Sourdough sandwich bread can have a soft, fairly even crumb when its formula, mixing, fermentation, and shaping suit a pan loaf. This version uses natural starter, butter, and sugar. Including the levain, it has 525g flour and 325g water: about 61.9% hydration, or 62.8% estimated water when butter moisture is counted. Readiness and freshness cannot be guaranteed by a float test, a 24-hour schedule, or the word sourdough.
Sourdough does not have to be a crusty boule. A pan supports the dough, and butter, sugar, and deliberate shaping can help produce a loaf suited to sandwiches and toast. A healthy levain provides the leavening here, with no added commercial yeast.
The ingredient weights below are retained from the original recipe, with corrected percentages and a coherent sequence. The exact 909g formula, its fit and proof height in a particular 9x5-inch pan, and its fermentation and baking times still need a documented kitchen trial together. Use the dough cues rather than expecting a guaranteed mild flavor or five-day softness.
Our yeasted sandwich bread uses a related pan-loaf approach. A separately developed example from King Arthur uses both levain and instant yeast; its much shorter final-dough rises should not be transferred to this naturally leavened formula.
What Makes a Sandwich Loaf Soft?
A fairly firm dough can be easier to shape into an even crumb, but hydration does not determine hole size by itself. Mixing, flour, fermentation, shaping, and baking all contribute. Sandwich loaves and artisan breads each cover a wide range of hydrations; neither requires a universal 65–68% or 72–80% range.
Butter and sugar can tenderize bread, but they do not stop staling or establish a fixed shelf life. Firming involves starch reorganization and water redistribution as well as formula and storage conditions. A soft crumb on the first day is not evidence that it will remain equally soft for five or six days.
A regularly refreshed, vigorous starter and levain used before prolonged collapse can help you pursue a milder loaf. However, 100%-hydration starter is not automatically mild, and warmer fermentation does not reliably reduce sourness. Culture, flour, feeding, temperature, maturity, and the final dough’s fermentation all matter. King Arthur’s own sourness trials produced a more sour loaf with a warmer, wetter levain in that particular process. That is a useful counterexample to a universal “warm and liquid means mild” rule.
Formula and Levain Accounting
Yield: one loaf from approximately 909g dough before handling and baking losses. The intended pan is an open 9x5-inch loaf pan, not a lidded Pullman pan.
Levain build
| Ingredient | Weight |
|---|---|
| Healthy, ripe starter at 100% hydration | 15g |
| Bread flour | 75g |
| Water | 75g |
This builds 165g at 100% hydration. Use 150g in the dough, leaving roughly 15g before handling losses. The hydration of the seed starter matters: it contributes flour and water too. Weigh it rather than treating a tablespoon of aerated starter as an exact 15g measure.
Mix in a clean container with room for expansion and cover. Around 75–78°F (24–26°C), 8–12 hours is an initial planning estimate. Watch for clear expansion and an aerated structure, using your starter’s repeatable feeding behavior to judge readiness. If it is already ripe earlier, use it rather than waiting for the overnight clock.
The float test detects buoyancy, not peak leavening strength or acidity. In King Arthur’s first-party test, starter floated before it was considered ripe. Do not make floating the required signal to proceed or use it to establish a “young, mild peak.”
Final dough additions
| Ingredient added at final mixing | Weight | Percentage of 525g total flour |
|---|---|---|
| Bread flour | 450g | 85.71% |
| Water | 250g | 47.62% |
| Levain, containing 75g flour and 75g water | 150g | 28.57% as a combined ingredient |
| Unsalted butter, softened | 30g | 5.71% |
| Sugar | 20g | 3.81% |
| Salt | 9g | 1.71% |
The flour within the levain completes the total flour to 100%. Do not count the 150g levain again after counting its component flour and water. The prefermented flour is 75 ÷ 525 = 14.29%.
