Everything in Soap Studio
A complete toolkit for recipe formulation, batch management, and soapmaking chemistry — on Mac, iPad, and iPhone.
Accurate lye calculations, every time
The calculation engine is Soap Studio's foundation. Every lye weight is verified decimal-place accurate against SoapCalc and SoapmakingFriend. The maths is transparent — you can see exactly how each figure is derived.
- NaOH, KOH, or mixed-alkali (dual-lye) recipes
- Three input modes: percentage of oils, direct weight entry, or total oil weight
- Superfat and lye purity adjustments
- Vinegar and chelator calculations
- Sugar handling (dissolved in lye water, added to batch weight)
- Masterbatch solution calculations
- Three water modes: lye:water ratio, lye concentration %, or water as % of oils
229 oils, butters, and waxes
A comprehensive built-in ingredient library with full fatty acid profiles, SAP values, and densities for 229 oils, butters, and waxes. The complete soap quality index suite is calculated for every recipe.
- Full fatty acid profiles for every ingredient
- Soap quality indices: Hardness, Cleansing, Conditioning, Bubbly, Creamy, Longevity, Stability, INS, Iodine
- Add and save your own custom ingredients
- Oil substitution suggestions
The best cut plan for your mould
Enter your mould dimensions and target bar weight. Soap Studio works out the optimal cut plan — how many loaves, how many bars per loaf — and draws a cutting diagram. It uses a physically correct soap-batter density model and enforces a minimum weight guarantee: bars are never proposed lighter than your target.
- Box and pipe mould support
- Asymmetric weight tolerance — bars are never lighter than target
- Cutting diagram with loaf and bar cut orientations
- Single-loaf mode for home soapers with a hand cutter
- Per-mould overrides for target weight, bar thickness, and loaf width
IFRA safety checks built in
Add fragrances to your recipe with usage rates. Soap Studio checks your fragrance load against IFRA Category 9 limits (leave-on skin products, which includes soap), displaying both your oils-basis percentage and the finished-product-basis figure that IFRA limits are published on — so you're comparing like with like.
- Usage rate tracking per fragrance
- IFRA Category 9 limit checking
- Dual-basis display: oils % and finished-product %
- Store and reuse your fragrance library
Cure-time estimates that make sense
A cure model estimates how long your soap needs before it's ready to use, taking into account the oil profile, bar dimensions, water content, additives, and environmental factors. Cure-date reminders can be added directly to your calendar.
- Cure speed based on your oil profile (high-oleic oils cure slowly; saturated fats cure faster)
- Bar geometry — thinner bars lose moisture faster and cure sooner
- Water content, additives, and environmental adjustments
- Calendar reminder integration (EventKit)
A lab notebook, not a tax form
Log every batch with the details that matter to you — temperatures, dates, notes, photos, actual bars cut, and costs. The recipe is snapshot-stored at the time of the batch, so your history is preserved even if you later change or delete the recipe.
- Manufacture and cure dates
- Photos
- Actual bars cut vs planned (re-bases per-bar cost automatically)
- Batch cost and cost per bar
- Notes — free-form, no mandatory fields
- Recipe snapshot — batch history survives recipe edits
Know what your soap actually costs
Track ingredient costs per batch, cost per bar, sell price, and profit. The pricing model is sell-price primary — enter what you want to charge, and the profit follows. Optional; never gets in the way if you don't use it.
- Per-ingredient cost tracking
- Cost per bar (actual vs planned bar count)
- Sell-price primary, profit derived
- Currency symbol configurable in Settings
Mac, iPad, and iPhone — one app
Soap Studio is a universal app. Your recipes and batches sync across all your Apple devices via iCloud. It works fully offline — no signal needed in the kitchen, shed, or workshop.
- macOS, iPadOS, and iOS
- iCloud sync across all devices
- Fully offline — no internet connection required
- No account, no login, no cloud service dependency
- Free to download