Homemade laundry detergent with baking soda is simple to make: mix washing soda, baking soda, Borax, and grated soap for a cheap, effective powder, or combine them with liquid Castile soap for a gel that costs pennies per load.
Store-bought detergent is expensive, and the bottles are full of water. Making your own takes about 20 minutes, uses ingredients you probably already own, and costs around $10–15 for a year’s supply. The trick is knowing which white powder does what—baking soda and washing soda are chemically distinct, and swapping them ruins the recipe. This guide covers the two best methods (powder and liquid), the exact ratios, and the common mistakes that can wreck a batch or a load of clothes.
What Is the Difference Between Baking Soda and Washing Soda?
This is the most important distinction to get right. Baking soda is sodium bicarbonate; washing soda is sodium carbonate. Washing soda (also sold as Super Washing Soda) is the heavy lifter—it softens water and lifts dirt. Baking soda is a mild abrasive and deodorizer. If you use only baking soda, your homemade detergent will barely clean anything. You can turn baking soda into washing soda by spreading 500g on a baking sheet and baking it at 350°F for 30 minutes, stirring halfway through. That heat drives off carbon dioxide and water, leaving you with sodium carbonate.
The Powder Recipe: Simple, Long-Lasting, and Cheap
Powder detergent is the most popular method because it’s shelf-stable, easy to store, and takes five minutes to mix.
Ingredients (for a full batch)
- 2 cups washing soda (Arm & Hammer Super Washing Soda)
- 2 cups baking soda
- 2 cups Borax
- 1 bar (5 oz) Fels-Naptha or Castile soap, finely grated
Steps
- Grate the soap bar with a box grater or pulse it in a food processor until it resembles coarse meal. Finer powder dissolves better in cold water.
- In a large bowl, combine the washing soda, baking soda, Borax, and grated soap. Stir or whisk until the color is uniform and no white streaks remain.
- Transfer to an airtight container. A glass jar with a tight lid works best—moisture makes the powder clump.
How much to use per load
Use 1 tablespoon for a high-efficiency (HE) washer, 2 tablespoons for a standard top-loader. If you have especially hard water, add an extra teaspoon of washing soda to boost softening.
If you are looking to compare the best pre-made commercial options alongside this DIY approach, check out our detailed roundup of top-rated baking soda laundry detergents on the market.
Homemade Laundry Detergent: Powder vs. Liquid
Both recipes work in any washer, but they behave differently. This table shows the trade-offs so you can pick the right one for your routine.
| Feature | Powder | Liquid |
|---|---|---|
| Shelf life | 6+ months in an airtight container | 2–4 weeks; can separate or gel |
| Cold water performance | Must be finely ground or pre-dissolved in hot water | Works fine in cold water as-is |
| Prep time | 5 minutes | 30 minutes |
| Cost per load | ~3–5 cents | ~5–8 cents |
| Best for | Bulk batches, long-term storage, heavy soil | Pre-treating stains, cold water washes |
| Stain removal | Good (use a paste of powder + water) | Better (apply liquid directly) |
| Container needed | Airtight jar or bin | Heat-safe gallon jar or jug |
The Liquid Recipe: Better for Cold Water and Pre-Treating
Liquid detergent takes longer to make but dissolves instantly in any water temperature and works well as a stain pre-treater.
Ingredients
- 1 cup Borax
- 1 cup washing soda
- 1 cup liquid Castile soap (e.g., Dr. Bronner’s)
- 50 drops essential oil (lavender, lemon, or tea tree work well)
- 15 cups water, divided (6 cups boiling, 9 cups room-temperature)
Steps
- Boil 6 cups of water in a large pot. Remove from heat. Do not boil the soap or Borax mixture directly—foam will make a mess and ruin the consistency.
- Add the Borax and washing soda to the hot water. Stir until fully dissolved. The water will look cloudy but clear as the solids dissolve.
- Add 9 cups of room-temperature water. Stir gently.
