# Soap Lye Calculator - Trace — Batch Tracker & Cure Journal > Batch Tracker & Cure Journal (iPhone/iPad app by Karol Jaworski.) - Source: https://appshunter.io/ios/app/soap-lye-calculator-trace/id6759573509 (this page in markdown: same URL + `.md`) - Developer: [Karol Jaworski](https://appshunter.io/developer/1799974477) - Category: Lifestyle, Utilities - Price: Free with in-app purchases - Age rating: 4+ - Requires: iOS 17 · 10 MB - Languages: American English - Released: 2026-05-07 - Data updated: 2026-08-20 - User reviews in markdown: https://appshunter.io/ios/app/soap-lye-calculator-trace/id6759573509/reviews.md ## What is Soap Lye Calculator? Calculate lye, log every batch, and never lose a great soap recipe. Trace is the precision toolkit for cold process and hot process soapmakers. Whether you're crafting your first lye soap or refining a proven formula, Trace puts accurate calculations, a complete soap log, and organized recipes all in one place. LYE CALCULATOR - Calculate NaOH or KOH amounts for any oil blend - 40+ oils with accurate SAP values built in - Adjust superfat percentage and water-to-lye ratio - See predicted soap properties before you pour BATCH LOGGING - Log every cold process or hot process batch - Visual cure progress tracker with days remaining - Capture batch ratings, notes, and evaluations - Know exactly when each batch is ready to use RECIPE LIBRARY - Save and refine your custom soap formulas - See predicted soap properties for every soap recipe - Filter by status: testing, proven, or production - Access a curated starter collection CURE TRACKING - Automatic cure countdown for every batch - Ready badge when full cure time is complete - Visual progress rings showing cure percentage - Never sell or use under-cured soap again SOAP PROPERTIES - Predict hardness, cleansing, conditioning, and lather - Bubbly vs. creamy lather balance at a glance - Iodine and INS values for stability - Property bars for each recipe and batch TRACE PRO - UNLOCK YOUR FULL SOAP STUDIO Trace Pro gives serious soapmakers the complete toolkit: - Unlimited soap recipes and formulas - Unlimited entries in your soap log - All 7 soap property predictions - Full starter recipe library (30+ proven recipes) - Property prediction charts before you pour Free tier includes 5 saved recipes and 10 batch logs - perfect for getting started. Whether you make lye soap for personal use, for gifts, or to sell at farmers markets, Trace keeps your formulations precise, your soap log organized, and your best recipes saved forever. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Trace Pro | $4.99 | per month | | Trace Pro | $39.99 | per year | | Trace Pro | $39.99 | per year | ## Version history (last 5 releases) ### 1.40 — 2026-08-19 Batch Evaluations: record pH, lather, conditioning, and hardness scores after cure. Tap "Evaluate" on any batch. Batch Editing: fix names, dates, and process details at any time. Tap "Edit" on any batch. Weigh-In Tracking: log weekly weights to track moisture loss during cure. 30+ Starter Recipes: 20 new formulas - avocado, hemp, babassu, mango butter, tallow, and more. Recipe Ratings: star-rate your recipes directly from the detail view. ### 1.39 — 2026-08-11 Important lye accuracy correction, plus full oil breakdowns so a batch can actually be repeated. PLEASE READ IF YOU LOGGED A BATCH BEFORE THIS UPDATE When you logged a batch, Trace worked out the lye using one average value for every oil instead of each oil's own SAP value. For most common recipes that estimate was low, which makes a soft, oily bar. For recipes built mainly on shea, cocoa or mango butter, or on soft oils like grapeseed, jojoba, beeswax or lanolin, it could go the other way and suggest more lye than the oils can saponify. That leaves free lye in the bar. This only affected the lye figure shown on a logged batch. The Calculator has always used each oil's own SAP value and was correct. If you made soap from a batch you logged in Trace, and it was heavy in butters or soft oils, please check the bar before using it. A zap test is the quickest way. If it zaps, do not use it on skin. It can usually be rebatched. We are sorry. This should have been right from the first version. WHAT IS FIXED - Batch lye and water now use each oil's exact SAP value, through the same calculator the Calculator tab uses. There is now one calculation in the app, not two. - If a blend does not total 100 percent, Trace records no lye figure rather than a guess. WHAT IS NEW - Batches now save and show every oil you used, with its weight and percentage, and the total. Previously the oils were never saved at all, which is why a saved batch could not be repeated. - You can enter oils when logging a batch, with live gram amounts as you type. - Saved recipes now take a batch size, then show each oil's weight plus the lye and water for that size. Presets for 500 g, 1 kg, 2 lb and 3 lb, and your last size is remembered. - Batch cards show total oil weight. Recipe cards show how many oils are in the blend. - Batches logged before this update will say no oil breakdown was recorded, rather than showing a blank. Thank you to the soapmaker who wrote in about missing weights. It led us to the calculation problem as well. ### 1.38 — 2026-07-24 This update fixes the most important bug we've had: recipes and batches now save correctly and appear in your lists, and they stay saved after closing the app. If you tried to save before and lost your work, we're truly sorry. Everything you save from this version on is safe — and syncs to iCloud automatically. Also in this update: - Clear message explaining why Save is unavailable (e.g., oils must total 100%) - Improved Restore Purchases and account deletion Thank you to the customers who reported this. ### 1.37 — 2026-07-19 Two important fixes based on customer feedback: • Recipe names, batch notes, and text you type into any field are now clearly visible in both light and dark mode • A "Done" button now appears above the number keypad so you can dismiss the keyboard and get back to saving Thank you for the reports — please keep them coming. ### 1.36 — 2026-07-15 Welcome to Trace 1.0! Your complete soap studio - lye calculator, batch logger, cure tracker, and recipe library all in one app. Perfect for cold process and hot process soapmakers at every level. ## More apps by Karol Jaworski - [HairRush - End Hair Loss](https://appshunter.io/ios/app/hairrush-end-hair-loss/id6743035238) - [Sparky - Daily Couple Fun](https://appshunter.io/ios/app/sparky-daily-couple-fun/id6744193208) - [REMbank - Deposit Better Sleep](https://appshunter.io/ios/app/rembank-deposit-better-sleep/id6745431668) - [Couple Duel - Fun Task Tracker](https://appshunter.io/ios/app/couple-duel-fun-task-tracker/id6745432130) - [Snugli - Baby Tracker & Care](https://appshunter.io/ios/app/snugli-baby-tracker-and-care/id6747285231) - [TellieTales: Bedtime Stories](https://appshunter.io/ios/app/tellietales-bedtime-stories/id6747285384) All apps by Karol Jaworski: https://appshunter.io/developer/1799974477 ## Related topics [soap lye calculator](https://appshunter.io/ios/topics/soap-lye-calculator) · [soap journal](https://appshunter.io/ios/topics/soap-journal) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-20.*