Loaf 4: yeast takes over the lift

This is Loaf 4 of 16. One thing changed from Loaf 3: the baking powder came out and 6 g of instant yeast went in. The formula is otherwise identical, and hydration is still 60%.

This is the loaf the sugar had to leave for, and the order of Loaves 3 and 4 is the one piece of sequencing in this course that cannot be swapped.

The four things that never move

400 g flour, 8 g salt (2%), one 9 x 5 inch (23 x 13 cm) loaf pan, 375°F / 190°C. The oven setting does not change just because the loaf now rises on the counter first.

The formula

Hydration: 60% (240 g water on 400 g flour)

Method

1. Stir the flour, salt and yeast together dry.
2. Add the water (lukewarm, 80 to 90°F / 27 to 32°C), the eggs and the oil. Stir with a sturdy spoon for 2 minutes until no dry flour remains. Do not knead. It looks rough and that is correct.
3. Cover the bowl. Leave at 75°F / 24°C until the gate below, usually 1½ to 2 hours.
4. Stir it down, scrape it into the greased pan, level the top.
5. Second rise, covered, at 75°F / 24°C, about 45 minutes, until it has climbed to about ¾ inch / 2 cm below the rim.
6. Bake at 375°F / 190°C for 40 to 45 minutes. Cool at least 1 hour.

Why this works

Baking powder makes gas by chemistry. It fires when it gets wet, it fires again when it gets hot, and then it is finished. Yeast is alive. It eats sugars in the flour and makes gas biologically and continuously, for as long as you leave it warm and fed. That difference in timing is why this loaf needs two rises instead of none.

But gas is not the reason yeast is in the course. While it works, yeast also produces alcohols and acids, and those are flavor. This is the first loaf that tastes of something nobody poured into it. Loaves 1, 2 and 3 tasted like their shopping lists, and Loaf 3 tasted like almost nothing, which was the point. From here the loaf starts making its own.

Why the sugar had to leave first

Loaf 2 carried 164 g of sugar, which is 41% of the flour weight. Sugar dissolved in water pulls water toward itself, and so away from anything else that wants it, including the yeast cells. A yeast cell in a heavily sugared dough loses water across its own wall and spends its energy fighting that instead of fermenting. Bakers call it osmotic stress, and it is the same reason a salted vegetable weeps.

The numbers are not subtle. Yeast activity falls off noticeably from about 10% sugar on flour weight, and commercial bakeries switch to special osmotolerant strains, meaning strains bred to tolerate exactly this, once a dough is genuinely sweet. Research on high-sugar doughs shows the pattern directly: as sugar climbs, the yeast consumes less sugar, produces less carbon dioxide and delivers lower loaf volume (Sugar levels determine fermentation dynamics during yeast pastry making, Osmotolerant yeast, BAKERpedia).

Ordinary instant yeast in a 41% sugar batter would make very little gas, slowly. That version would bake a brick, and every loaf in this course is one you actually eat. So the sugar goes first, and the yeast walks into a dough that will let it work.

How you know it's ready

The bulk rise is the new gate, and it is a look, not a clock. The dough has risen by half, it is domed, and a wet fingertip pressed into it leaves a dent that fills back slowly rather than snapping shut. Not doubled. Half.

At 75°F / 24°C that is usually 1½ to 2 hours, and that is the usual, not the rule. A cooler kitchen takes longer. A recipe that just says two hours is describing its own kitchen, not yours.

The second rise is done when the dough has climbed to about ¾ inch / 2 cm below the rim, about 45 minutes at 75°F / 24°C.

The bake is done when the center reads 200 to 205°F / 93 to 96°C, usually 40 to 45 minutes at 375°F / 190°C. That is a shorter bake than Loaves 1 through 3 took, because this is a risen dough rather than a poured batter.

What goes wrong

The failure this loaf introduces: a brick that barely rose at all.

One cause: water hot enough to kill the yeast.

Anything above about 120°F / 49°C does it, and hot from the tap in a lot of houses is hotter than people think. Yeast that went in dead does not recover, and no amount of extra rising time brings it back, so the dough sits in the bowl never reaching the gate and then bakes dense.

The fix is the wrist test. Use water that feels barely warm on the inside of your wrist, which puts you in the 80 to 90°F / 27 to 32°C the method asks for. If you have a thermometer for the bake, use it here too.

When it worked

Taller than Loaf 3, with a rounded top. The crumb is even, small and slightly chewy rather than crumbly. It is still soft and rich, because the egg and the oil have not gone anywhere yet.

And it smells like bread. That is the moment this loaf exists for.

Bake it twice before you move on to Loaf 5, where the egg comes out. One good loaf is luck. Two in a row is a skill.