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The Sourdough Glossary

This glossary is a precise, science-checked reference to the language of sourdough — every term a home or professional baker meets across the whole lifecycle, from feeding a starter to reading the crumb. Each entry gives a one-line definition, the mechanism or reason it matters, and links to related terms, so you can use it as a quick lookup or read it straight through to understand why the craft works the way it does. Definitions favor the actual chemistry, biology, and physics over kitchen folklore, with common misconceptions quietly corrected along the way.

127 terms · 12 categories · science-checked

Starter & Levain

Sourdough Starter culture, mother culture

A stable, self-perpetuating colony of wild yeast and lactic acid bacteria living in a flour-and-water medium, maintained by regular feeding.

It is the loaf’s sole leavening and souring agent — the yeast generate CO2 for rise while the bacteria generate organic acids for flavor and preservation. A healthy culture is a stable symbiosis, so its behavior (rise time, aroma, acidity) is reproducible once feeding and temperature are controlled.

Related Levain·LAB·Wild Yeast·Backslopping

Levain leaven, sponge, build

An off-shoot of the starter built specifically for a single bake, mixed to a chosen flour, hydration, and ratio so it peaks when the dough is ready.

Building a dedicated levain lets the baker tune flavor and timing independently of the mother — a stiffer, cooler, or smaller-inoculation levain shifts the acid balance and the speed of fermentation for that one dough.

Mother chef, mother dough

The maintained “parent” culture kept alive between bakes, from which levains are drawn.

Keeping a single long-lived mother preserves the established microbial community, which is what gives a bakery its consistent house character over months and years.

Hooch

The thin, grey-to-amber liquid layer of fermentation byproducts (ethanol and water) that collects on an underfed starter.

It signals the culture has exhausted its food and is hungry, not that it is dead or spoiled; it is a weak solution of water, ethanol, and a little acid from yeast/LAB metabolism, and can be stirred in or poured off before feeding.

Discard

The portion of starter removed and set aside before each feeding to keep the population at a manageable size.

Discarding caps the total mass so a fixed feed delivers a high enough fresh-flour ratio to lower acidity and restart vigorous growth; the removed acidic culture is useful in non-rising recipes.

Feeding Ratio refreshment ratio

The proportion of existing starter to fresh flour to water at each refresh, written as starter:flour:water (e.g., 1:5:5).

A larger flour share dilutes accumulated acid and extends the time to peak, favoring milder, yeast-forward cultures; a smaller share peaks faster and accumulates more acid. It is the baker’s main lever over both timing and sourness.

Backslopping

The practice of inoculating a fresh batch by carrying over a small amount of a previous, already-fermented batch.

Serial backslopping is artificial selection: each cycle enriches the organisms best adapted to your flour, hydration, and temperature, which is how a sourdough culture stabilizes into a distinctive, robust community.

Inoculation Percentage seed percentage

The amount of starter or levain added to a build, expressed as a baker’s percentage of the flour being fermented.

Higher inoculation means more cells at the start, so fermentation finishes sooner; lower inoculation lengthens the process, which generally develops more acid and aromatic complexity. It is the cleanest single dial for controlling fermentation time.

Bulk Fermentation Calculator →

Peak maturity, ripe

The point at which a starter or levain has reached maximum volume and gas-holding before it begins to collapse.

At peak, yeast activity and population are near their height while acidity has not yet over-deflated the gluten, so the culture has the most leavening power per gram — the ideal moment to mix it into dough.

Float Test

A quick check in which a spoonful of starter is dropped in water; if it floats it is judged gassy enough to use.

Floating indicates the matrix is saturated with trapped CO2, a rough proxy for activity — but it is unreliable, because a stiff or recently-stirred sample can fail or pass regardless of true readiness. Treat it as a hint, not proof.

Related Peak·Jiggle Test·Wild Yeast

Stiff Levain sweet stiff levain, pasta madre, lievito madre

A levain built at low hydration (roughly 50–60%), producing a dense, dough-like culture.

Frequent refreshment and low water keep total acidity low, giving a sweeter, milder, less sharply sour ferment — the basis of many enriched and Italian breads (lievito madre).

Hydration Calculator →

Liquid Levain poolish-style levain

A levain built at high hydration (around 100% or more), producing a pourable, batter-like culture.

Abundant water and a warmer, looser environment favor lactic-acid production, yielding a milder, yogurt-like tang and faster activity than a stiff build.

Hydration Calculator →

Lactic Acid Bacteria LAB

The group of bacteria (chiefly Lactiplantibacillus, Fructilactobacillus, formerly “Lactobacillus”) that dominate a sourdough culture and produce its organic acids.

LAB produce lactic and acetic acids plus aroma compounds; they vastly outnumber the yeast (often ~100:1) yet contribute little gas, so they drive flavor, dough acidification, and shelf life rather than rise. The canonical sourdough LAB is Fructilactobacillus sanfranciscensis (formerly Lactobacillus sanfranciscensis).

Wild Yeast Saccharomyces, Kazachstania

The naturally occurring yeasts in a sourdough culture — commonly Kazachstania humilis (formerly Candida milleri) and strains of Saccharomyces — that ferment sugars to CO2 and ethanol.

