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.

King Arthur vs. Bob's Red Mill vs. Bread Flour: Absorption Limits Tested

The Structural Difference: Proteins, Damaged Starches, and Pentosans

Why can dark rye flour absorb up to 110% water while all-purpose flour turns into batter past 72%? The answer lies in the biochemical composition of the grain.

The 5 Flour Categories & Their Absorption Ceilings

Flour Variety	Protein %	Primary Absorption Mechanism	Recommended Base Hydration	Maximum Hydro-Ceiling
King Arthur Bread Flour	12.7%	High glutenin/gliadin ratio, strong disulfide cross-linking	65%	82%
Bob's Red Mill Artisan Bread	13.5%	Hard red spring wheat, robust gluten matrix	66%	84%
Unbleached All-Purpose	10.5% - 11.7%	Moderate protein; prone to protease degradation	60%	72%
Stoneground Whole Wheat	13.5% - 14.5%	Bran flakes act as micro-sponges absorbing 2x their weight	80%	92%
Dark Rye (Secale cereale)	9.0% - 11.0%	Arabinoxylans (pentosans) form viscous hydrocolloids	95%	110%

The Whole Wheat Paradox: High Protein but Fragile Gluten

Many beginners see "14% Protein" on a whole wheat flour bag and assume it will form a bulletproof gluten sheath. In reality: - Whole wheat includes the sharp pericarp (bran flakes), which act like microscopic razor blades physically severing the gluten strands during coil folds. - The germ contains glutathione, a natural reducing agent that cleaves disulfide bonds. - **The Solution:** Compensate with a longer initial autolyse (60 minutes) to allow the bran to thoroughly soften and saturate before introducing the acidifying levain.

Calculating Multi-Flour Weighted Hydration

When formulating an artisan blend (e.g. 75% Bread Flour + 20% Whole Wheat + 5% Rye), SourdoughCalc automatically computes the weighted average baseline:

\text{Recommended Baseline} = (0.75 \times 65\%) + (0.20 \times 80\%) + (0.05 \times 95\%) = 48.75\% + 16.0\% + 4.75\% = \mathbf{69.5\%}

This ensures you push hydration right up to the structural limit without tipping over into a sticky, unmanageable dough puddle.

The Structural Difference: Proteins, Damaged Starches, and Pentosans

The 5 Flour Categories & Their Absorption Ceilings

The Whole Wheat Paradox: High Protein but Fragile Gluten

Calculating Multi-Flour Weighted Hydration

Ready to test this formula with your flour blend?