What temperature should my water be?

A dough’s temperature off the mixer largely sets how fast it ferments, so a schedule only holds if the dough starts near its intended temperature. Water is the one ingredient whose temperature you can easily choose: water temperature = target × number of factors − (flour + room + friction [+ preferment]).

Water temperature

27 °C

(24 × 3) − (20 + 21 + 4) = 72 − 45 = 27 °C

Measured your dough after mixing? (°C, optional)

Mix with the water above, probe the dough, and enter its temperature to work out your own friction factor.

Yeast conversion

Active dry yeast: 2–3 g

Fresh (cake) yeast: 6 g

Fresh yeast is used at about three times the weight of instant. Between instant and active dry, sources disagree — King Arthur and Red Star treat them as 1:1, many recipes use up to about 1.5× as much active dry — so the range shows both. These ratios are practical baking approximations, not exact conversions. Actual required quantity varies with product age, storage, and manufacturer. When in doubt, use the lower end and extend fermentation time rather than the reverse.

How this works

The desired-dough-temperature method treats each heat source in the mix — flour, room, the friction of mixing, a preferment if there is one, and the water — as contributing roughly equally to the final dough temperature. Knowing all but the water, it solves for the water.

The friction factor is the heat added by mixing, and it is the least certain input: it depends on the mixer, the speed, the time and the batch size. The presets are illustrative figures converted from King Arthur's measurements; the reliable figure is your own, which the tool works out from one measured batch.

Yeast conversion is shown as a range where sources disagree, rather than a single number that hides the disagreement.

Formulas

Straight dough: water = (target × 3) − (flour + room + friction)
With a preferment: water = (target × 4) − (flour + room + preferment + friction)
Your friction factor: friction = (measured dough temperature × 3) − (flour + room + water)
Fahrenheit friction to Celsius: °C difference = °F difference × 5 ÷ 9
A friction factor is a difference, so there is no 32° offset.

Assumptions

Each factor counts equally. Ingredients actually differ in mass and heat capacity, which is why the method is a good estimate rather than an exact answer.
Temperatures are in the same unit throughout; the tool converts Fahrenheit for you.

Limitations

A very low result means you need ice or cold flour; a very high one means warming the room or flour instead — the tool says so rather than hiding it.
Yeast products vary by manufacturer, age and storage; judge the dough rather than the clock.