What is True Total Hydration in sourdough baking?

True Total Hydration measures the total water in the entire dough matrix (including the water contributed by your starter) divided by the total flour weight. Conventional calculators ignore starter water, resulting in dough that is 2.7% to 3.0% wetter than intended.

Why does adding 20% starter increase hydration by ~3%?

A standard 100% hydration levain consists of 50% flour and 50% water. When you add 100g of levain to a recipe with 450g flour and 315g water (70% apparent hydration), the total flour becomes 500g and total water becomes 365g. 365 / 500 equals 73.0%—a full 3 percentage points higher.

What is Desired Dough Temperature (DDT) and why does it matter?

DDT is the target dough temperature right after mixing (typically 76°F / 24.4°C). Temperature governs yeast metabolism and enzymatic activity. Controlling water temperature ensures bulk fermentation finishes at the predicted time without under- or over-proofing.

How does ice substitution work when DDT calculates a temperature lower than tap water?

In hot kitchens, the required water temperature may fall below what your cold tap can deliver. By replacing a portion of water with crushed ice, the phase change absorbs 80 calories per gram of latent heat of fusion, cooling the dough without adding excess liquid.

Why does whole wheat flour absorb more water than bread flour?

Whole wheat flour retains the fibrous outer pericarp (bran) and germ. The insoluble fibers and pentosans in wheat bran act like micro-sponges, absorbing up to 200% of their own weight in water.

What do starter feeding ratios (like 1:2:2 or 1:5:5) actually mean?

A feeding ratio denotes the proportional weights of [Seed Starter : Fresh Flour : Water]. For example, a 1:2:2 ratio means 1 part starter inoculated into 2 parts flour and 2 parts water (e.g., 20g starter + 40g flour + 40g water = 100g total yield).

Why is the float test unreliable for judging sourdough starter readiness?

The float test merely confirms that trapped gas pockets render the sample less dense than water. An over-fermented, highly acidic starter with a degraded gluten mesh can still float, yet will produce poor oven spring because its gluten-degrading enzymatic activity is already past its prime.

How do higher feeding ratios (1:5:5 or 1:10:10) affect sourdough flavor?

Higher feeding ratios dilute accumulated acetic and lactic acids, granting wild yeasts an abundant food supply to multiply vigorously before bacteria produce strong acidity. This produces a sweeter, milder flavor profile with explosive oven spring, ideal for open crumb sourdough and panettone.

How do I know when my starter has reached its true peak?

A mature starter reaches true peak when its volume has doubled or tripled, its top surface forms a convex dome, the glass jar shows active webbed bubbles, and its aroma is pleasantly fruity and lactic rather than sharp, nail-polish-remover acetone.

Sourdough Starter Feeding Calculator & Peak Timing Forecaster

Standard Operating Procedure (SOP): Judging True Levain Peak

In sourdough baking, timing your dough mix to coincide precisely with your levain's peak biological vitality determines whether your bread displays a soaring oven spring or collapses into a heavy, gummy loaf. A levain mixed into the autolyse before peak suffers from deficient yeast populations; a levain mixed past peak introduces proteolytically degraded gluten and excessive acetic acidity into your bulk ferment.

Myth Busted: Why You Should Stop Relying on the "Float Test"

The ubiquitous "float test"—dropping a spoonful of starter into water to see if it floats—measures nothing more than bulk density relative to water. Trapped CO2 bubbles cause starter to float even when it has begun collapsing, proteolyzed its own gluten matrix, and accumulated toxic acid levels.

Conversely, a 100% whole rye or whole wheat starter that is brimming with active yeast may sink immediately because fibrous bran particles interrupt surface tension. Relying on physical visual cues in the jar is far more scientifically sound.

Physical Morphology of a Peak Starter vs Over-Fermented Levain

Fermentation Phase	Surface Curvature	Internal Aeration	Olfactory Profile	Baking Suitability
Pre-Peak (Rising)	Strong convex dome; rising up jar walls	Dense, small pinhead bubbles	Sweet flour and mild fresh milk aroma	Too early; yeast cell counts not yet maximized
TRUE PEAK (Optimal)	Convex dome at maximum height; zero cratering	Massive elongated chambers with gluten webbing	Fragrant green apple, sweet yeast, and yogurt	PERFECT: Maximum gas output and gluten integrity
Post-Peak (Cratering)	Center has sunken concave; dark streak lines on glass	Bubbles popping; frothy liquid layer	Sharp vinegar, solvent, or acetone notes	Degraded; gluten enzymes weaken dough structure

Strategic Feeding Ratio Selection (1:1:1 vs 1:2:2 vs 1:5:5)

Manipulating your feeding ratio allows you to dictate when the starter reaches peak maturity, fitting sourdough maintenance seamlessly into your daily lifestyle:

1:1:1 InoculationPeak Window: 4 - 5 hours

Equal parts starter, flour, and water. Best for morning prep when you want to mix your dough by early afternoon on the weekend.

1:2:2 InoculationPeak Window: 6 - 8 hours

The artisan standard. Dilutes acidity sufficiently to allow yeast cells to multiply steadily without premature enzymatic breakdown.

1:5:5 InoculationPeak Window: 10 - 12 hours

Overnight workhorse. Feed before going to sleep at 10:00 PM; your levain will be at its glorious peak when you wake up at 8:00 AM.

Frequently Asked Questions on Starter Feeding Ratios

What flour blend is best for feeding sourdough starter?

A 50/50 blend of unbleached bread flour and whole rye (or stoneground whole wheat) provides the optimal substrate. Whole rye supplies ample amylase enzymes and mineral ash to fuel fermentation, while strong bread flour supplies the gluten elasticity needed to trap CO2 and display obvious volume rises.

Do I need to discard starter at every feed?

Yes. If you do not discard down to the specified seed starter weight (e.g. 20g for a 100g total yield), the required flour and water to maintain a healthy 1:2:2 ratio would grow exponentially, resulting in liters of wasted flour within days. Save your discard in the fridge for pancakes, crackers, and waffles!