Add your oils and their weights, choose NaOH for a solid bar or KOH for liquid soap, and set your superfat. This works out the lye and water from real saponification (SAP) values — the same chemistry Alchemis runs inside your recipe.
Add each oil or fat and its weight in grams. Pick "Other (enter SAP)" to type a SAP value straight from your supplier sheet.
Add at least one oil with a weight to see the lye and water.
These figures are advisory. Always double-check against a second lye calculator before you mix — lye is caustic and gets hot. Wear gloves and eye protection, add lye to water (never the reverse), and work in a ventilated space.
SAP values are typical published references; the same oil varies between suppliers, so verify against your own sheet. The Alchemis engine does this inside your recipe — with cost per bar, inventory deduction, and the full IFRA and allergen compliance check alongside.
See also: soap fragrance & IFRA limit checker →
New to Alchemis? See soap-maker features →
The lye math lives inside your recipe — with superfat, cost per bar, stock deduction, and the full IFRA and allergen check. For soap and five other crafts. Free forever for hobbyists.