Salted Out Scraps

Beginning Weight of Scraps: 113 oz
Lye for superfat: 0.8 oz NaOH
Salt: 28 oz
Water: 113 oz

Order of Operations​

1. Preparation & Hydration

• Grind the scraps: The smaller the pieces, the faster they will dissolve.
• Heat the water: Bring your 113 oz of water to a simmer in a large stainless steel pot. Do not use aluminum.
• Dissolve: Add the scraps slowly. Stir constantly (you can use your high-shear mixer on a low setting here) until the mixture is a smooth, homogenous, thick liquid.

2. The "Booster" Saponification

• Lye Solution: Dissolve the 0.8 oz of NaOH into a small amount of additional distilled water (approx. 2-3 oz).
• Add to Pot: Pour the lye solution into the boiling soap slurry.
• Boil: Maintain a low boil for 20–30 minutes. This ensures that the lye finds and reacts with the 5% free oils that were previously suspended in the scraps. The mixture may become very thick or "heavy."

3. The "Graining" (Salting Out)

• Add Salt: Begin adding your 28 oz of salt in increments (about 5 oz at a time).
• Observe the Break: As you stir in the salt, the soap will begin to lose its smooth texture and look "curdy" or grainy. You will see a clear separation between the white soap curds and the dark, murky liquid (the "spent lye" containing the glycerin, color, and salt).
• Test: Once the soap floats to the top in a thick, cake-like layer and the liquid underneath is watery (not syrupy), you have reached the "grain" point.

4. Separation & Cooling

• Turn off heat: Let the pot sit undisturbed for at least 4–6 hours (preferably overnight).
• Remove the Soap: The soap will solidify into a hard crust on top. Lift this "curd" out.
• Discard the Liquid: The liquid underneath (the sub-lye) contains the impurities you want to remove. Discard it safely down a drain with plenty of water.

5. Optional Purity Wash
If the soap still smells of the old fragrance or looks tinted:

• Redissolve the curd in a fresh batch of boiling water (no new lye needed).
• Add salt again to grain it out a second time. This "washing" of the curd is how industrial soap makers achieve 99% purity.

6. Final Wash

• Add about 10% fresh distilled water to the curds in a pot and heat on low. Allow the fresh water to pull residual salt out to the curd