Wild yeast supplies essentially all the leavening gas; alongside Kazachstania humilis, Saccharomyces cerevisiae is the common partner yeast. Many sourdough strains are maltose-negative and acid-tolerant, letting them coexist with LAB by feeding on different sugars rather than competing.

Related LAB·Symbiosis·CO2·Sourdough Starter

Symbiosis yeast–LAB association

The stable, mutually compatible coexistence of wild yeast and lactic acid bacteria within a starter.

The partners partition resources — many sourdough yeasts leave maltose for the bacteria while consuming glucose — and the acidic, somewhat alcoholic environment they jointly create excludes most spoilage organisms, making the culture self-stabilizing.

Sour / Tang sourness

The perceived acidity of the finished bread, set by the type and quantity of organic acids produced during fermentation.

Lactic acid tastes mild and yogurt-like and is favored by warm, wet, fast ferments; acetic acid tastes sharp and vinegary and is favored by cool, stiff, slow, oxygen-available conditions. Bakers steer the ratio by adjusting temperature and hydration, not by “fermenting longer” alone.

Related Lactic Acid·Acetic Acid·pH·TTA

Ingredients & Flour Science

Bread Flour

A high-protein wheat flour (roughly 12–14% protein) milled for strong gluten development.

More gluten-forming protein means a stronger, more extensible-yet-elastic network that traps more gas and tolerates long fermentation, supporting taller loaves and a more open crumb than all-purpose flour.

Whole Grain Flour wholemeal

Flour milled from the entire wheat kernel, retaining bran, germ, and endosperm.

The bran and germ add enzymes, minerals, and wild microbes that accelerate fermentation, but bran fragments also physically cut gluten strands and absorb water, tending to produce a denser crumb and requiring more hydration and gentler handling.

Hydration Calculator →

Rye Flour

Flour milled from rye grain, low in functional gluten and high in pentosan gums and enzymes.

Rye forms little elastic gluten, relying instead on pentosans (arabinoxylans) for structure and very high water absorption; its high amylase activity makes it ferment fast and benefit from the acidity of sourdough, which restrains starch-degrading enzymes that would otherwise cause a gummy crumb.

Spelt Flour

An ancient hexaploid wheat whose flour has gluten that is abundant but more fragile and extensible than modern bread wheat.

Spelt hydrates quickly and reaches gluten development fast, but the network tears easily and is intolerant of over-mixing or over-fermentation, so it wants gentler handling and tighter timing.

Protein Content

The percentage of protein in a flour, the practical predictor of gluten-forming potential.

Higher protein generally yields more gluten and greater water absorption and dough strength — but protein quality (the glutenin/gliadin balance) matters as much as quantity, so two flours at equal protein can behave differently.

Gluten glutenin & gliadin

The viscoelastic protein network formed when the wheat proteins glutenin and gliadin are hydrated and worked together.

Glutenin contributes elasticity and strength (it forms long, cross-linked chains via disulfide bonds) while gliadin contributes extensibility and flow; their balance, plus disulfide and hydrogen bonding, builds the gas-trapping membrane that lets bread rise.

Glutenin

The high-molecular-weight wheat protein responsible for dough elasticity and strength.

Its long subunits link through disulfide bonds into an extensive elastic network; flours rich in quality glutenin resist over-stretching and hold structure through long fermentation.

Gliadin

The wheat protein fraction that gives dough its extensibility and viscous flow.

Gliadins are smaller, largely monomeric proteins that act as a “plasticizer,” letting the elastic glutenin network stretch without tearing — essential for the dough to expand around gas bubbles.

Related Gluten·Glutenin·Extensibility

W Value strength index

A measure of flour strength from the Chopin alveograph, expressing the work needed to inflate a dough bubble until it bursts.

Higher W flours resist deformation and tolerate long fermentation and high hydration; bakers use W (together with the P/L extensibility ratio) to match a flour to a process — high-W for long-retard sourdough, lower-W for quick or tender goods.

Falling Number

A standardized index (in seconds) of a flour’s alpha-amylase activity, measured by how fast a stirrer falls through heated flour paste.

A low falling number means high amylase (often from sprout damage), which over-degrades starch and yields sticky, gummy crumb; a very high number means low enzyme activity and sluggish fermentation. It tells the baker how enzymatically “hot” a flour is.

Ash Content

The mineral residue left after a flour sample is incinerated, expressed as a percentage and used to grade flours (e.g., French Type 55, German Type 550).

Minerals concentrate in the bran, so higher ash signals higher extraction (more bran/germ), more enzymes and microbial nutrients, and faster, more flavorful but weaker-structured doughs.

Extraction Rate

The proportion of the wheat kernel retained in the flour after milling (100% = whole grain; ~72% = typical white flour).

Higher extraction keeps more bran and germ, raising enzyme activity, mineral content, water absorption, and fermentation speed while lowering gluten functionality — the central trade-off between flavor/nutrition and rise.

Diastatic Malt malted flour

Sprouted-then-dried grain (usually barley) milled to a powder that retains active amylase enzymes.

Its amylase breaks damaged starch into fermentable sugars, feeding yeast and boosting browning and oven spring — but a heavy hand causes sticky, gummy crumb, which is why most strong bread flours add only a trace. (Non-diastatic malt is heat-killed and adds sweetness/color only, with no enzyme activity.)

