Best Sourdough Starter Apps in 2026: What to Look For

Full disclosure first: we make Boulie, one of the apps in this article. So rather than a ranked list with made-up scores, this is a guide to what actually matters in a sourdough starter app, what several apps say they offer, and where Boulie is a good fit or a poor one.

Everything we say about other apps comes from their own App Store listings or websites, checked on September 14, 2026. We haven’t listed prices, ratings or download numbers, because they change often and vary by country. Check the current listing before you decide.

TL;DR

• Just want reminders? A simple, lightweight tracker will do.
• Want to know when your starter will peak? Look for predictions based on your own feeds and temperature.
• Want recipes, timers and a bake log in one place? Pick an all-in-one app.
• Care about cost structure? Apps range from free to one-time purchases to subscriptions. Decide which you’re comfortable with before you get attached.
• Whatever you choose, the best app is the one you’ll actually log feeds in.

What to look for in a sourdough starter app

1. Fast feed logging

You’ll log a feed once or twice a day on the counter, or once a week from the fridge. If it takes more than a few taps, you’ll stop. The useful details are ratio (1:1:1, 1:5:5…), flour type and temperature, because those are what determine when your starter peaks.

2. Reminders that understand counter vs fridge

A counter starter needs attention every 12–24 hours; a fridge starter about once a week. Reminders that don’t know the difference either nag you daily about a sleeping fridge starter or leave a counter starter hungry. Our feeding schedule guide explains why these two routines are so different.

3. Help knowing when it’s ready

The most common starter question is “is it ready yet?”. Some apps simply record what you tell them. Others try to predict the peak from your feeding history, and a few can look at a photo. If this is what you struggle with, it’s the feature to prioritize. (If you want to learn the signs yourself, start with how to tell when your sourdough starter is ready.)

4. Bake guidance

Recipes, step-by-step instructions, and timers or alarms for stretch and folds, bulk fermentation and baking. Some apps focus on the starter only; others cover the whole bake.

5. Calculators

Hydration, baker’s percentages and feeding amounts come up constantly. An app can include them, but you don’t strictly need one: the free sourdough hydration calculator and starter feeding calculator on this site do the math in a browser.

6. A journal you’ll look back at

Photos of loaves, notes on crumb and flavor, and history of your feeds. This is how you notice what changed between a great bake and a flat one.

7. Privacy and accounts

Do you need to sign up? Where is your data stored? Is anything sent to a server? For a baking app the stakes are low, but it’s worth knowing, and some apps are clearer about it than others.

8. Clear pricing

Free with ads, free with in-app purchases, a one-time unlock, or a subscription. None of these is wrong, but you should know which one you’re getting before you’ve spent two weeks logging feeds.

The three kinds of sourdough apps

Simple feed trackers. Log a feed, get a countdown and a reminder. Fast and low-friction. Good if your starter is healthy and you just forget.

Bake companions. Timers for each stage, recipes, temperature notes and a bake log. Good if you bake often and want structure on bake day.

Smart or AI-assisted apps. Predictions, photo analysis or a chat assistant on top of tracking. Good if you want answers, not just records, as long as the “smart” part is grounded in what’s actually in your jar.

Some sourdough apps worth knowing

These are the features each app highlights in its own listing, as of September 14, 2026. It isn’t a complete list of what each app does, and we haven’t tested every feature.

App	What its listing highlights	Pricing model (per listing)	Account
Sourdough Starter Tracker	Feed logs, status-based reminders (active, refrigerated, dormant), health notes, feeding and hydration calculators, multiple starters	Free with a one-time premium purchase; says “no subscription”	States no account needed
Sourflow	Multi-phase bake timer, temperature logging, bulk fermentation estimate, Live Activity, peak predictions from feeding history, reminders, saving your own formulas	Free with in-app purchases, including subscription and lifetime options	Not stated
Loaflo	AI photo feedback on loaves or starter, recipes, starter tracking, calculators, a chat baking assistant	Free with subscription in-app purchases	States no account needed
Sordo	Step-by-step recipes, starter guide, baking timers, an AI assistant you can ask questions	Free with subscription in-app purchases	Not stated
Sourdough Tracker: Crust	One-tap feeding, countdown to next feed, push reminders, multiple starters, pause mode, iPhone and Apple Watch	Describes itself as free	States no account
Boulie (ours)	Photo rise check, peak prediction, counter/fridge-aware reminders, 100+ recipes, guided bake mode with alarms, hydration calculator, photo journal, rise trends	Subscription (Boulie Pro) with a free trial	No account

Who each one might suit

• Sourdough Starter Tracker looks like a good fit if you want a straightforward tracker with calculators and prefer paying once rather than subscribing.
• Sourflow leans toward the bake itself: detailed timers, temperature logs and fermentation estimates, plus a levain tracker with peak predictions. It suits bakers who want data from every bake session.
• Loaflo is built around AI feedback and a chat assistant, alongside recipes and tracking. It suits you if you want to ask questions and get feedback on your loaves.
• Sordo focuses on recipes, timers and an AI assistant. It suits beginners who want guidance through a bake.
• Crust is the minimalist option: quick feeding logs and reminders, with Apple Watch support. It suits you if your starter is already healthy and you just need a nudge.

How Boulie helps (and where it doesn’t)

We built Boulie around the question “is my starter ready?”.

What Boulie does well:

• Rise check from a photo. Take a photo of the jar and Boulie’s AI reads it to help confirm whether your starter has peaked.
• A prediction engine that learns your starter. Each feed you log includes ratio, flour and kitchen temperature, and Boulie uses that history to show something like “Peaks in ~4 h” on the home screen.
• Counter and fridge modes. Reminders follow where your starter lives: daily on the counter, weekly in the fridge, timed to when it needs feeding.
• The whole bake. 100+ step-by-step recipes, from country loaves to focaccia, bagels, pizza and discard pancakes, with a guided bake mode whose alarms ring through silent mode on iOS 26, plus a hydration calculator.
• A photo bake journal and rise trends so you can see your starter getting stronger over time.
• No account. Your starter log and journal live on your phone. When you use a rise check, the jar photo is sent securely to Boulie’s analysis service to get the reading, and isn’t used for anything else.

Where another app might suit you better:

• You don’t want a subscription. Boulie has a hard paywall: after the free trial, you need Boulie Pro. If you want something free or a one-time purchase, the listings above include both.
• You want a chat assistant to ask open-ended baking questions. Boulie doesn’t have one; Loaflo and Sordo list one.
• You want detailed per-session fermentation logs and Live Activities. Sourflow’s listing focuses on exactly that.
• You’re not on iPhone. Boulie is iOS only today.
• You need your photos to stay on the device at all times. The rise check needs to send the jar photo for analysis. You can still log feeds and use the rest of the app without taking rise-check photos.

How to choose in five minutes

1. Name your real problem. Forgetting feeds? Not knowing when it’s ready? Messy bake days?
2. Check the pricing model in the current App Store listing.
3. Check where it runs: iPhone only, or also Android, Watch, iPad or Mac.
4. Log a week of feeds in your top choice, using the free version or trial.
5. Keep the one you opened without thinking about it. That’s the one that will actually help your starter.

Key takeaways

• The features that matter most are fast logging, counter/fridge-aware reminders and help knowing when your starter is ready.
• Apps range from simple trackers to bake companions to AI-assisted tools. Pick the kind that matches your problem.
• Pricing models differ widely, so check the current listing before committing.
• Boulie is strongest if you want to know when your starter will peak and bake with guidance, and not the right pick if you want a free app or a chat assistant.