• Add the surfactants to your container, weighing each one directly into it and taring the scale between additions.
• Add most of the distilled water and gently stir or swirl to combine, trying not to create too much foam.
• In a separate container, dissolve the salt in a portion of the remaining water. Once fully dissolved, add it to the detergent and stir gently. The mixture will begin to thicken as it incorporates.
• At this point, choose how you want to preserve your detergent. You can either add a broad-spectrum preservative or raise the pH using a small amount of lye solution. (See notes below for more details.)

Option 1: Use a preservative

• Add a broad-spectrum preservative that works within the pH range of your detergent. This recipe is usually around pH 5 before any adjustments (though that can vary), so choose a preservative that works in that range and use it at the recommended rate, typically around 0.5–1% (about 5–10 g for this batch). Mix well, and your detergent is ready to use.

Option 2: Raise the pH (no preservative)

• Instead of using a preservative, you can raise the pH of the detergent to help prevent microbial growth. Add a small amount of lye solution (sodium hydroxide or potassium hydroxide), mixing well and checking the pH as you go, until you reach a pH above around 9. You don’t need much, so it’s best to add it slowly and adjust as needed. Once you’ve reached the desired pH, your detergent is ready to use.
• Once everything is fully combined, your detergent is ready to use.
• Use around 2–3 tablespoons per load, adjusting as needed.