Amylase

The starch-splitting enzyme class (alpha- and beta-amylase) that converts starch into fermentable sugars.

Amylase liberates the maltose and glucose that yeast and LAB ferment; too little starves fermentation and yields pale crust, too much (high amylase / low falling number) over-liquefies starch into a sticky crumb. Sourdough acidity helpfully tempers excess amylase activity.

Protease

The enzyme class that cleaves proteins, including gluten.

Controlled protease activity (and the acidity of long ferments) relaxes gluten and improves extensibility, but excess — common in long, warm, very acidic ferments — degrades the network into a slack, soupy dough that won’t hold shape.

Enzymes flour enzymes

The naturally present biological catalysts in flour (amylases, proteases, lipases, xylanases) that act on starch, protein, fats, and pentosans.

Enzyme activity governs sugar supply for fermentation, gluten softening, crust color, and crumb texture; it rises with extraction, hydration, and warmth, which is why whole-grain and high-extraction doughs ferment faster and degrade sooner.

Starch

The glucose-polymer granules (amylose and amylopectin) that make up the majority of flour by weight.

Starch provides the substrate for amylase (and thus fermentable sugar), absorbs a large share of dough water, and — critically — gelatinizes in the oven to set the crumb’s structure once gluten has done its job.

Damaged Starch

Starch granules mechanically ruptured during milling, making them far more accessible to water and enzymes.

Damaged starch absorbs several times its weight in water (raising effective hydration) and is readily hydrolyzed by amylase into fermentable sugar; modest levels feed fermentation, but excess produces sticky dough and gummy crumb.

Hydration Calculator →

Pentosans arabinoxylans

Non-starch cell-wall polysaccharides, abundant in rye and bran, that bind large amounts of water.

In low-gluten flours like rye they form much of the gas-holding structure and dramatically raise water absorption; they also influence dough stickiness and crumb moistness, which is why rye recipes look and behave so differently from wheat.

Salt role in dough

Sodium chloride, typically added at 1.8–2.2% of flour weight.

Salt tightens and strengthens gluten (shielding charges so glutenin chains pack closer), slows yeast and enzyme activity to control fermentation pace, and is essential for flavor; an unsalted dough ferments too fast and turns slack and sticky.

Baker's Percentage Calculator →

Water and chlorine

The hydrating medium that activates gluten, enzymes, and microbes; its temperature and mineral content affect dough behavior.

Water is the solvent in which every reaction happens, and water temperature is the baker’s main tool for hitting desired dough temperature. Heavy chlorination or chloramine can mildly suppress a young or fragile culture, so some bakers de-chlorinate; an established starter is generally robust to ordinary tap water.

Hydration Calculator →

Dough Conditioners

Added agents (e.g., ascorbic acid, enzymes, emulsifiers like DATEM) that modify dough strength, handling, or shelf life.

Ascorbic acid promotes disulfide bonding to strengthen gluten and improve oven spring; emulsifiers and added enzymes soften crumb and slow staling. Traditional sourdough usually avoids them, relying on fermentation and technique instead.

Related Gluten·Dough Strength·Enzymes

Formula & Ratios

Baker's Percentage baker's math

A formula notation in which every ingredient is expressed as a percentage of total flour weight, with flour always equal to 100%.

Because it is anchored to flour, the system scales to any batch size and lets bakers compare and adjust recipes precisely (hydration, salt, inoculation) regardless of yield — the universal language of professional formulas.

Baker's Percentage Calculator →Read: What Is Baker’s Percentage? →

Hydration

The water content of a dough expressed as a baker’s percentage of the flour weight.

Hydration governs dough extensibility, fermentation speed, handling, and crumb openness — wetter doughs flow into a more open, irregular crumb but are harder to shape; the optimum depends on the flour’s protein and damaged-starch absorption.

Hydration Calculator →

Total (True) Hydration

The hydration of the whole formula once the water and flour contributed by the levain (and any soaker or preferment) are folded into the totals.

A recipe’s headline hydration can mislead if it ignores the levain’s water; computing true hydration is the only way to compare formulas accurately and to predict real dough feel and crumb.

Hydration Calculator →

Total Dough Weight

The sum of all ingredient weights in a formula, used to scale batches to a target number and size of loaves.

Working backward from desired loaf count and weight (plus a small allowance for baking loss) through baker’s percentages lets a baker derive exact ingredient quantities for any production run.

Baker's Percentage Calculator →

Prefermented Flour Percentage PFF

The share of the formula’s total flour that is fermented in advance within the levain or preferment.

PFF, more than levain weight, predicts fermentation speed and acidity: a higher prefermented fraction means more active organisms and acid entering the final dough, so the bulk runs faster and the loaf tastes more sour.

Baker's Percentage Calculator →

Dough Yield TA, Teigausbeute

A European measure of dough hydration expressed as (flour + water) ÷ flour × 100, so a 65%-hydration dough has a dough yield of 165.

It conveys the same information as hydration in a single figure common in rye and continental baking; higher TA means a wetter, softer dough.

Hydration Calculator →

Scaling

Calculating and weighing out ingredient quantities for a target batch, and dividing bulk dough into equal pieces.

Accurate gravimetric scaling (by weight, not volume) is the foundation of reproducibility — flour packs to wildly different volumes, so only weight gives consistent hydration, fermentation, and loaf size.

