What is a water discount?
Short answer
Using less water than the usual 33–38% of oil weight. The book's recipes mostly use 26–27%.
Explanation
A water discount speeds trace, leaves less water to evaporate, and gives a harder bar sooner, so you can unmold in 24–48 hours. It's especially useful in slow olive-heavy recipes. Very high lye concentrations (around 33%) speed trace dramatically and are recommended only for experienced makers. The hot process recipe uses a full 38% water.
What to do
- If a water-discounted soap is rock-hard in the mold, warm the mold briefly in warm water to release it.
Source: The Big Book of Homemade Soap — Curing Times for Different Soap Formulations