Jimbtv? New Oven = Outrageous Oven Spring

Going back to the basics of hearth baking, the hearth is often heated to in excess of 700 F during the firing period. When a loaf of proofed bread is placed on that hot surface the gases inside the dough expand. We all know that. Hearth ovens usually do not incorporate steam because the rate of expansion is so fast that the crust doesn't have a chance to set before the expansion (oven spring) is complete.

Conversely, if we put that same proofed loaf in a 400 F oven it is going to take a longer time for the gases to expand. The crust will take longer to form as well but the crust will set enough to inhibit expansion sooner, and that is part of the reason we incorporate steam.

Another way to coax a rapid expansion is to use an oven with a sealed baking chamber and set the top heating elements 25 - 50 degrees cooler than the bottom elements. My new oven offers me that feature and temperature probes and displays from top and bottom locations verify the differential. Placing the proofed loaf on the hot deck will encourage a vertical heat transfer - heat trying to rise to the cooler air above. What I am seeing is a fairly rapid vertical growth of the loaf, more so than I experienced in my gas-fired Blodgett deck oven.

Of course I am incorporating steam too but now it is a single 2 second blast that lives in the chamber until I vent it overboard. My steaming times are being adjusted downward as well. What used to be 10 minutes of steam is now around 5 minutes. I could probably get away with dropping it down to 3 minutes but I am still learning. My 20 minute steam time is now down to 10 minutes, and I think I'm still on the fat side of the curve.

Right now I am having some challenges with my baguettes because of this rapid expansion. I never had trouble with large bubbles forming with my Blodgett but now a good number of my baguettes are forming large bubbles just under the scoring lines. I originally thought that I was getting sloppy on my degassing but I have been paying special attention and still getting the bubbles. One bonus is that the rest of the baguette is showing a really impressive open crumb. That was hit-and-miss with the Blodgett. Now it is consistent with the Doyon but apparently too much of a good thing, resulting in big bubbles.

We are not at critical mass on the baguettes and I enjoy the challenges of learning how to dial things in. Everything written in this note is my personal experience and could all be scientific bunk, but I'm sticking with it until someone proves me wrong :-)

So, what I am learning is that HOW you manage heat in the baking chamber has a big effect on the end product. This isn't to imply that a wonderful loaf of bread cannot be baked in a home oven. It can be done - I've done it. But like an artist moving from cheap brushes, oils and canvases to the pro-grade stuff, I am afforded more control over the nuances of the creative process. Thus far I am enjoying the journey.

Dan,  I don't have a BGE, but have a kamado cooker. While the BGE will get the stone hot enough, when you spray steam in through the top vent, it will likely come right back out.  IIRC,  if you close off the top vent, it cuts down on the combustion.