Baker's Percentage Calculator →

Mixing & Dough Development

Autolyse

A rest of just flour and water (no salt, no levain) before the main mix, typically 20 minutes to a few hours.

During the rest, water fully hydrates the flour, the gluten begins to organize passively from hydration, and enzymes increase extensibility — cutting required mixing time. It is about hydration, enzyme action, and dough handling — it does not “develop flavor,” since fermentation has barely begun without the culture present.

Fermentolyse

A variant of autolyse in which the levain is included in the initial flour-and-water rest, with only salt held back.

Adding the culture from the start begins acidification and fermentation during the rest, shortening overall timing; salt is still withheld so it doesn’t tighten the gluten before hydration completes.

Related Autolyse·Levain·Salt

Gluten Development

The process of aligning and cross-linking hydrated wheat proteins into a continuous, elastic, gas-holding network.

Mixing, folding, and time encourage glutenin chains to bond (largely through disulfide and hydrogen bonds), turning a shaggy mass into a film that can stretch thin and trap CO2 — the precondition for rise and an open crumb.

Windowpane Test

A check in which a piece of dough is stretched thin; if it forms a translucent membrane without tearing, gluten is well developed.

A clean windowpane shows the gluten network is continuous and elastic enough to trap gas and stretch around expanding bubbles — the practical signal that mixing/folding has done its job.

Stretch and Fold

A development technique of lifting one side of the dough and folding it over, rotating around the bowl, repeated in sets during bulk.

Each fold stretches and re-layers the gluten, building strength and orientation without the heat and oxidation of intensive mixing, while also redistributing temperature and gases — a gentle way to strengthen high-hydration dough.

Coil Fold

A folding method in which the dough is lifted from the center so the ends tuck under, coiling it onto itself, used for slack, gassy doughs.

Coiling builds tension with minimal degassing and minimal handling, making it ideal late in bulk or for delicate high-hydration dough that would deflate under rougher folds.

Lamination

Stretching the dough out to a thin, wide sheet and folding it back onto itself, often once early in bulk.

Spreading the dough thin aligns the gluten across a wide plane and is the easiest point to fold in add-ins (seeds, fruit) evenly; the re-folded layers add structure and can encourage a more open crumb.

Slap and Fold French fold

A hand-mixing technique of repeatedly slapping the dough on the bench and folding it over itself.

The vigorous stretch-and-fold action rapidly develops gluten in wetter doughs by hand, aligning the network quickly without a mixer; it incorporates some air, so it’s used early before the dough is too gassy.

Kneading mixing

Working the dough mechanically or by hand to hydrate flour and develop gluten to a target strength.

Mechanical energy aligns and cross-links gluten and incorporates air, but over-mixing oxidizes the dough (bleaching pigments and flavor) and can break the network down; sourdough often relies on time and folds to reach development with less intensive kneading.

Dough Strength

The overall structural integrity of a dough — its ability to hold shape and trap gas — set by flour, development, and fermentation.

Strength is the balance of elasticity (resistance) and extensibility (flow); too little and the loaf spreads flat, too much and it resists expansion and stays tight. Bakers tune it through flour choice, mixing, folds, and fermentation length.

Extensibility

The dough’s capacity to stretch and extend without tearing.

Extensibility, contributed by gliadin and by enzyme/acid softening, lets dough expand around growing gas cells and lets the baker shape it; too little gives a tight, tearing dough and poor oven spring.

Elasticity

The dough’s tendency to resist deformation and spring back toward its original shape.

Elasticity, contributed by glutenin’s cross-linked network, gives the dough the strength to hold gas and stand tall; balanced against extensibility, it determines whether a loaf is structured or stiff and dense.

Desired Dough Temperature DDT

The target temperature of the dough immediately after mixing, chosen to control fermentation pace (commonly 24–26°C for sourdough).

Fermentation rate is highly temperature-sensitive, so hitting a consistent DDT is the key to reproducible timing; bakers reach it by adjusting water temperature using the friction factor and the room/flour/levain temperatures.

Bulk Fermentation Calculator →

Friction Factor

The temperature rise added to dough by the mechanical energy of mixing, determined empirically for a given mixer and time.

Because friction heats the dough, the baker subtracts it (and the flour, room, and levain temperatures) from the DDT calculation to back out the required water temperature — the missing piece for hitting DDT precisely.

Fermentation Science

Lactic Acid

The dominant, mild-tasting organic acid produced by LAB during sourdough fermentation.

It is favored by warmer (roughly 28–35°C) and wetter conditions and gives the smooth, “yogurt” side of sourdough tang; it lowers pH steadily and, at equal pH, is generally gentler on gluten rheology than acetic acid.

Related Acetic Acid·LAB·Sour·pH

Acetic Acid

The sharper, vinegar-like organic acid produced in smaller amounts during sourdough fermentation.

Its production is favored by cooler temperatures, stiffer (lower-hydration) doughs, longer times, and oxygen availability; heterofermentative LAB make it alongside lactic acid, so manipulating temperature and hydration is how a baker dials sharpness up or down.

Fermentation

The microbial metabolism of sugars by yeast and bacteria, producing gas, acids, ethanol, and aroma compounds.