Total flour is 450 + 75 = 525g. Total plain water is 250 + 75 = 325g, giving 325 ÷ 525 × 100 = 61.90% hydration. If butter is estimated at 16% water, its 30g adds about 4.8g water: 329.8 ÷ 525 × 100 = 62.82%. It cannot raise this formula to 65–67%. Actual butter composition varies. See baker’s percentages and King Arthur’s approximate ingredient-water fractions for the accounting conventions.
Try It Yourself
The Baker's Bench
Use 525g total flour and 325g plain water, including the 150g levain, when checking this formula. Butter moisture is a separate estimate. Calculator output can help scale weights; it cannot establish this loaf's fermentation or pan fit.
Open ToolEquipment
- Kitchen scale and mixing bowl
- Dough hook mixer, if using one, within its rated capacity
- Open 9x5-inch loaf pan
- Probe thermometer and cooling rack
- Food-safe cover that prevents a dry skin without restraining the rising dough
Method
1. Rest the flour and water
Mix the 450g flour with 250g water until no dry pockets remain. Cover and rest about 20–30 minutes if desired. This flour-and-water autolyse is quite stiff because the levain water has not yet been added.
Resting can improve handling, but it is optional. It does not guarantee complete hydration in a set number of minutes or a superior crumb in every formula. King Arthur’s autolyse comparisons show recipe-dependent effects; an unsupported consensus among “all five major bread authors” is unnecessary.
2. Incorporate the remaining ingredients
Add the 150g levain, softened butter, sugar, and salt. Mix until all are evenly incorporated, then knead until the dough is smooth, cohesive, and elastic. A gently stretched piece should show some extensibility without immediate tearing, but do not chase a paper-thin windowpane at the expense of an overheating dough or mixer.
Mixer: Follow its dough instructions, including maximum batch size and kneading duration. KitchenAid specifies Speed 2 for yeast dough; the original instruction to increase to medium speed for 5–7 minutes was not appropriate as universal guidance.
By hand: Squeeze and fold until the levain and enrichments are distributed, then knead and rest as needed. The original 6–8 minutes is an estimate, not a required development endpoint.
A mixed dough temperature around 76–78°F (24–26°C) is a working target for this schedule, not a magic optimum. Choose water temperature from the measured ingredient and room temperatures; fixed 85°F water cannot ensure it. A desired-dough-temperature calculation for dough with a preferment includes the levain temperature as an additional factor. Butter and the preceding rest make checking the actual dough especially useful.
3. Bulk ferment, with early folds if needed
Put the dough in a lightly greased, covered container and mark its starting level. At about 30 and 60 minutes, give a gentle set of folds if it needs strength; a third around 90 minutes is optional. Do not tear a dough that is already tight. These folds occur within bulk fermentation.
The original 8–12-hour bulk range is an estimate requiring verification with this formula and starter. Check development earlier. Aim for substantial expansion toward doubling, visible aeration, and enough strength to shape. If the dough reaches that condition sooner, proceed. If it remains dense, assess temperature and starter strength; if it becomes slack, shredding, or collapses, more time is unlikely to repair it.
A morning mix followed by an 8–12-hour bulk ends that afternoon or evening, not the following morning. Do not add another overnight hold solely to match a diagram. Choose a start time that lets you monitor the dough and complete the final proof and bake.
Later handling should be gentle, but there is no universal ban on folds in the last hour across all bread methods. Here the planned folds are early so the dough can expand afterward. Use a measured, moderate proofing location; an oven light is not a thermostat, and some enclosed spaces become too warm.
Sourdough Sandwich Bread: Sequence and Readiness
Elapsed times are estimates, not a fixed 24-hour or three-day schedule
Build levain
15g starter + 75g flour + 75g water. At 100% seed hydration, this makes 165g; use 150g.
Assess levain
Look for substantial expansion and aeration. An 8–12-hour estimate and a float test cannot certify readiness or acidity.
Flour-water rest
Combine the final-dough flour and water, then rest covered before adding the other ingredients.