- Slowly pour in the liquid Castile soap while stirring. Do not whip or agitate violently—you want minimal foam.
- Let the mixture cool for 5–10 minutes. Do not add essential oils until the liquid has cooled; heat causes the oils to evaporate.
- Stir in the essential oil. Pour into a clean, heat-safe gallon jar or container. If using a plastic container, make sure the mixture is fully cool first.
How much per load
Use 1/4 cup for an HE machine, 1/2 cup for a standard washer. Shake the jar gently before each use because the mixture can separate or gel slightly as it cools—this is normal.
Common Mistakes That Ruin Homemade Laundry Detergent
These five errors cause most failures. Avoid them and your first batch will be your last store-bought purchase.
- Using baking soda instead of washing soda. Baking soda alone won’t clean effectively. You need washing soda (or make it from baking soda by baking it).
- Grating soap too coarsely. Large flakes don’t dissolve in cold water. A food processor makes a fine, flour-like powder that dissolves instantly.
- Adding essential oil while the liquid is hot. The oil evaporates immediately. Wait until the mixture is cool.
- Boiling the soap for liquid detergent. This creates foam that overflows and ruins the gel texture. Always heat the water alone, then dissolve powders off the heat.
- Adding vinegar or baking soda to the wash cycle. Mixing these with your homemade detergent or with commercial detergent reduces cleaning power. Add vinegar only to the rinse cycle as a fabric softener.
Cost and Ingredient Checklist for a Year’s Supply
| Ingredient | Amount for 2 full canisters | Approx. cost |
|---|---|---|
| Fels-Naptha soap (3 bars) | 3 x 5 oz bars | $6–8 |
| Arm & Hammer Super Washing Soda | 1 large box (55 oz) | $4–5 |
| Borax | 1 large box (76 oz) | $4–5 |
| Baking soda | 1 large box (64 oz) | $2–3 |
| Essential oil (optional) | Small bottle | $4–8 |
Total for a year’s supply: $10–15 using bulk ingredients. That beats the $200–300 you’d spend on name-brand liquid detergent over the same period.
FAQs
Can I use just baking soda and water for laundry?
Baking soda alone is a mild deodorizer and stain lifter, but it lacks the water-softening alkalinity of washing soda. It will not remove heavy soil or body oils effectively as a standalone detergent. Use it for odors and light freshening, but pair it with washing soda for real cleaning power.
Does homemade laundry detergent damage HE washing machines?
No—homemade powder and liquid detergents are safe for high-efficiency (HE) washers when you use the correct amount: 1 tablespoon for powder or 1/4 cup for liquid. The key is making sure the soap is finely grated so it dissolves completely. Undissolved residue can build up in HE machines, so always use fine powder.
How do I store homemade laundry detergent so it doesn’t clump?
Store powder detergent in an airtight container in a dry space—a cabinet away from steam or laundry moisture. A glass jar with a rubber gasket works perfectly. If you live in a humid climate, add a silica gel packet to the container. Liquid detergent keeps best in a heat-safe glass jar with a lid, shaken before each use.
Can I use this detergent on baby clothes or sensitive skin?
Yes, but with a condition. Use a bar soap that is fragrance-free and dye-free, such as plain Castile soap, and skip the essential oils. The basic ingredients—washing soda, Borax, and soap—are generally well-tolerated. However, do a patch test on one garment first if you have concerns about skin sensitivity.
Why did my liquid detergent turn into a gel or separate?
Separation or gelling is normal in homemade liquid detergents, especially as they cool. This happens because the Castile soap and mineral salts interact differently at different temperatures. Simply shake the jar vigorously before each use—the mixture will re-combine and work just fine. Gelled detergent is still effective.
References & Sources
- The Frugal Homemaker. “Homemade Laundry Detergent.” Provides cost breakdown and volume-based recipes.
- Arm & Hammer. “DIY Detergent.” Official manufacturer guidance on using washing soda.
- Live Simply. “Homemade Liquid Laundry Soap.” Detailed liquid recipe and safety notes.