In sourdough this single process simultaneously leavens (yeast CO2), flavors and preserves (LAB acids), and conditions the dough (acid and enzyme softening of gluten); managing it is the heart of the craft.

Leavening

The aeration of dough by gas that expands it, in sourdough supplied biologically by fermentation.

Leavening gas (CO2) inflates bubbles within the gluten/starch matrix; the network must be developed enough to trap that gas, or it escapes and the loaf stays dense.

Related CO2·Fermentation·Oven Spring·Gluten

Carbon Dioxide CO2

The gas produced primarily by yeast fermenting sugars, responsible for the dough’s rise.

Yeast generate the great majority of leavening CO2 (heterofermentative LAB add a little); it first dissolves into the dough water, then saturates and inflates existing gas cells — which is why new bubbles aren’t created so much as expanded.

Organic Acids

The lactic and acetic acids produced by LAB that acidify the dough and define sourdough flavor.

Beyond taste, acidification lowers pH, which inhibits spoilage and rope bacteria, modulates enzyme activity, strengthens then eventually weakens gluten, and slows staling — the reason sourdough keeps longer than yeasted bread.

Related Lactic Acid·Acetic Acid·pH·TTA

pH

The measure of a dough or starter’s acidity on a logarithmic scale; mature sourdough typically falls near pH 3.5–4.3.

pH reflects the concentration of acid and governs enzyme activity, gluten behavior, and microbial selection, but because it’s logarithmic and buffered it changes slowly late in fermentation — which is why TTA is often the better progress gauge.

Total Titratable Acidity TTA

A laboratory measure of the total acid present in a dough or starter, found by titrating to a fixed endpoint.

Unlike pH (which measures free acid concentration and plateaus), TTA keeps rising as acids accumulate, making it a more sensitive index of how far fermentation has progressed and how sour the bread will taste.

Related pH·Organic Acids·Sour·Maturity

Q10 temperature coefficient

The factor by which reaction (here, fermentation) rate changes for every 10°C change in temperature.

Biological fermentation roughly doubles to triples in rate per 10°C rise within the working range, so small temperature differences translate into large timing differences — the quantitative reason warm dough proofs so much faster and cold retard so dramatically slows it.

Bulk Fermentation Calculator →

Maturity ripeness

The state in which a dough or culture has fermented to its ideal point — fully aerated and acidified but not yet collapsing.

At maturity gas production and gluten strength are optimally balanced; pushing past it (over-fermentation) lets acid and protease degrade the network, while stopping short (under-fermentation) leaves too little gas and flavor.

Over-fermentation overproofing in bulk

Letting fermentation proceed past maturity, so the dough becomes excessively acidic, slack, and gas-depleted.

Prolonged acid and protease action degrade gluten until it can no longer hold gas, and the sugar supply dwindles; the result is a slack, sticky dough that spreads flat with poor oven spring and a dense, sometimes gummy crumb.

Bulk Fermentation Calculator →

Under-fermentation

Stopping fermentation before the dough has developed enough gas, acid, and extensibility.

Too few gas cells and an underdeveloped, tight structure give a dense crumb, tight gas pockets, and frequently a large irregular tear or “flying crust”; flavor is also bland because acids and aromatics haven’t accumulated.

Bulk Fermentation Calculator →

Enzymatic Activity

The collective action of flour and microbial enzymes on starch, protein, and pentosans throughout fermentation.

It supplies fermentable sugar (amylase), softens gluten (protease), and changes water binding — accelerating with warmth, hydration, and time, which is why fermentation, dough feel, and crumb are all temperature- and clock-dependent.

Related Amylase·Protease·Enzymes·Q10

Esters & Flavor Compounds aroma volatiles

The volatile molecules — esters, alcohols, aldehydes, and organic acids — generated by yeast and LAB metabolism that give sourdough its aroma.

Fermentation builds a complex flavor precursor pool (acids and alcohols form fruity esters; amino acids feed later Maillard aromas), so longer and cooler ferments generally deepen flavor — and much of the signature crust aroma forms in the oven from these precursors.

Bulk Fermentation

Bulk Fermentation first rise, primary fermentation

The main fermentation of the whole mass of dough after mixing and before dividing and shaping.

This is where most gas, acid, flavor, and structure develop and where folds build strength; getting bulk right (judged by rise and feel, not the clock alone) is the single biggest determinant of crumb and oven spring.

Bulk Fermentation Calculator →

Target Rise percentage rise

The proportional increase in dough volume used to judge when bulk is complete (often ~30–75% depending on flour, temperature, and process).

Volume increase tracks gas accumulation and fermentation progress far better than a fixed time, because temperature and inoculation change the clock; tying the end of bulk to a rise target makes results reproducible across conditions.

Bulk Fermentation Calculator →

Aliquot Jar Method

Placing a small sample of the same dough in a straight-sided jar to measure its percentage rise precisely.

Because the aliquot ferments under identical conditions to the main dough but in a measurable container, it converts the vague “is it ready?” question into a precise volume reading — the most reliable way to hit a target rise.

Bulk Fermentation Calculator →

Poke Test

Pressing a finger into the dough and reading how the indentation springs back to judge fermentation/proof state.

Springback reflects gluten elasticity versus gas saturation: a fast, full rebound means under-proofed (still elastic, little gas), a slow partial rebound means ready, and no rebound means over-proofed (gluten relaxed, gas-saturated).

