What happens when you cook bread in a microwave? This was the question that started this experiment. And you are indeed cooking the bread, you are not baking it, which is what occurs in a hearth oven. Although technically a microwave is an oven, it doesn’t bake, it cooks.
What I wanted to replicate was what is called an “oven-spring” which is the quick expansion a dough should go through in a hot oven in order to become enlarged and stretch out the dough to make the crumb light and filled with pockets. Those pockets in the crumb, depending on the bread, the larger and more irregular they are, the better.
Now, what would happen if you took the oven spring and sped it up ten times faster? The result is in the picture above and below. We used a regular lean dough with a poolish as a pre-ferment. We use this dough regularly for baguettes. So it is a strong dough with sufficient gluten development. But I wasn’t sure if the gluten would withstand such a quick expansion without ripping.
The dough was placed in a cryovac bag and sealed, without vacuuming the air out. So it was just a pouch. This sped up the fermentation process, since the heat that was generated by the yeast activity was concentrated in a closed environment. After about one hour of proofing the dough, we made two air holes in the cryovac bag, placed it in the microwave, turned it on to high and set the dial to two minutes.
Within seconds the dough began to expand, and by the 45 second mark it had expanded to twice the size. I could still see it bubbling in the bag, which to me meant that the protein had not fully coagulated yet (the bread wasn’t cooked all the way), so I let it go the full two minutes until it stopped bubbling. There is a point in the dough when the gluten expands enough in relation to how fast it is coagulating, that the strands cannot expand any further, so the growth and enlargement is stopped. The problem with a microwave is that it will not produce a firm crust. It is soft like white bread. Because what is really happening in the bag is that the dough is getting cooked two way: through the microwave electromagnetic radiation and through the steam from the moisture that is in the dough itself, which is much a more violent steam bath than it would be in a regular steamer.
We immediately placed the bread in a hearth oven, steamed it and finished baking it until it had formed a beautiful dark brown crust.
The result was a perfectly acceptable loaf of bread. The shape was not ideal (it was shaped like the bag it had been cooked in), but the crumb was spot on as you can see, and crust was crusty.
This is not to say that we are going to change the way we make bread. Not at all. We just know how to make it another, non-traditional way, with excellent results.