I don’t do a lot of baking but I enjoy watching videos.
One common element in baking is you make the dough and then set it aside so the yeast can make it rise. When it’s approximately doubled in size, you take it out and press it down so it deflates.
I’ve never understood the underlying logic here. Why do you deflate it right after giving it a rest period to inflate?
What would happen if you just took the dough and put it in the oven to bake without deflating it? Would there be huge air bubbles inside the resulting bread?
On the other hand, what would happen if you skipped the inflate/deflate process? Just mix the dough and then immediately use it without the rest period?
You’d have a smaller number of larger air bubbles (well, CO2, but you get the idea). By punching it down, you deflate all the bubbles that were created while the yeast was busily multiplying like mad. You then give it another chance to rise, and the many more yeast cells don’t have to make as much gas, individually, as there are more yeast cells doing the work, so you end up with more, smaller bubbles.
If you just mixed it and baked it, you’d have what would realistically be an unleavened bread, with the consistency of a paving stone.
Not all recipes want you to deflate your dough in between rises. My ciabatta recipe directs me to preserve as much of the CO2 from the first rise as I can as I shape the loaves for the second rise. The second rise isn’t much of a rise at all, more of a rest period. But the dough sure jumps up with oven spring as soon as I bake it.
The yeast needs time to prove and the dough must hydrate, allowing flour and water to develop structure. Even if you don’t deflate your dough in between rises, it’s good to let it rise twice. Even no-knead recipes – which also want you to preserve as much of the CO2 between rises and not knock down your dough in between – will allow for a brief rest period before baking.
Alton Brown refers to the “punch-down” step as “redistribution”. During that first rise, you’ll have a lot of big bubbles, and that makes for horrible bread texture. Ever been making a sandwich, and you pull out a slice of bread, and there’s a big empty space in it caused by a large bubble that got baked in? You don’t want that.
So you punch down. Basically, you’re just “redistributing” the gas that the yeasties have blown out, spreading it throughout the dough. It’s easier for yeasts to add a little bit of gas to a bubble that’s already started instead of starting one of their own. By redistributing, you get a lot of small bubbles instead of a few big nasty ones, and a nice fine bread texture.
Maybe, like a loaf of unleavened bread, I’m just being dense. But why does the yeast produce big bubbles on the first rising and not on the second rising?
Wouldn’t this cause bigger bubbles in the second rising? That’s when the yeast has bubbles from the first rising to add gas to. During the first rising, there were no existing bubbles, so the yeast had to start new bubbles.
It could be that the gluten is more developed for the second rise, and better at trapping the bubbles before they all merge together. I have also read that bubbles need a ‘seed’ to form around, so redistributing the air gives them more places to form.
Another reason for punching down is to protect the gluten. (Gluten is the protein that gives bread it’s structure. It forms long strands that hold the bread up, so to speak). If you let the bread rise for too long, the gluten strands will get overstretched, and break. Two rises gives the yeast more time to produce flavour, so you punch down in between.