Jiggle Test dome/wobble

Gently shaking the container to read how the dough moves and whether its surface has domed and become jiggly with gas.

A dough that wobbles like set custard and shows a domed, bubbly surface has accumulated enough gas and structure to be near the end of bulk; a tight, sloshy, or flat surface signals it isn’t there yet.

Folds During Bulk stretch-and-fold sets

Periodic folding actions performed at intervals through bulk to build dough strength.

Spacing folds through the early-to-mid rise progressively strengthens and aligns the gluten while equalizing temperature and gas, replacing intensive machine mixing with gentle, fermentation-friendly development.

Shaping

Preshape pre-shaping

A gentle first shaping of divided dough into a loose round or log before a rest and the final shape.

Preshaping organizes the dough, builds a baseline of surface tension, and creates a uniform structure so the final shape is tight and even; it also lets the baker adjust strength before committing to the final form.

Related Bench Rest·Final Shape·Tension

Bench Rest intermediate proof

A short rest (15–30 minutes) between preshape and final shape.

The rest lets the tensioned gluten relax (stress relaxation) so the dough becomes extensible enough to shape tightly without tearing — skip it and the dough fights back and rips.

Final Shape shaping

Forming the rested dough into its final loaf geometry with a taut, sealed outer skin.

Final shaping sets the surface tension and internal structure that direct oven spring upward and outward; an even, well-tensioned skin yields a tall, evenly-scored loaf, while a loose or torn one spreads and bursts.

Related Tension·Gluten Cloak·Seam·Boule

Boule

A round loaf shape.

The compact spherical form maximizes height-to-base ratio and is forgiving of slightly weaker dough, making it the classic shape for a tall, open-crumbed sourdough.

Related Batard·Final Shape·Banneton

Batard

An elongated, oval/torpedo loaf shape.

The longer form gives more crust per slice and a directional crumb but demands even tension along its length; uneven shaping shows up as lopsided spring and erratic scoring.

Related Boule·Final Shape·Scoring

Tension surface tension

The taut, stretched state of the dough’s outer skin created during shaping.

A tensioned skin acts like a balloon wall, resisting outward spread and channeling expanding gas upward for height and a good ear; too little tension lets the loaf flatten, too much can restrict spring or tear the surface.

Seam

The closing line where the dough’s edges are joined during shaping.

A well-sealed seam holds the loaf’s structure closed; placed seam-down it stays shut, and placed seam-up (in some methods) it opens decoratively — but an unsealed seam can burst unpredictably in the oven.

Related Final Shape·Tension·Blowout

Gluten Cloak

The tight outer gluten skin developed over the loaf’s surface during shaping.

This continuous, oriented surface layer is what holds tension and gas; building it well is the mechanical key to a loaf that springs tall and scores cleanly rather than spreading.

Related Tension·Final Shape·Oven Spring

Banneton brotform, proofing basket

A coiled-cane or wooden-pulp basket, often rattan, that supports a shaped loaf during its final proof.

It cradles slack, high-hydration dough so it proofs upward instead of spreading, wicks a little surface moisture for a drier skin that scores well, and imprints the characteristic spiral pattern.

Related Final Shape·Proof·Cold Retard

Proofing & Cold Retard

Proof proofing

The fermentation rest of the shaped loaf before baking.

During proof the loaf accumulates the final gas it needs to spring, while the gluten relaxes enough to expand in the oven; judging proof level (under, ideal, over) is critical because it directly sets oven spring and crumb.

Final Proof second rise

The last proofing stage immediately before the loaf goes into the oven.

It is the baker’s last chance to balance gas accumulation against remaining gluten strength; ending it slightly early preserves spring power, since the loaf will continue to expand from oven heat.

Cold Retard retardation

Holding the shaped (or bulk) dough at refrigeration temperatures (~3–6°C) to slow fermentation, usually overnight.

Cold tends to slow the yeast more than the LAB, so acid (and especially acetic-leaning, complex flavor) keeps developing while gas production nearly stops; this deepens flavor, firms the dough for easier scoring, and decouples the bake from the fermentation clock.

Related Acetic Acid·Q10·Final Proof·Esters

Bulk Fermentation Calculator →

Overproof overproofed

Proofing the shaped loaf past its peak, so the gluten can no longer hold gas.

Excess acid and protease relax the gluten and the gas cells coalesce and leak; the loaf shows little or no oven spring, a flat or sunken top, and a dense or coarse, sometimes gummy crumb. (Poke test: indentation does not spring back.)

Underproof underproofed

Baking the shaped loaf before it has fermented enough, while gluten is still very tight.

With too little gas and an over-elastic skin, internal pressure escapes through weak points instead of a clean expansion, producing dense crumb, tight pockets, and often a violent burst or blowout at the side.

Proofing State proof level

The assessed degree of fermentation of a shaped loaf — under-, ideal, or over-proofed — typically read by poke and feel.

It is the immediate predictor of how the loaf will behave in the oven; correctly reading proof state is what lets a baker decide to bake now, wait, or chill to slow things down.

Baking & the Oven

Oven Spring

The rapid final expansion of the loaf in the first minutes of baking.

