Lesson #1: Your Starter’s Birthday: Days 1 and 2
The first two days of building a sourdough starter from scratch, flour, water, a jar, and a little faith.
Everything you need for Day 1: high protein flour, a jar, and a little faith.
If you just signed up for the starter course, welcome. You’re two ingredients and ten minutes away from officially starting something. This page covers exactly what to do today and tomorrow. Instructions for the rest of the days will land in your inbox starting Day 3, so keep an eye out.
Desi’s Note
This first stretch is the least exciting part and also the part people quit during, because nothing dramatic happens yet. Nothing is supposed to happen yet. You’re not behind.
🧺 What You Need
100 g (¾ cup + 1 Tbsp + 1 tsp) high protein flour (12 to 14 percent protein)
I use Caputo Chef 00, but any high protein flour works fine here.
Day 1
💧 100 g (¾ cup + 1 Tbsp + 1 tsp) filtered water, lukewarm
Day 1
🌾 50 g (6 Tbsp + 2 tsp) same high protein flour (12 to 14 percent protein)
Day 2
💧 50 g (3 Tbsp + 1 tsp) filtered water, lukewarm
Day 2
A clean jar, a rubber band, and something loose to cover it with
(the lid set on top, not sealed, a plastic bag, or plastic wrap)
Setup
Day 1
🥣 Mix It
Mix 100 g lukewarm filtered water with 100 g flour, right in the jar you plan to keep it in. Mix well until you get a thick, shaggy consistency, closer to pancake batter than dough. Cover the jar loosely and wrap a rubber band around the outside at the current level, so you can actually see if anything moves.
Leave it on the counter for a full 24 hours. Don’t stir it, don’t check on it every hour, don’t panic if it looks exactly the same the whole time. Day 1 is just giving the wild yeast and bacteria already living in the flour a chance to wake up. Unless your kitchen runs especially hot and humid, expect to see little to no movement yet, and that’s completely normal.
Day 2
🔄 Discard and Feed
Discard all but 50 g of what you mixed yesterday. That discard isn’t usable in discard recipes yet since the starter hasn’t activated, so it’s fine to just toss it. To the 50 g that’s left, add 50 g water and 50 g flour. Mix well, cover loosely again, and reset your rubber band at the new level so you have a fresh line to measure against tomorrow. Leave it on the counter at room temperature for another 24 hours.
What’s Next
Days 3 and beyond are where things actually start moving, bubbles, smell changes, the whole show. Keep an eye out for our next email, it’ll walk you through the rest of the process of creating your own starter.
More Resources
Looking for a printable reference? Browse all six Printable Quicksheets, or dial in your own numbers with the Sourdough Calculator.
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