Mix
Incorporate levain, butter, sugar, and salt. Use the mixer's permitted dough speed and check the actual dough temperature.
Fold and ferment
Early folds are included in bulk. The 8–12-hour range needs verification; inspect sooner and proceed when expanded, aerated, and still strong.
Shape and pan
Gently remove large bubbles, shape a log, and place in the open 9x5-inch pan.
Final rise
The 2–4-hour range is an estimate, not an overproofing allowance. Assess puffiness, pan height, and dough feel together.
Bake
Use 375°F as the starting setting and check from 35–40 minutes. Bake through, release safely, and cool completely before slicing.
Illustrative stages. Watch the dough's readiness cues as well as the clock.
Equal-size drawings are illustrations, not volume measurements. The levain build, bulk rise, and final proof are separate stages; sourdough does not guarantee a wider proofing margin than commercial yeast.
jayarrbread.com4. Shape for the open pan
Turn out the dough and gently press out conspicuously large bubbles. Pat it into a rectangle with a short edge slightly shorter than the pan. Fold and roll into an even log, sealing the seam without tearing; place seam-side down in the greased pan.
The original half-full or two-thirds-full starting rules were too broad. Pan depth, taper, dough weight, and prior expansion all affect apparent fill. Record how this 909g batch fits your particular pan rather than using those fractions as a universal loading test.
5. Final proof
Cover and let the dough become puffy and well expanded. For the stated open pan, a crown around 1 inch above the rim is a starting cue, used alongside the dough’s condition. Do not continue until an exact height if the loaf is already fragile or collapsing. This above-rim instruction does not apply to a pan baked with a lid.
The original 2–4 hours describes an estimated duration, not a two-hour interval in which proof is equally good. A gentle indentation that slowly recovers partway can provide supporting information, but surface dryness, temperature, and dough strength affect it. No response is not a unique diagnosis. Proofing guidance emphasizes dough cues and temperature rather than treating time ranges as guarantees.
Preheat to 375°F (191°C) as the loaf approaches readiness, allowing your oven to reach its actual baking temperature.
Try It Yourself
The Starter Clock
Use Starter Clock as an observation and planning aid. It cannot measure your levain's acidity, prove a mild-flavor peak, or replace checking actual expansion and dough condition.
Open Tool6. Bake and cool fully
Bake at 375°F (191°C) and begin checking around 35–40 minutes. This is a starting range for the retained formula, not a validated bake time. Look for a browned top and set sides. A center reading around 190–195°F (88–91°C) can support the assessment, but cannot establish correct fermentation or guarantee a non-gummy crumb. If it still seems underbaked, continue; tent the top if it is browning too quickly.
There is no single 380°F rule for enriched breads. Pan material, loaf size, and formulation influence the setting and duration. A hollow sound is less dependable than considering the bake as a whole.
Release the loaf from the pan as soon as practical without tearing it or risking a burn, then cool on a rack. Wait until fully cool before slicing or enclosing in a bag. One hour is not a guaranteed cooling time for every loaf or kitchen. Use a serrated knife with a light sawing motion.
Storage and Freshness
Keep the cooled, unfilled loaf well wrapped for the portion you plan to eat soon. Slice and freeze the rest promptly for longer storage; wrapping and freezer conditions determine quality. The original five- or six-day softness promise, “two days longer than yeasted bread,” and guaranteed two- to three-month quality were not established for this recipe.
Selected sourdough organisms can delay particular spoilage molds in controlled studies. For example, a study of strain FST 1.7 tested defined bread and spoilage organisms. That does not prove your household loaf is mold-resistant for a set number of days. Discard the whole loaf if mold appears; USDA treats bread as a porous food.
Refrigeration often firms bread faster, but “never refrigerate” is too broad. Hot, humid conditions may make refrigeration a practical tradeoff, and sandwiches with perishable fillings need their own food-safety handling. King Arthur’s storage observations discuss that climate exception. Keep perishable foods appropriately refrigerated at 40°F or below. See our bread storage guide for more.