It is driven by physics, not “yeast working hard”: trapped CO2 and water vapor expand with heat, dissolved CO2 comes out of solution, ethanol and water flash to vapor, and yeast give one last burst of gas before dying around 55–60°C — all before the crust sets and the crumb solidifies. Steam and correct proof let the surface stay extensible long enough to capture it.

Related Steam·Scoring·Crumb Set·Final Proof

Scoring slashing

Cutting the loaf’s surface just before baking to control where it expands.

A deliberate cut creates a weak line so the loaf opens there during oven spring instead of bursting randomly; angle and depth direct the bloom and produce a raised “ear.”

Related Lame·Ear·Oven Spring·Blowout

Lame grignette

A handled razor blade used to score dough.

Its thin, sharp edge slices cleanly through a slack, sticky surface without dragging or deflating it, and a curved blade held at a shallow angle is what cuts the flap that becomes the ear.

Related Scoring·Ear·Oven Spring

Ear

The raised, crisp flap of crust that lifts along a scored cut during oven spring.

It forms when a shallow-angled score creates a flap that the expanding loaf pushes up and outward before the crust sets; a pronounced ear signals good tension, correct proof, adequate steam, and skilled scoring.

Related Scoring·Lame·Bloom·Oven Spring

Dutch Oven combo cooker

A heavy lidded pot used to bake a loaf in a domestic oven.

The lid traps the loaf’s own escaping moisture, creating a steamy microclimate that keeps the crust soft and extensible during oven spring, then is removed to let the crust dry, color, and crisp — reproducing a steam-injected deck oven at home.

Steam in baking

Moisture introduced into the oven during the early bake.

Steam condenses on the cool loaf, keeping the surface moist and elastic so it can expand fully (better spring) before setting; it also gelatinizes surface starches into a thin, glossy, blister-prone skin and delays crust formation so browning is even.

Crust

The dehydrated, browned outer shell of the baked loaf.

As the surface dries past the point where water-dependent reactions stop, heat drives Maillard browning and caramelization that build deep color, aroma, and flavor; crust thickness and color are tuned by steam timing, bake length, and temperature.

Maillard Reaction

The heat-driven reaction between amino acids (from protein) and reducing sugars that browns the crust and generates roasted aromas.

It proceeds rapidly above roughly 140–165°C on the drying crust, producing hundreds of flavor and color compounds; the amino acids and sugars liberated during fermentation feed it, which is why well-fermented dough browns and smells better. (It is distinct from caramelization, which is sugar alone.)

Caramelization

The thermal breakdown of sugars (no amino acids involved) at high temperature, contributing crust color and sweet-bitter notes.

It begins around 160°C and above, alongside but chemically separate from the Maillard reaction; together they create the full crust color and flavor, with caramelization contributing the sugary, slightly bitter top notes.

Related Maillard Reaction·Crust·Starch

Crumb Set setting / starch gelatinization in bake

The point in baking where the expanded crumb solidifies into a stable structure as starch gelatinizes and proteins coagulate.

Once the internal temperature climbs (starch gelatinizes roughly 55–75°C, proteins set above), the soft foam locks into a sliceable solid; this is why a loaf pulled too early collapses and why oven spring ends when the crumb sets.

Bake-Through / Internal Temperature

Baking until the loaf’s center reaches a temperature indicating the crumb is fully set (about 96–99°C for lean sourdough).

The center must get hot enough to complete starch gelatinization and drive off excess moisture; an under-baked center stays gummy and pasty, so internal temperature (or a long enough bake) is the reliable doneness check.

Baking Stone / Baking Steel

A preheated slab of stone or steel that the loaf bakes on.

Its stored heat and (for steel) high conductivity deliver a strong burst of bottom heat that boosts oven spring and crisps the base, compensating for the weak, fluctuating heat of a domestic oven.

Related Dutch Oven·Oven Spring·Crust

Crumb & Evaluation

Crumb

The internal cellular structure of the baked loaf — its network of walls and gas holes.

Crumb is the visible record of the whole process: gas production, gluten strength, shaping tension, proof level, and bake all leave their mark in cell size, evenness, and wall texture, making it the baker’s main diagnostic.

Open Crumb

A crumb with large, irregular, glossy gas holes and thin cell walls.

It results from the combination of higher hydration, strong-but-extensible well-fermented gluten, gentle handling that preserves gas, and good oven spring; it is an aesthetic and textural goal, not inherently “better” bread, and is harder with whole-grain flours.

Hydration Calculator →

Tight Crumb closed crumb

A crumb with small, even, regular cells and thicker walls.

It comes from lower hydration, more degassing, whole-grain flours, or shorter fermentation; far from a fault, it is preferred for sandwich and rye breads where structure and even slicing matter more than large holes.

Gelatinization starch gelatinization

The irreversible swelling and gelling of starch granules when heated in the presence of water (roughly 55–75°C for wheat).

It is a purely physical/thermal process — starch + water + heat — that sets the crumb’s final structure in the oven; it is not a fermentation phenomenon, and incomplete gelatinization (under-baking) leaves a wet, gummy crumb.

Gummy Crumb gumminess

A dense, sticky, paste-like crumb that gums up when chewed or cut.

