Sourdough cracking in the oven

For some reason my last few bakes have been cracking quite badly around the edges on the bottom of the loaves. Anybody any idea what would cause this? 

I havent changed anything, same proving time, same recipe, same amount of dough etc etc


Hi Slowclimb,

I wonder whether your problems are related.  You say that you haven't changed anything but you don't mention temperature.  A few degrees difference in temperature in the kitchen can make quite a difference in what happens with you dough.  That is why you should listen to what the dough tells you about its state rather than sticking strictly to time. Humidity can also be a factor, if the humidity is lower you might get a drier skin that will resist expansion in the oven.   If you have accurate and reproducible temperature and humidity control then you can work by the clock.

Loaves will split in the oven at the weakest point and that is the idea of slashing the top of the loaf.  It gives you control over where the loaf will split and, depending on the slash pattern some control over the shape of the loaf as well.  If the loaf is splitting at the base then obviously this is the weakest point in the skin or the place of highest stress.  The latter results from the high curvature where the loaf changes from flat on the tray or stone to rounded on the surface of the loaf.

I would suggest that you make sure that your loaf is properly proved visually and by using the poke test, taking more or less time as required by the tempertaure in your kitchen.  Keep the loaf in an environment that is non-drying while proving. I use one of those large KlipLok vacuum pack bags. Under a wet cloth or in a sealed area (oven, say) with some water is another way.  If you can turn the oven light on this is one way to get a warmer place as well but it will speed things up more than somewhat.

The other thing is to try baking with steam in the oven for the first ten to fifteen minutes.  I put an ovenproof ceramic pie dish in the oven when I turn it on and then pour boiling water into that when I am ready to start baking.  Just make sure you use oven mitts and take extra care as there is a lot of spitting and steam generated as you do so.  This keeps the crust from setting too early and allows the loaf to rise and reduces the possibility of the side splits that you are getting as well.

Hope this helps and good luck with your projects.


Thanks Farinam,

That all makes sense, I havent been slashing my loaves at all but I think I will now.

I do put water in the bottom of the oven already.

I think I'll look for some of those bags too, I just use carrier bags and shower caps! Its tricky to get the bags to stay on without touching the proved dough sometimes too.

I have been proving at first prove round about 5 hours and second at around 11, what would you use? Obviously I realise there will be temperature variations in the kitchen but roughly?

Hi Slowclimb,

I would only be looking at those sort of times if it was very cold.  Even if I retard in the fridge, it would probably only be overnight.

I use the stretch and fold technique for dough development and that might run to three to four hours but I go on how the dough stretches and springs back rather than any particular timing.  If I prove the loaf in a warm place such as oven with the light on/ dough proving setting maybe three hours before taking it out to heat the oven for baking.  Room temperature proving maybe four hours to six hours depending on temperature (have left it out overnight in the depths of winter) but as I say, I go more by look and feel that sticking to a particular time frame.

How does the dough behave when you transfer it to the oven and what sort of oven spring have you been getting?  Possibly you have been over-proving plus drying of the skin if not well sealed or kept humid.  What do you use for proving?  If you don't have bannetons, I have found that a colander lined with a (rye) floured tea towel serves well for boules and a cheap oblong cane basket similarly lined for batarde.  if the sides are high enough you shouldn't have any problems with touching the dough.

Good luck with your projects.


Hi there,

Yep I do have bannetons. 

I do get a fair bit of spring when baking.

I was told longer cooler proves would give better flavour, do you find this?

Hi Slowclimb,

The theory is that time allows the bacteria to work on the waste products from the yeasts ( and other stuff) to produce acids that give a more sour taste.  You also have to keep in mind that at lower temperature, everything slows down though not necessarily at the same rate and one theory is that this is the value of retarding, in that the bacterial action does not slow as much as the yeast action and so you end up with a higher acid concentration relative to the rise that you have obtained from the yeast - though some of the bacteria also produce carbon dioxide and contribute to the rise.  Time is also the enemy of the gluten structure of the dough and if this breaks down you end up with a loaf that collapses and gives little oven spring (over-proving).  Also if too much time is given, all of the sugars are consumed and the loaf does not brown well in baking. 

I think that many people have an expectation that bread made with a sourdough leaven has to taste sour.  The term sour applies to the culture used to leaven the dough, not necessarily to the finished product.  I have found that the bread can actually have sweet overtones (or undertones if you like) when the bread is fresh but that a sourness develops as the loaf ages.  Theoretically any living components of the dough are no longer living due to the baking but possibly acids present are concentrated as the bread dries out with age thus intensifying the taste.  A number of commercial 'sourdough' breads can give a false impression of what the taste should be due to the fact that souring agents are added to something that might not necessarily be made from a sourdough culture. Cavaet emptor.

Good luck with your projects.