Replacing 180g High-Hydration (125%) Sourdough Starter with Instant or Active Dry Yeast
Liquid-heavy starter reverse conversion: adding back +100g water and +80g flour when swapping 180g (125%) starter for yeast.
Why bother converting back at all? Three reasons. You need a predictable two-hour rise for a schedule; you want the cleaner flavour of a commercial-yeast crumb; or you have 180g of starter in the jar you would rather not waste. The cost is that you lose the acid complexity, so season the dough with the formula's own aromatics.
- Add Back Flour
- +80gReplaces flour inside 180g (125%) starter
- Add Back Water
- +100gReplaces water inside 180g (125%) starter
- Instant Yeast (2-Hr Rise)
- 7.4g (2.4 tsp)For 530g total flour batch
- Preserved Hydration
- 78.3%415g W / 530g F
Gram Weights for Replacing 180g of 125% Hydration Starter
The three yeast formats differ in potency per gram, which is why the Instant column is the baseline the other two are scaled from.
| Target Rise Schedule | IDY Dose | ADY Dose | Fresh Cake Dose | Restoration Required |
|---|---|---|---|---|
| 180g @ 125% (Standard Same-Day (1.5–2 hrs)) [Baseline] | 7.4g (2.4 tsp) | 9.3g (3 tsp) | 22.3g | +80g F & +100g W |
| 190g @ 125% (Slow Artisan Bulk (3.5–4.5 hrs)) Smaller Batch | 3.7g (1.2 tsp) | 4.7g (1.5 tsp) | 11.2g | +84.4g F & +105.6g W |
| 170g @ 125% (Overnight No-Knead / Cold Proof (12–18 hrs)) Larger Batch | 1.3g (0.4 tsp) | 1.6g (0.5 tsp) | 3.9g | +75.6g F & +94.4g W |
| 200g @ 125% (Standard Same-Day (1.5–2 hrs)) Half Size | 7.5g (2.4 tsp) | 9.4g (3 tsp) | 22.6g | +88.9g F & +111.1g W |
| 160g @ 125% (Slow Artisan Bulk (3.5–4.5 hrs)) Double Size | 3.6g (1.2 tsp) | 4.6g (1.5 tsp) | 10.9g | +71.1g F & +88.9g W |
On-Bench Hydration & Fermentation Adjuster
Modify base flour mass, levain inoculation, or ambient kitchen temperature below to recalculate from this +80g baseline.
Why 180g of 125% High-Hydration Starter Requires Asymmetric Water Restoration
Salt interacts with the change. A levain dough was usually formulated for a 2% salt dough, and swapping in 7.4g of commercial yeast on the same 530g of flour keeps that salt level, which is a sensible place to leave the formula alone.
Punching down, shaping and retarding are the stages that a levain dough was really buying you. Removing the starter removes that work, so plan the 1.5 – 2.0 hours warm bulk rise as a single continuous bulk and shape only once, at the end.
Step-by-Step Reverse Conversion Protocol (180g @ 125%)
- Use a Scale, Not a Spoon: 7.4g of instant yeast is 2.4 teaspoons, and a kitchen teaspoon of yeast varies by up to 20% between brands, so weighing is the only accurate approach.
- Combine Everything at Once: 530g flour, 415g water at 100°F (38°C), 7.4g yeast and 2% salt.
- Knead to Windowpane: A commercial-yeast dough develops gluten faster, so stop as soon as the gluten film is smooth and you will avoid tearing it.
- Proof and Bake: Allow 1.5 – 2.0 hours warm bulk rise, shape once, and bake the moment the volume has roughly doubled.
Common Scaling & Troubleshooting Questions (+80g)
What happens to the dough's hydration when I swap out 180g of starter?
Nothing, provided you restore the 80g of grain and 100g of water inside it. The dough stays at 78.3% true hydration on 530g of total grain.
How much flour and water are inside 180g of 125% hydration levain?
180g of 125% hydration sourdough levain contains 80g flour and 100g water.
Can I use Active Dry Yeast instead of Instant Yeast to replace 180g starter?
Yes — multiply the 7.4g Instant Yeast weight by 1.25x and dissolve it in warm (100°F / 38°C) water from your 100g water addition.