Homemade laundry soap is an inexpensive way to wash everyday clothing, towels, and household linens for only pennies per load. This classic liquid recipe combines 1/3 bar of finely grated Fels-Naptha, 1/2 cup washing soda, 1/2 cup 20 Mule Team Borax, and 3 gallons of water to make approximately 60–64 regular loads.
The finished mixture develops into a cloudy, loose gel with a clean laundry-soap scent rather than the dramatic foam of commercial detergent. Active preparation takes about 20–30 minutes, followed by 12–24 hours of resting time so the soap can thicken before you portion it into covered, labeled containers.
Jump to RecipeWhy You’ll Love This Recipe
This homemade laundry soap uses a short list of familiar, budget-friendly ingredients and produces a large batch at once. Three gallons of finished soap can cover roughly 60–64 regular loads, depending on how much you dispense and how large each load is.
The recipe is also easy to customize in practical ways. You can use a half-cup for normal laundry, increase the amount to one cup for heavily soiled clothing, or adjust your approach for hard water without changing the basic formula.
Unlike a dry powder, this version is already mixed with water and can be poured directly into a measuring cup. Its loose gel texture may look different from one batch to the next, but cloudiness and mild separation do not automatically mean the soap has failed.
While you wait for the batch to set, you can plan a cozy kitchen project such as homemade soup recipes for dinner. The same habit of measuring carefully and labeling containers serves both household projects and cooking projects well.
Ingredients You’ll Need
Gather the ingredients before heating anything. Washing soda is sodium carbonate, not baking soda, so check the package carefully when shopping.
- 1/3 bar Fels-Naptha: Finely grate the bar portion, which should weigh about 2 ounces or 57 grams.
- 1/2 cup washing soda: This alkaline powder helps support cleaning in the mixture.
- 1/2 cup 20 Mule Team Borax: Measure it level for consistent batches.
- 3 gallons water: Use about 6 cups for dissolving the soap and reserve the rest for the bucket.
You will also need a large saucepan, a long-handled spoon, a box grater, a clean 3- to 5-gallon bucket, and labeled covered containers for storage. Choose tools that can be washed thoroughly after use, and do not use the saucepan for food again unless it has been cleaned according to the manufacturer’s instructions.
Do not add baking soda or oxygen bleach to this basic recipe unless you are intentionally following a different tested formula. Those ingredients appear in some variations, but they are not part of this classic version.
For another homemade pantry project, you might enjoy this bright cranberry salsa while your laundry soap rests overnight.
How to Make It Step-by-Step
Step 1: Put on a well-ventilated workspace and measure all of the dry ingredients before beginning. Finely grate one-third of the Fels-Naptha bar, aiming for small, thin shreds rather than chunky pieces so the soap melts quickly and leaves fewer flakes.
Step 2: Add the grated soap to a large saucepan with about 6 cups of water. Set the pan over medium-low heat and stir frequently, scraping the bottom and sides as needed, until the soap completely dissolves; keep the heat gentle and do not allow a vigorous boil.
Step 3: Remove the saucepan from the heat once the soap is fully melted. Add the 1/2 cup of washing soda and 1/2 cup of Borax, then stir patiently until the powders disappear into the liquid and no gritty layer remains at the bottom.
Step 4: Carefully pour the hot soap mixture into a clean 3- to 5-gallon bucket. Add the remaining water to reach a total of 3 gallons, then stir thoroughly with a long-handled spoon so the concentrated saucepan mixture disperses evenly.
Step 5: Cover the bucket and let it stand overnight for 12–24 hours. During this resting period, the mixture may become cloudy, separate slightly, or change into a loose gel; these appearances are normal for this recipe.
Step 6: Stir or whisk the finished laundry soap before filling storage containers. Pour it into clean, labeled, covered containers, leaving enough room to shake or stir the soap later if it separates.
Step 7: Measure about 1/2 cup for a regular load. For heavily soiled clothing, use up to 1 cup, and stir or shake the container before dispensing whenever the mixture looks layered.
How Much Laundry Soap Should You Use?
