How Much Salt in Sourdough? Salt Percentage Calculator
Salt in bread is written as a percentage of the flour weight, like every other ingredient in baker's percentages. This calculator converts that percentage into grams, or grams back into a percentage. It does not tell you what percentage to use: that is a matter of taste and of your recipe.
The math
salt (g) = flour (g) × salt % ÷ 100, and back: salt % = salt (g) ÷ flour (g) × 100.
The only choice is which flour to count. A starter is flour and water, so a recipe can count the flour you add, or the total flour including what is inside the starter. At a starter of 100 g at 100% hydration, the starter holds 50 g of flour (see the hydration calculator). Check which one your recipe means; the two differ.
Worked example
500 g of flour added and 100 g of a 100% starter. These numbers are examples:
| Salt % | Counted on 500 g (flour added) | Counted on 550 g (total flour) |
|---|---|---|
| 1.5% | 7.5 g | 8.25 g |
| 2% | 10 g | 11 g |
| 2.5% | 12.5 g | 13.75 g |
Going the other way, 10 g of salt in that dough is 10 ÷ 500 = 2% of the flour added, and 10 ÷ 550 = 1.82% of the total flour.
Why not just add more salt?
The study behind the temperature guide reports that the sourdough bacterium Lactobacillus sanfranciscensis was completely inhibited at 4% NaCl (Gänzle, Ehmann and Hammes, 1998). That percentage describes the conditions of the experiments, not a bread dough, so do not read it as a baker's percentage of flour. What it shows is that salt slows the bacteria that give sourdough its acid, so a lot of salt works against the starter.
Sources
- Baker's percentage arithmetic: the definition of each ingredient as a percent of flour weight. All numbers above are computed with it.
- Gänzle, M. G., Ehmann, M., and Hammes, W. P. (1998). Modeling of Growth of Lactobacillus sanfranciscensis and Candida milleri in Response to Process Parameters of Sourdough Fermentation. Applied and Environmental Microbiology 64(7):2616–2623.