Sourdough Ingredient: Egg White (Eiweiß) — Uses, Effects, and Tips

Primary functional effects: coagulation during baking (heat-set protein network), water-binding capacity, and slight emulsification through naturally occurring globulins. These effects can increase crumb stability and help trap gas during early oven spring. Egg white does not provide gluten; it complements gluten by adding a heat-set scaffold, which is why it is more effective in doughs that already have sufficient gluten development [1][2].

Use egg white as a liquid ingredient measured by weight. Weigh all ingredients on a kitchen scale. Typical usage rates: 1–2% of flour weight for subtle effects (e.g., 5 g egg white per 500 g flour), up to 5% in enriched or specialty recipes. For convenience and consistency consider using separated egg white from a jar or fresh separated whites; store separated whites in a glass jar for starter or other sealed container. If separating eggs by hand, use a jar spatula for clean transfer.

Egg whites are ~87% water. When you add egg white, treat it as part of your dough water. Subtract the weight of the egg white from your water addition to maintain target dough hydration. Example: if a formula calls for 360 g water and you add 30 g egg white, reduce added water to 330 g. For precise work always measure with a digital kitchen scale and record adjustments for future repeats [1].

Add egg white with the mixing water at the beginning of bulk mix so it is evenly distributed. Because egg white increases stickiness slightly and changes rheology, watch gluten development: you may need one or two additional sets of folds to reach the same windowpane strength. Use a dough whisk for initial mixing of wet ingredients and a dough scraper to manage the tacky dough during folds. Avoid over-oxidation: long intensive mechanical mixing can denature egg proteins early and reduce their thermal benefit in the oven [1][2].

Egg white is nearly neutral in flavor compared to whole egg yolk. At low inclusion rates it won’t add noticeable egginess but will subtly increase crumb sheen and perceived tenderness due to the coagulated protein network. In enriched doughs (with butter, milk, or sugar) egg white can improve sliceability and reduce crumbliness. For an open crumb in a lean sourdough, keep usage low to avoid tightening the crumb too much [1].

Use fresh egg whites promptly or store them refrigerated at ≤4°C in a sealed container for up to 48 hours; freeze for longer storage. Always practice standard food-safety: refrigerate separated whites, and when using raw egg white in no-bake preparations be aware of salmonella risk. In baked bread, heat coagulation during baking eliminates that risk. Label and date any stored egg white in a clear straight-sided container so you can track freshness [2].

For practical experiments with ingredients and their effects on dough structure consult detailed technique discussions at The Perfect Loaf and Plötzblog, which include tests on protein, hydration, and handling that are directly applicable when you add non-flour proteins like egg white [1][2].