How to use an oven properly
Baking bread is trickier than the recipe books will tell you! But it's also simpler.With a bit of thermal understanding, you can turn a well made and formed dough into something special via expert use of the oven.
That's why you need to read this to understand how to get the results you want.
A BIT OF BACKGROUND
I have to be fair to the humble domestic oven - it has to be all things to all people. It has to roast lamb, bake vegetables, pies, lasagna, and reheat last night's dinner, as well as bake cakes and bread. That's a big call for any oven, and if you were to visit the pie manufacturer, the cake company and the caterer, you would soon learn that they all have very different ovens for their respective tasks.
Quite a bit of the difference comes down to moisture. Some things should be baked in a dry oven, while others, especially certain types of bread, need a lot of moisture. Then there's the question of what kind of moisture do you need? Is it warm or cold? Is it a fine mist or a thick spray?
The question of heat is also crucial. Some ovens deliver sharp, quick heat, while others deliver more stable, even heat. I've opened the door on many domestic ovens to put the bread in, and instantly lost half the heat. Then it has taken me some time to get the temperature back. Does wonders for the 'kick', I can tell you!
On the other side of the coin, I have needed to drop the temperature of the oven quickly, so as to maximise the rise without crusting the bread, and found that the oven wasn't budging from it's temperature.
If you've worked in a bakery, you'll know that bakers are spoilt for control. Most bakery ovens are sensational when it comes to crust and colour and control. And then there are specialist ovens - old time bakers just go all misty eyed when they see them (traveller ovens, and certain types of wood fired ovens such as Scotch ovens come to mind). I've often been tempted to reopen a failed bakery on a poor site just because of the oven left behind!
BREAD BASICS
Different recipes call for different things. If you are an advanced baker, you'll have tried a recipe many times, and will be looking for certain variations in the finished product. For example, a common wish is for a thicker crust without burning, or a thinner, crispier crust. These variations can be achieved in a domestic oven, with a bit of tweaking. It's not always possible to get exactly the desired result, but a bit of practice with some understanding of the general principles will get you to where you want to go.
It comes down to knowing what you want to make. I've broken it down into categories of bread styles and uses for the breads you are making. They are as follows:
Soft, light crust. Suitable for sandwiches or other uses where you don't want to be chewing hard. For example, social occasions where the bread might be eaten in the company of others, and conversation is key. Thus, crunching is out!
Thin but Crisp crust. Suitable for picnic breads, finger foods or times when appearance is important, but where the bread has to hold its shape.
Thick and chewy crust. Good for times when the bread has to make a strong statement, and where appearance and colour can afford to be robust. This type of bread suits mediterranean and italian feasts, for example, or when it is used for dipping into soup or other liquids and needs to hold together.
There are a few other details too - the size of the bread will come into it, whether it's tall or flat, and the total volume of the bread being baked; one loaf or two, for example. The oven itself will make a big difference - gas and electric are quite different types of heat (see 'domestic ovens'); convection or still air; and the capacity of the oven - how much space there is around the outside of the bread when it's placed in the middle.
A fair bit of this is either common sense, and / or trial and error, but people frequently experience problems with these things, so this section is intended as a bit of a guide to save a few dodgy loaves from ever happening. There is nothing more frustrating than lovingly tending a sourdough for a whole day, only to ruin it in the oven. And when you get a bit more advanced, the fine detail will really lift the finish of your bread.
Note: I don't want to repeat stuff that's in the linked section on domestic ovens, so follow the link above first.
CRUST
Controlling the crust is mostly to do with moisture, and also time in the oven. It actually has very little to do with temperature.
To set the crust correctly, you generally need steam in the first half of the baking cycle.
As a default position with most domestic ovens, I place a small bowl of water on the floor of the oven before I turn the oven on. Then I allow an extra ten or fifteen minutes after the oven has reached the desired temperature, so the water begins to evaporate. This will make the air in the oven moist, at the very least.
I work with 180 degrees celsius as my default ambient temperature; but I like to get about 220 C on the baking surface, if I'm baking directly on the sole. Baking temperatures can be modified for numerous reasons:
the volume of the bread in the oven compared to the overall capacity of the oven. If the oven is pretty full, because it will be closer to the elements, you may find that a slightly lower temperature works better for you. If you are getting uneven crust, this could well be the reason - just lop off ten degrees at a time and see how it goes. However, add about ten minutes to the total baking time as well.
If you have a large oven with only a small loaf in it, the opposite applies, because it's a long way from the heat. Remember to shorten the baking time a little, though.
Convection ovens are hotter than those with still air. See the atricle on Domestic Ovens.
Crust considerations - see below for some techniques to achieve different types of crust.
For a soft, light crust, use the bowl of water as your means of getting steam going in the oven. You actually want a higher temperature in the oven and a shorter baking time. About ten degrees hotter will do the trick, coupled with about ten minutes less in the oven.
If you want a thin, crisp crust, heat the oven to approximately 30 degrees celsius above the desired temperature, and let it sit there for at least fifteen minutes, so as to stabilise and get the walls hot. Then, just before you load the oven, spray the side walls with a mist spray gun. This will cause there to be a fair bit of steam in the oven. Quickly load with bread, and close the door. Reduce immediately to the desired temperature, and bake as normal.
If you do these two things together, you will achieve a good, thin crust, and golden colour.
If you are after a thicker crust, you will want a drier oven, in a general sense. You may choose to only spray the walls at the beginning, and leave the bowl of water out. You may alternatively use the bowl for the first half of the bake and pull it out halfway through. In general, though, after about ten minutes in the oven, wipe a good 20 degrees off the temperature (or more), and bake for an extra 20 minutes to half an hour longer. At low temperatures, you are not likely to burn the bread, so just keep baking until the crust is how you want it. Italian bakers often bake at as low as 120 degrees for an hour and a half to get a really thick crust. I've even wound the oven up to temperature, put in a load of bread, and turned it off. I've then taken the bread out the next day and had a sensational crust as a result!
KNOCKING THE BREAD
A sharp knock on the crust will deliver a hollow sound if the bread is cooked. If not, it will sound more like a dull thud.
It might sound strange, but you will also be able to smell if the bread is cooked when you have trained your nose. This comes from experience, and is very reliable. I can smell hot dough, versus crust. Most bakers who have worked in bakeries for years have this skill too, even though they might not actually be able to articulate exactly what they do.
CONCLUSION
Good oven technique is largely about experience, which does mean trial and error. However, if you work from these guidelines, even though they may seem a bit counter intuitive at first, you will find that you will quickly master your oven. The temperatures I have stated will vary quite a bit. Above all, be consistent in your approach - if you are going to change things, change one thing at a time, otherwise you won't know which change worked!
If you want to learn all about ovens and sourdough in a hands on, full day workshop, check out our School of Sourdough workshop series. They are held in the lower Hunter Valley each month.