It usually means starch never fully set or stayed water-logged — from under-baking (incomplete gelatinization), excessive amylase/damaged starch, or severe over-fermentation that degraded structure; slicing while still hot can also mimic it because starch retrogradation isn’t complete.

Gum Line

A dense, often translucent band of compacted crumb just beneath the top crust.

It typically forms when the crust sets and seals before the interior has fully baked and released moisture, or when an underproofed/over-degassed loaf collapses its upper cells; it signals a mismatch between crust and crumb setting, often fixed by more steam, lower top heat, or a longer bake.

Blistering

The small bubbles on the crust surface, prized as a sign of a well-fermented, well-retarded loaf.

Blisters form when gas bubbles just under the skin expand against a steam-softened surface in the oven; cold retarding raises surface gas and the right moisture lets them push up and set, so heavy blistering correlates with cold-proofed, mature dough.

Related Cold Retard·Steam·Crust·Oven Spring

Bloom

The opening and lift of a score during baking, together with the resulting color and sheen of a well-sprung crust.

A good bloom shows the loaf had enough gas, tension, extensible surface, and steam to expand through the cut before setting; it is the visible payoff of correct proof and scoring.

Related Ear·Scoring·Oven Spring·Steam

Gluten Window

The thin, translucent membrane a piece of well-developed dough forms when stretched (the result the windowpane test looks for).

Its translucency and resistance to tearing demonstrate a continuous, properly cross-linked gluten film capable of trapping gas — the structural prerequisite for both rise and an open crumb.

Equipment & Tools

Bench Knife scraper, dough scraper

A flat-edged metal or plastic tool for dividing, lifting, and shaping dough.

It lets the baker handle slack, sticky high-hydration dough with minimal sticking and degassing, dividing cleanly and building tension during shaping where hands alone would tear or deflate it.

Related Scaling·Preshape·Final Shape

Dough Thermometer

An instant-read probe used to measure dough, water, and finished-loaf temperatures.

Because fermentation rate is so temperature-sensitive (see Q10), measuring dough temperature to hit DDT and checking internal temperature for doneness are the two cheapest ways to make sourdough reproducible.

Bulk Fermentation Calculator →

Kitchen Scale

A gram-accurate digital scale for weighing ingredients and dough.

Baker’s percentages and consistent hydration are only possible by weight; volume measures of flour vary by 20% or more with packing, so the scale is the foundation of repeatable formulas.

Baker's Percentage Calculator →

Proofing Box proofer

A temperature-controlled enclosure that holds dough at a set fermentation temperature.

By fixing temperature it removes the biggest source of timing variability, letting a baker reproduce the same fermentation pace and acid balance year-round regardless of kitchen conditions.

Bulk Fermentation Calculator →

Couche baker's linen

A heavy linen cloth used to support and separate proofing loaves, especially baguettes and batards.

Pleated between loaves, it holds their shape and tension during final proof and wicks surface moisture for a skin that scores and blooms cleanly, much as a banneton does for rounds.

Related Banneton·Final Proof·Batard

Faults & Troubleshooting

Dense Crumb

A heavy, close, poorly-aerated crumb lacking adequate rise.

It points to too little effective leavening — a weak or unripe starter, under-fermentation, weak gluten that failed to trap gas, or excessive degassing; diagnosing which requires reading the whole process, not just the loaf.

Bulk Fermentation Calculator →

Flat Loaf spreading

A loaf that spreads sideways with little height.

It usually means the dough couldn’t hold its structure — from over-fermentation/overproof (degraded gluten), too-weak flour, excessive hydration without strength, or insufficient shaping tension; the fix targets whichever of structure or fermentation failed.

Bulk Fermentation Calculator →

Slack Dough

Dough that is loose, soft, and unable to hold its shape.

Slackness comes from under-development, over-fermentation (acid/protease breakdown), too much water for the flour’s strength, or insufficient salt; identifying the cause is what separates “add structure” from “ferment less” as the remedy.

Hydration Calculator →

Blowout burst

An uncontrolled rupture of the loaf side or base during baking.

When a loaf is underproofed or poorly scored, expanding gas can’t escape through the intended cut, so internal pressure forces an opening at the weakest point — usually an unsealed seam or shallow/absent score. More proof, deeper scoring, and a sealed seam prevent it.

Related Underproof·Scoring·Seam·Oven Spring

Pale Crust

A crust that stays light-colored despite adequate baking time.

Browning needs residual sugar for the Maillard reaction; over-fermentation can exhaust the fermentable sugars, low-enzyme flour can fail to supply them, and too little heat or too much lingering steam suppresses browning — so a pale crust is often a fermentation or sugar-availability clue, not just an oven setting.

Too Sour excess sourness

A loaf whose acidity overwhelms the other flavors.

Excess acid builds from long, warm, or high-inoculation fermentation and from an over-acidic, infrequently-fed starter; to reduce it, ferment cooler and shorter, lower inoculation, feed the starter more often, and use it nearer its peak rather than past it. (Note: cool retard raises acetic sharpness even as it slows overall acid buildup.)

Flying Crust / Detached Crust

A gap where the top crust separates from the crumb, which sinks away beneath it.

It is a classic underproofing/under-fermentation sign: the surface sets and springs while the under-fermented interior lacks the gas to fill the space, so the crumb pulls away. More fermentation and proof close the gap.

Bulk Fermentation Calculator →