Vol. XXIV · Bread Plate 6 of 12desired dough temperature, DDT, water temperature, friction factor, bulk fermentation, cold retard, overnight dough, refrigerator, flavour, schedule, 发酵时间TH

Time and Temperature.

The same dough rises in an hour and a half at 26 °C and takes all night in the fridge. The baker chooses which by setting the water temperature.

Because yeast and enzymes depend so steeply on temperature (XXIV.5), a baker who wants predictable timing controls the dough's temperature, not just the clock. The method is the desired dough temperature (DDT): pick a target, typically 24–26 °C for lean doughs; measure the flour and the room; add the warming caused by mixing (the friction factor — a few degrees by hand, ten or more in a fast mixer); then set the water so the four average to the target. The formula is exact bookkeeping of heat: water temperature = 3 × DDT − (flour + room + friction).

Once mixed at the right temperature, the bulk fermentation follows a known course. Bakers can also stretch it: a cold retard — the dough or the shaped loaves held in the fridge at 3–5 °C for 8–48 hours — slows yeast almost to a halt while enzymes and bacteria keep producing flavour and the crust browns better from the extra sugars freed (VIII.3). It also lets bread be shaped one evening and baked the next morning. The workshop sets the water.

Below: the water temperature that gives the desired dough temperature you choose, from the flour and room temperatures and the mixing method (exact DDT bookkeeping), and the time the dough then takes to double at that temperature (course fermentation model, 1 % instant yeast).

What you will learn
Workshop
DDT method: water = 3 × DDT − (flour + room + friction), exact for equal-weight averaging as bakers use it. Friction: about 4 °C for hand mixing, 12 °C for a stand mixer (typical values). Doubling: course fermentation model with 1 % instant yeast at the DDT.

Set the water, then trust the clock

For a 25 °C dough with flour at 20 °C in a 22 °C kitchen, mixed by hand, the water should be about 29 °C. In a 30 °C summer kitchen with warm flour and a stand mixer, it falls to about 5 °C — iced water — which is how bakeries keep their doughs from racing in summer. A dough held at 4 °C rises only to about 1.12 times its volume in twelve hours with 1 % yeast, and to 1.14 in a day with 0.5 %: the cold retard pauses it while flavour develops.

A workable home schedule: mix in the evening with water at the DDT temperature and 1 % yeast; bulk-ferment 1–2 hours with two sets of folds (XXIV.4) until about 1.5 times its volume; shape; refrigerate overnight in a floured basket; bake straight from the fridge in the morning, scoring the cold, firm dough cleanly (XXIV.8). Use a probe thermometer to check the dough after mixing; if it is off by more than a degree or two, adjust the next batch's water and expect the rise to be faster or slower accordingly.

At the stove

Next time you mix bread, measure the flour and room temperature, calculate the water for a 25 °C dough, and check the mixed dough with a thermometer.

The friction factor is a craft measurement: bakers find their own by mixing a dough, measuring its temperature, and solving the DDT formula backwards — each mixer, speed and dough has its own.

Terms

Desired dough temperature (DDT)
The target temperature of a freshly mixed dough.
Friction factor
The warming caused by mixing.
Bulk fermentation
The first rise of the whole dough before dividing.
Cold retard
Slowing fermentation in the fridge for flavour and timing.
Control fermentation by temperature: water = 3 × DDT − (flour + room + friction). At 24–26 °C a lean dough doubles in an hour or two; a cold retard slows it overnight for flavour and convenience.

Sources

  1. A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
  2. H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.