For a typical load, begin with approximately 1/2 cup. This amount is the standard starting point for the 3-gallon batch and helps the finished soap stretch to around 60–64 loads.
Very dirty work clothes, gardening garments, or heavily used towels may need up to 1 cup. Avoid assuming that more soap always means cleaner fabric, because excess product can contribute to residue, especially when rinsing conditions are limited.
High-efficiency washers require special care. Homemade soap can leave residue in some HE machines, so use a low-sudsing amount and check your washer manufacturer’s instructions before making it your regular laundry product.
If your water is hard, many published versions recommend adding a small amount of washing soda rather than simply increasing the soap. Make changes cautiously and monitor your clothing, washer drum, and rinse results over several loads.
Safety, Storage, and Cleanup
Borax and washing soda are alkaline powders, so avoid inhaling them while measuring. Keep children and pets away from the dry ingredients, the hot saucepan, the bucket, and the finished product.
Store the completed laundry soap in labeled, covered containers. A label should identify the contents and clearly state that the mixture is not for drinking or eating, since the soap may resemble a cloudy household liquid.
Do not store the mixture in an unmarked beverage bottle. Keep containers closed when not in use, wipe up drips promptly, and wash measuring cups and utensils after dispensing.
For a pleasant snack-board idea while tackling a laundry day, see this guide to building an ultimate snack board. Keeping household products and edible ingredients in separate, clearly identified areas is always important.
Variations and Helpful Troubleshooting
A commonly published larger-batch variation uses 1 full bar of Fels-Naptha, 1 cup of washing soda, 1 cup of Borax, and approximately 5 gallons of water. That version follows the same general process but is not the quantity used in the recipe card above.
Dry versions are also widely circulated. They commonly combine 1 grated bar of Fels-Naptha with 1 cup of washing soda and 1 cup of Borax, then use 1–2 tablespoons per load; however, the liquid formula here should be measured by the half-cup or cup.
If your batch seems too thick, stir it thoroughly before deciding that something went wrong. If it separates, mix or shake it before every use, and remember that the finished product may remain cloudy rather than becoming perfectly smooth.
If you notice flakes, the original soap shreds may not have been fine enough or fully dissolved. Next time, grate more finely and keep the saucepan over gentle heat while stirring frequently; never solve the issue by boiling the mixture vigorously.
After laundry day, a loaf of homemade buttermilk bread makes a comforting kitchen companion. Just keep all food preparation surfaces, tools, and ingredients completely separate from laundry-soap equipment.
Homemade Laundry Soap for Pennies a Load
Ingredients
Method
- Finely grate 1/3 bar of Fels-Naptha, about 2 ounces. Fine shreds dissolve faster and are less likely to leave visible flakes in the finished soap.
- Place the grated soap in a large saucepan with about 6 cups of water. Warm over medium-low heat, stirring frequently, until every shred has dissolved; do not let the mixture boil vigorously.
- Remove the saucepan from the heat. Stir in the washing soda and Borax until both powders are fully dissolved and the liquid looks evenly mixed.
- Pour the hot mixture into a clean 3- to 5-gallon bucket. Add the remaining water and stir thoroughly with a long-handled spoon.
- Cover the bucket and let the laundry soap stand overnight, or for 12–24 hours. It may become cloudy or thicken into a loose gel, and either result is normal.
- Stir or whisk the finished soap before transferring it to labeled, covered containers. Stir or shake the container before each use if the mixture separates.
Notes
Final Thoughts
This homemade laundry soap is a practical, low-cost formula that turns a small amount of Fels-Naptha, washing soda, and Borax into approximately 3 gallons of usable laundry soap. With about 1/2 cup per regular load, the batch can cover roughly 60–64 loads, making it an appealing option for careful household budgeting.
Give the mixture 12–24 hours to set, expect a loose gel or cloudy appearance, and stir before dispensing. Store it in labeled covered containers, use caution around the alkaline powders, and follow your washer manufacturer’s advice, particularly if you own a high-efficiency machine.
Once the batch is mixed and stored safely, laundry day becomes a simple measuring task. A few minutes of preparation can supply weeks of household cleaning at a very small cost.