Variations Need Their Own Adjustments
Whole wheat: Replacing some white flour can change water demand and dough strength. A 20–30% substitution is a possible experiment, not a universal validated variation with exactly 15–20g extra water. Count the flour in the levain when stating the whole-grain percentage and record the result. The whole wheat bread guide discusses the broader handling differences.
Honey and oats: Honey is not dry sugar: it brings water and a different sugar mixture. Oats also alter water demand and dough structure. The original 30g honey plus 40g oats addition is not a tested equivalent of the base loaf. Use a developed honey-oat sourdough recipe for a reliable starting point.
Milk: Replacing 125g water with 125g whole milk adds milk solids and supplies only about 109g water using an 87% estimate. It therefore lowers estimated water by about 16g; it is not hydration-neutral. A milk version needs its own handling and timing checks, not a fixed 85°F milk instruction.
Troubleshooting
Too sour: Look at levain maturity and the entire fermentation, rather than assuming one float result or warm temperature will control flavor. Use a reliably refreshed starter and record when the levain reaches its normal ripe state. Avoid deliberately extending an already-ready fermentation.
Poor rise: Check starter performance after feeding, actual dough temperature, ingredient weights, and dough development. More time may help an underfermented dough; it will not repair an overfermented, weakened one. Adding 2–3g instant yeast to an arbitrary discard is not a validated two- to four-hour conversion of this recipe.
Dense or gummy crumb: Consider underfermentation, overfermentation and weakening, inadequate mixing, bake duration, flour changes, and slicing while warm. A center temperature alone cannot rule these causes out.
Large irregular holes: Large trapped shaping pockets can contribute, but uneven fermentation and development can also matter. Press out obvious large bubbles gently and shape evenly; do not crush out all the gas.
See our bread troubleshooting guide and beginner sourdough guide for related checks.
Frequently Asked Questions
- How do I make sourdough sandwich bread less sour?
- Start with a healthy, regularly refreshed starter, use the levain while active before prolonged collapse, and avoid extending fermentation once the dough is ready. Track the whole process. Liquid starter and warmer fermentation do not universally produce milder bread, and a float test cannot measure acidity.
- What is this recipe's hydration?
- The 150g levain supplies 75g flour and 75g water. Total flour is 525g and plain water is 325g, giving 61.9% hydration. Estimating the butter at 16% water raises that to about 62.8%, not 65–67%. Total mixed dough is about 909g.
- Can I use sourdough discard for sandwich bread?
- Discard describes a portion removed during feeding, not a fixed level of activity. This naturally leavened recipe requires a vigorous levain. An unfed starter may still be active, but an arbitrary discard-and-instant-yeast substitution needs a separate formula and schedule.
- Why is my sourdough sandwich bread dense?
- Possible causes include weak starter performance, insufficient or excessive fermentation, inadequate dough development, pan loading, and the bake. Check observations from mixing onward. Floating does not prove levain readiness, and simply waiting longer is not always the remedy.
- Does sourdough give me a two-hour proofing margin?
- No. An estimated 2–4-hour proof is a possible duration range under different conditions, not two hours of equal readiness. Watch the actual loaf; temperature, starter activity, dough strength, and pan size affect when it should bake.
- How long does sourdough sandwich bread stay fresh?
- This formula has no verified five- or six-day freshness period. Wrap the fully cooled loaf, keep only what you will use soon, and freeze the rest. Mold inhibition shown for selected cultures does not certify a household loaf. Discard moldy bread entirely; refrigeration may be appropriate in hot, humid conditions or for perishable fillings.
- Can I use whole wheat flour?
- You can experiment with a partial substitution, but this formula's whole-wheat version has not been tested. Water needs and handling vary. Count levain flour in the total and do not assume that exactly 15–20g extra water or a faster fermentation will work in every case.
