Sourdough starter from scratch in 7 days

Day 1 1/8 cup (30g) filtered water 1/3 cup (30g) whole wheat or rye flour (lightly spooned in - do not pack) Mix water and flour of your choice together in a Mason jar (or glass canister). Loosely cover (you’ll want room for airflow). Let sit at 80F (27C) for 24 hours (near a window in a sunny room, or inside a turned-off oven). Day 2 1/8 cup (30g) filtered water 1/3 cup (30g) whole wheat or rye flour (lightly spooned in - do not pack) You’ll see activity in your jar today (bubbles, volume, bad smell). Add more water and flour to your existing mixture and stir well. Loosely close the lid and store at 80F (27C) for 24 hours. Day 3 2 tbsp + 2 1/4 tsp (20g) whole wheat or rye flour (generous scoops) 4 tsp (20g) filtered water 3 tsp (20g) ripe starter You’ll see activity in your jar today (bubbles, doubled volume, bad smell). Separate 3 tsp (20g) of starter into a new jar. Add water and flour to the new jar and stir well (1:1:1 by weight). Loosely close the lid and store at 80F (27C) for 24 hours. Day 4 2 tbsp + 2 1/4 tsp (20g) whole wheat or rye flour (generous scoops) 4 tsp (20g) filtered water 3 tsp (20g) ripe starter You’ll see activity in your jar today (bubbles, doubled volume, bad smell). Separate 3 tsp (20g) of starter into a new jar. Add water and flour to the new jar and stir well (1:1:1 by weight). Loosely close the lid and store at 80F (27C) for 24 hours. Day 5 2 tbsp + 2 1/4 tsp (20g) whole wheat or rye flour (generous scoops) 4 tsp (20g) filtered water 3 tsp (20g) ripe starter Your starter is almost ready (smells better, doubled in volume). You’ll need to feed it 2 times a day now, morning and evening. Each feeding should follow the same procedure as days 3 and 4 (single feeding measurements above - 1:1:1 ratio by weight) Day 6-7 2 tbsp + 2 1/4 tsp (20g) whole wheat or rye flour (generous scoops) 4 tsp (20g) filtered water 3 tsp (20g) ripe starter Your starter is ready, but we want it to have even more strength. Keep feeding it 2 times a day like you did on day 5 (single feeding measurements above - 1:1:1 ratio by weight) Day 8 (if needed) 2 tbsp + 1 1/8 tsp (10g) whole wheat or rye flour (generous scoops) 2 tsp (10g) filtered water 3/4 tsp (5g) ripe starter Your sourdough starter should be ready for baking, but let’s make sure. To test for readiness, drop a tablespoon of starter into a bowl of room temperature water If it floats, it’s ready to use. If it doesn’t, allow more time to ferment. If needed, continue to feed it 2 times a day (single feeding measurements above - ratio 2:2:1 by weight). Day 9 and Beyond (if needed) 5 tsp (15g) whole wheat or rye flour 2 1/2 tsp (15g) filtered water 3/4 tsp (5g) ripe starter Continue checking the progress of your starter using the float test (used on day 8). If needed, continue feeding 2 times a day and increase the feeding ratio (single feeding measurements above - ratio1:3:3 by weight). If your starter reaches peak volume in less than 12 hours and starts to deflate, it means it matures and gets hungry faster than you are feeding it. It’s time to increase the feeding ratio to 1:4:4 Troubleshooting Your Sourdough Starter Issue: No Activity Try one more time. Start a fresh batch and follow the feeding instructions for 1 week. If you do not see any activity this time, something is wrong with your flour. Start again using a new brand of flour. Issue: Water on the Surface This liquid is a naturally occurring alcohol which indicates that it’s a little past time to feed your starter, and is an indication of a weak starter. Pour it off or stir it into your starter, then feed it. Issue: Mold Not good, your flour is stale, expired, or has mold spores in it. You will need to replace it with new flour. Issue: Rising too Much This is a very good sign. Just use a bigger jar. Next time, use less flour and water to keep your starter from overflowing your jar.