Hey everyone! Homebrewer here. If you used Refracto on iOS, you know it was a great refractometer calculator for tracking fermentation — until it disappeared from the App Store. Since the original code was open source (BSD-3, credit to Michael Schmidt), I rebuilt it for the web with the original correction formulas (Bonham, Novotný, Terrill) and added some things I always wanted:
- Recipes with BJCP style targets (OG/FG/ABV ranges shown as you log readings)
- Fermentation log with a gravity + temperature chart (Brewfather-style)
- Manual entries for past readings, wort correction factor, °Brix ⇄ SG
- Data backup/restore (everything stays on your device — no cloud, no account)
It works offline after the first visit: open the link on your phone and use “Add to Home Screen” — it behaves like a native app from then on.
refracto.netlify.app
Free, no ads, no tracking. I don’t make anything from this — I built it because I needed it myself. If you spot a mistake or have suggestions, let me know and I’ll fix it!