Sourdough is flour, water, salt and time. None of that needs an account, a subscription or a server keeping track of your starter. OpenSourdough is built on that idea.
What it does
Most recipes give you times written for someone else’s kitchen, and most disappointing loaves come from following them too closely. The app turns a recipe into a plan for your day. It times each step to your dough temperature, moves the rest of the day when you finish a step early or late, and tells you what the dough should look like at each stage.
It sizes the recipe to the pot you actually own, counts the flour and water inside your levain so the numbers add up, learns how fast your starter peaks, and keeps a journal so each bake teaches you something for the next.
What “open” means here
- No sign-up. Open it and bake.
- Your data stays yours. Bakes, feeds and notes are saved in your browser on your device. There is no OpenSourdough server holding them, so clearing your browser data clears your journal. Save a backup file from the Journal tab and you can restore it on any device.
- It works offline. Once it has loaded, it runs with no signal.
- Everything is free to read. The recipes, the starter guide and the troubleshooting are all on this site. You do not need the app to use them.
- Open to everyone, not open source. The app’s code is not published.
How it stays free
There are no ads yet. If the website shows some later, to pay for hosting and the time it takes to keep improving it, they will be clearly labelled, and the privacy page will say what they can and cannot see before they appear. The app will not show ads at all: nothing should get between you and a timer when your hands are covered in dough.
Where to find us
OpenSourdough is on Instagram, TikTok, YouTube, Facebook, Pinterest and X as @opensourdough, and on Bluesky as @opensourdough.com. These are the only official accounts.
How the facts are checked
Anything about food safety or the science of a starter links to where it comes from: the USDA and CDC for safety, published research for the microbiology, and King Arthur Baking's test kitchen for baking practice. Each source is read before it is linked, and if no source backs a claim, the claim changes. That check has already corrected advice here, like how long tap water needs to stand and how hot a loaf has to be inside.
If you find something wrong, tell us. A source helps.
About the photos
The photographs on this site are made with AI and are for illustration. The recipes follow standard baking practice, every fact links its source, and they are the same ones the app runs on.