After 6 to 8 hours, mix the 740 grams of white flour and the 60 grams of whole wheat flour by hand in a 12-quart round tub. Add the 620 grams of 90°F to 95°F (32°C to 35°C) water and mix by hand just until incorporated. Cover and let rest for 20 to 30 minutes.

SAMPLE SCHEDULE: Mix at 7 p.m., shape into loaves at 8 a.m. the next morning, and bake at 9:15 a.m. The bread will come out of the oven a little after 10 a.m.

If you want an even chewier crust, leave the loaves in the oven with the door partly open for a few minutes after turning off the oven.

At my bakery, we use a levain with hydration close to that of the final dough it will be used in. I find this approach more balanced, as opposed to mixing in a levain with a substantially different hydration than the dough. The result is bread in which you can taste the wheat, the fermentation, and a subtle chorus of lingering background notes that

think you will find it satisfying to know you have the recipe format down and can make flour changes to suit your taste (or just to use what you have available). The most important thing is to stick with the same total amount of flour in the recipe, since amounts of all the other ingredients are based on ratios to the total flour weight.

The best way to start a levain is to use whole grain flour: whole rye, whole wheat, or a combination of the two. Rye flour doughs are sticky and way more difficult to rinse off your hands than wheat flour doughs, so you’ll find it easier to start a levain with whole wheat flour than with whole rye flour. But if whole rye is what you have or what

Because bulk fermentation and proofing time are relative to the amount of leavening and the temperature the dough is held at, you can use those variables to give yourself more time. Note that I don’t advocate speeding up fermentation or proofing, as this can adversely affect quality.

Salt Salt delays the fermentation process, and while some good bakers use salt in their levain culture, I prefer not to, as I’m looking for active development. (Still, certain environments or schedules necessitate the use of small amounts of salt.)

Temperature and time have an inverse relationship, and I like the visual image of a seesaw to communicate the need for balance between the two: more of one means you need less of the other. A warm dough develops more quickly, whereas a cooler dough develops more slowly. Specifically, dough temperature affects the metabolic rate of the yeast: warmer