.): The primary surfactant that lifts dirt and stains from fabric. Fels-Naptha is specifically formulated for laundry and has been used for over 100 years. It handles grease and ground-in soil effectively
• Washing soda (sodium carbonate): A water softener and cleaning booster. It raises the pH of the wash water, which helps the soap work more effectively and prevents mineral deposits from hard water from dulling fabrics
• Borax (sodium borate): A natural mineral that boosts cleaning power, whitens whites, and deodorizes. It also inhibits mold and mildew growth in the washing machine

Some recipes add OxiClean (sodium percarbonate) as a fourth ingredient for extra stain-fighting power. Use 1/2 cup per batch for the powder recipe. This is particularly helpful if you regularly wash heavily stained work clothes or children’s clothing.

Does Homemade Soap Work in HE Machines

Yes, with an important caveat. Homemade laundry soap produces very low suds, which makes it compatible with high-efficiency washers that require low-suds detergent. However, the soap-based formula can leave residue in HE machines over time if the soap does not fully rinse in the reduced water volume.

To minimize residue in HE machines, grate the bar soap as finely as possible (a food processor works best), use warm or hot water settings when possible to help the soap dissolve, and run the machine’s self-clean cycle monthly. If you notice a film on dark clothes or a waxy buildup inside the drum, reduce the amount of soap per load or switch to the liquid version, which dissolves more completely.

Homemade Soap vs Store-Bought Detergent

Honest comparison requires acknowledging that homemade soap has limitations. Commercial detergents contain enzymes (protease, amylase, lipase) that break down specific stain types at a molecular level. Homemade soap lacks these enzymes and relies on mechanical agitation and alkaline pH to clean. On everyday soil and light stains, the difference is negligible. On set-in stains like blood, grass, and red wine, commercial detergent with enzymes outperforms homemade soap noticeably.

For most households, homemade soap handles 80-90% of laundry loads perfectly well. Keep a small bottle of commercial stain-fighting detergent or an enzyme-based stain pretreater on hand for the tough loads, and use homemade soap for everything else. This hybrid approach saves the most money while maintaining cleaning effectiveness.

Common Mistakes to Avoid

Several errors can undermine your results with homemade soap.

• Using baking soda instead of washing soda: Baking soda (sodium bicarbonate) is much weaker than washing soda (sodium carbonate). They are different products with different cleaning power. Using baking soda results in soap that barely cleans
• Not grating the soap fine enough: Coarse chunks do not dissolve in cold or warm water, leaving waxy residue on clothes
• Using too much per load: More is not better. Excess soap residue dulls colors and stiffens fabrics. Start with 1 tablespoon for the powder and increase only if needed
• Skipping the vinegar rinse: Adding 1/2 cup of white vinegar to the rinse cycle helps remove any soap residue and naturally softens fabrics
• Expecting it to work on everything: Pre-treat tough stains with a commercial stain remover before washing with homemade soap

Is It Worth Making Your Own

The math clearly favors homemade soap. At $0.03-$0.05 per load versus $0.15-$0.40 for commercial detergent, a family doing 8 loads per week saves $50-$150 per year. The initial batch takes 15-20 minutes to make and lasts 2-3 months. If you value knowing every ingredient that touches your family’s clothes, or you have skin sensitivities that commercial fragrances and dyes aggravate, homemade laundry soap is absolutely worth the minimal effort.