Debug the Bread

Hello Oliver,

I wonder whether you have trapped some large bubbles of air during shaping that have not resealed during proving.  This can be caused by having too much flour about that forms a coating that does not allow the dough to re-weld properly and when it goes into the oven the expansion of the air creates the big bubble.

So one possibility is to try using less flour during the shaping procedure.  The other is to check the loaf for any large bubbles after shaping  (and after proving) and just prick them with a skewer to deflate them.

Hope this helps.

Farinam

 When you shape your loaves are you making sure that the skin of the dough is tight?

I have had the same in the past and I use an almost identical recipe to you (66% hydration. 30% wholemeal/70% white. 1.4% salt). To solve the problem I now shape my loaves twice. For the first shaping I don't worry too much about how much flour I use, I then let it rest for a couple of minutes to let the gluten relax and then shape again making sure to remove any excess flour (as you would if making puff pastry or croissants). I find that when I do the second shaping that the dough is much less sticky than during the first shaping making it easier to use less flour and as a result of twice shaping find that I get a higher rise and more desirable crumb structure.

If you bake at higher hydrations then a bit of excess flour seems to be less important because the moisture simply permeates through the dough into the dry flour and binds itself back together during the final proving before baking.  

For the shaping itself, do make sure that the skin of the loaf is nice and tight and seal it well on what will become the underside of your loaf. It was explained to me that the skin of your dough is a bit like a leaky balloon and by stretching the gluten you are creating a structure within the dough that traps the carbon dioxide bubbles better, which = better bread in every single way :-)

"it rises really quickly once it hits the stone"

It looks like it's going into the oven too early, the above statement is another symptom of that.

I have also experienced this issue, although fairly infrequently.  In my case, it seems to be associated with under-proofing, as evidenced by very strong oven spring and a much bigger loaf than usual.  I usually bake an 80% hydration dough which is generally a 50/50 mix of white/wholemeal strong bread flour.  I bulk ferment over the afternoon/evening and prove in the fridge overnight.  I suspect that leaving the dough for another hour or two in the fridge, until there are some visible air bubbles under the skin of the dough, would solve the problem.  Strangely, another aspect of my loaves is that the slashes very rarely open up very wide, which I always thought was associated with over-proofing rather than under-proofing.  I would attach some photos of the my latest example, but can't work out how to do so.