The Pursuit of a Crunching Crust, and ponderings thereof

Mak­ing bread at home is a supremely incon­veni­ent pas­time. It takes hours, makes the kind of mess I haven’t man­aged for years and pro­duces – too often – a dis­ap­point­ing res­ults. In my new bread bible, Eng­lish Bread and Yeast Cook­ery, Eliza­beth David calls home-baked bread crusts ‘leath­ery’. We want thick, hard, crunchy crusts.

She’s got a point. To under­stand why, we need to return to first prin­ciples. Why does bread get a crust? The crust is the inter­face between the hot oven and the fairly cool bread/dough. It’s a thin layer of dough that gets cooked to high hell by – in a real bread oven – some­thing like 500 Roman Cath­olic degrees of heat. Think of it like a potato. If you boil them, so that the out­side is exposed to noth­ing higher than 100°C, the res­ult is soft and pale. Shove them into a deep fryer and some­thing closer to 190°C and you get a crust. It’ll col­our, it’ll crunch and, hey presto, it’s a chip.

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This simply doesn’t hap­pen in domestic ovens because they’re too darn luke­warm. My oven won’t go higher than 250°C (accord­ing to its ther­mo­stat), which – by way if con­text – is a bit like try­ing to cook an egg in hot bathwa­ter. It’ll even­tu­ally hap­pen, just not quite like you’re used to.

I built a wood-fired and brick-built bread oven last sum­mer, and have used it almost exclus­ively for burn­ing things. It uncanny. Put a pizza in the elec­tric oven at full whack and it’ll still be soggy after ten minutes. In the brick oven, it’s burned to a cinder after two.

The weird thing is that these thing actu­ally cook, prop­erly and all the way through, in this extreme heat. Part of the reason is that the heat is radi­ated – that’s to say it flies invis­ibly through the air like the sun’s rays or the heat from a grill/broiler – rather than simply being mashed about by a breeze of very warm air. This heat comes from all dir­ec­tions, not just the base, not just the fire, but the whole great domed roof.

Best of all, it makes steam. Steam, slightly counter-intuitively, is the vital factor in mak­ing a decent crust. Steam gives the baguette (inven­ted in 1920) its delect­ably glazed, crackly crust. That steam is totally arti­fi­cial though. In some­thing called the Vienna pro­cess, a heap of super­heated water is dashed into the very long indus­trial ovens they use. Wood fired ovens are so quick they don’t even need that. The mois­ture from the loaf itself provides a quick, loc­al­ised steamy ball that looks after crust development.

Get­ting good crusts at home should demand two things: lots of heat and lots of steam. This is harder than it sounds. Firstly, turn­ing the oven to the abso­lute most com­pletely highest tem­per­at­ure set­ting its got is a must. That’s nowhere near high enough, but its the best we can do.

Next comes steam. The pre­vail­ing wis­dom for a long time now has been to put a dish of hot water at the bot­tom of the oven. This works to a cer­tain extent, and can cer­tainly help crust devel­op­ment, but is often a hindrance. Firstly, the chosen dish needs to be pretty heavy and extremely hot. The water needs to be a recently boiled a pos­sible. Put­ting cold things into a hot oven will not make it any hotter,

The other sug­ges­tion is to fill a plant sprayed with water and give your oven a good squirt before clos­ing the loaf in to do its busi­ness. Bright sparks like Richard Bertinet prefer this way of doing things, but again I can’t help but think that – though that might be bril­liant in a supremely hot bakers’ oven – some­thing more ingeni­ous is needed to over­come out tem­per­at­ure issues.

Whatever method you choose, let­ting the steam out is the oft for­got­ten but pretty damned import­ant bit. Crust form­a­tion has a lot to do with evap­or­a­tion of mois­ture from the out­side of the dough. Put­ting steam in the oven pre­vents that from hap­pen­ing, so – to get proper crust – let­ting the steam­ing bread dry out for a bit is just about essen­tial. The folks at the Week­end Bakery make a big point of let­ting out the steam five minutes before finishing.

Eliza­beth David has a very dif­fer­ent, very effect­ive and very well informed method of her own. She recom­mends cov­er­ing the loaf with a large, ceramic bowl. The exact type of unglazed ter­ra­cotta she recom­mends (and she is very spe­cific) seems a little like overkill to me, but the premise of mak­ing a fake oven within and oven is very valid an idea indeed. This is how the first ovens worked. People put upside-down pots over loaves on hot stones, then stacked hot embers around them. In Corn­wall, ‘bakers’ and ‘kettles’ as they were known, were in com­mon use as recently as the 1930s.

My inter­pret­a­tion of her method is to put the bread into a thor­oughly pre-heated cast iron cas­ser­ole – some­thing that David doesn’t recom­mend. Unfor­tu­nately, this bears a dis­tinct sim­il­ar­ity to Jim Lahey’s ultra-hyped no-knead bread (I rather knead than spend a whole day proof­ing, but that’s just me). Nev­er­the­less, it seems to work won­ders – espe­cially with very high hydra­tion doughs that are apt to spread and tumble.

Drop the proofed loaf into the hot cas­ser­ole, slash, cover and cook for about half an hour. Take off the lid for the last fif­teen minutes and, whatever you do, don’t for­get to have greased, floured and semolina’d your pot.