People blame their starter. Usually it is the oven.
A home oven cannot do the one thing a bakery oven does: flood the chamber with steam for the first ten minutes of the bake. Without it you get a loaf that is perfectly edible and slightly disappointing — pale, soft-crusted, and smaller than it should be.
What steam is doing
Three things, all in the first ten minutes.
It delays the crust. A wet surface cannot brown. While the outside stays damp, it stays flexible, and the loaf can keep expanding. That expansion is oven spring, and it is where most of your volume comes from.
It gelatinises the starch on the surface. That thin gelatinised layer is what later becomes glossy, blistered and genuinely crisp — rather than merely dry.
It transfers heat faster. Steam moves energy into the dough more efficiently than dry air, so the inside sets while the outside is still soft.
Once the loaf has stopped rising, you want the steam gone so browning can begin. Hence: lid on, lid off.
Why the cloche works
A lidded cast iron vessel does not need you to add water. The dough is roughly 40% water by weight, and in a sealed space that water becomes the steam. The loaf makes its own weather.
Cast iron matters here for a second reason: thermal mass. A preheated cast iron base dumps heat into the bottom of the loaf the instant it lands, which drives the initial rise. A thin baking tray loses its heat to the cold dough almost immediately.
The method
Preheat the cloche with the oven, lid on, at 230–250°C for at least 30 minutes. Putting a cold vessel into a hot oven risks thermal shock and wastes the thermal mass entirely.
Turn the loaf out onto parchment, score it decisively — one confident cut, about 1cm deep, at a shallow angle — and lower it in using the paper as a sling.
Lid on, 20 minutes. Do not peek. Every look costs steam and temperature.
Lid off, 20–25 minutes. Drop the oven to around 220°C. This is where colour happens. Take it further than feels comfortable — a pale loaf is an underbaked loaf, and most home bakers pull too early.
Cool on a rack for at least an hour. The crumb is still setting. Cutting hot gives you a gummy interior and no amount of technique will fix that.
Shape follows vessel
An oval cloche suits a batard — the long, tapered loaf that slices into sandwich-sized pieces. A rectangular one suits a tin loaf shape, which is the one that actually fits a toaster.
Neither is better. Choose by what you eat.
Enamelled or bare
Enamelled cast iron needs no seasoning, will not rust, and releases a loaf cleanly. It is the low-maintenance option and the right default.
Bare cast iron builds a seasoning layer over time and some bakers prefer the way it colours a base. It also demands drying and oiling after every wash.
For bread specifically, enamelled is easier and the results are indistinguishable.
If it is still not working
Check the temperature with an oven thermometer rather than trusting the dial — domestic ovens routinely run 20°C cool. Check that your scoring is deep enough; a shy cut closes up and the loaf bursts at a seam instead.
And give the dough a cold overnight proof in the fridge. It is easier to score, easier to handle, and the flavour is better.
None of this is about a better starter. It is about heat, steam and nerve.