How to make it
- 1Dissolve salt in warm water first
This step is what gives the soap its thickness. Pour warm distilled water into a bowl and add kosher salt. Stir for 1–2 minutes until the salt is completely dissolved. Do not skip this — undissolved salt makes the soap gritty.
- 2Mix vinegar, Sal Suds, and lemon juice separately
In a second bowl, combine the white vinegar, Sal Suds, and fresh lemon juice. Stir gently — Sal Suds foams easily, so use slow, gentle circular motions rather than whisking.
- 3Combine the two mixtures slowly
Pour the Sal Suds mixture into the salt water, not the other way around. Stir slowly until combined. The mixture will thicken noticeably as the salt interacts with the soap.
- 4Add essential oil and stir
Add 10–15 drops of lemon essential oil and stir gently to distribute. More oil means stronger scent — adjust to your preference.
- 5Transfer and leave to fully thicken
Pour the soap into your container using a funnel. Leave it undisturbed for 30 minutes — it thickens further as it cools. It will not be as thick as commercial dish soap, but it cleans equally well.
Castile soap (like Dr. Bronner's liquid soap) reacts with the minerals in hard water and leaves a white, filmy residue on dishes. Sal Suds is a synthetic-free but non-soap detergent that does not have this problem — it rinses clean in any water hardness. It is the better choice for dish soap specifically.
Surfaces guide
- Use orange or grapefruit essential oil for a different fresh citrus scent
- Add 1 tsp glycerine for a more moisturising version that is gentler on hands
- Increase Sal Suds to ¾ cup for a stronger formula suited to heavily greasy pots
- Use lime juice instead of lemon juice for a slightly different, brighter scent
- Add 5 drops of tea tree oil for extra antimicrobial action