Understanding Hydration: A Sourdough Test Bake

Build the levain: Mix starter, flour, and water. Ferment at 24–26°C (75–79°F) until domed, bubbly, and at least doubled (typically 3–4 hours).

Set up the experiment: Label three bowls or containers as 65%, 75%, and 85%. Weigh 300 g flour into each. Weigh water into separate cups: 195 g (65%), 225 g (75%), 255 g (85%).

Autolyse (optional but recommended for consistency): Add the water for each dough to its flour and mix until no dry flour remains. Cover and rest 30 minutes at room temperature.

Add levain: Add 60 g levain to each bowl. Mix until mostly integrated (pinch-and-fold or slap-and-fold). Rest 10 minutes.

Add salt: Sprinkle 6 g salt onto each dough. Mix until fully dissolved and the dough begins to smooth. For the 85% dough, use wet hands and mix gently to avoid tearing; for the 65% dough, expect a tighter feel.

Bulk fermentation (keep all doughs at the same temperature): Ferment 3–5 hours at 24–26°C (75–79°F), performing 3 sets of folds in the first 90 minutes. Do one set every 30 minutes: for 65% use stretch-and-fold; for 75% use stretch-and-fold or coil folds; for 85% use coil folds to preserve structure.

Track fermentation: After the last fold, let the doughs rise undisturbed until they show a 40–70% volume increase and feel aerated. Expect the higher-hydration dough to ferment and relax faster. Record time to reach the same rise for each dough.

Pre-shape: Turn each dough onto a lightly floured surface. Gently pre-shape into a round. Rest 15–20 minutes uncovered.

Final shape: Shape each dough into a tight boule or small batard. Use as little flour as needed; the 85% dough may require a bench scraper and lightly wet hands. Place seam-side up in well-dusted bannetons or towel-lined bowls.

Cold proof: Cover and refrigerate all three doughs 12–16 hours at 4°C (39°F). This equalizes scheduling and makes scoring easier, especially for higher hydration.

Preheat: Place a Dutch oven (or baking stone with a covered steam setup) in the oven and preheat to 250°C (485°F) for at least 45 minutes.

Bake (one at a time): Remove one dough from the fridge, invert onto parchment, score. Bake covered 20 minutes at 250°C (485°F), then uncover and bake 15–20 minutes at 230°C (450°F) until deeply browned and the loaf feels light. Repeat for remaining doughs, reheating the Dutch oven between bakes.

Cool and evaluate: Cool at least 2 hours before slicing. Compare handling notes, spread vs. height, crust thickness, and crumb: 65% tends toward tighter, more uniform crumb; 75% balances openness and strength; 85% can be very open but is more prone to spreading if gluten development or fermentation is off.