In our kitchen we have a great electric oven, it preheats pretty fast (a matter of minutes!), has loads of space and seems to be pretty reliable regarding temperature. It’s perfect for making pies and bread. One of the great things of baking bread is that people have been making bread for centuries, if not longer, in all sorts of ways and shapes. When putting my bread in the oven one day though, it got me wondering. How did they bake bread before we had our fancy ovens, with easily adjustable temperature, easy racks, etc.? There’s no easy way to determine the exact temperature of a fire…
This is what I set to figure out and it brought me back in time, exploring oven history.
First of all, we have to go back in time. Back to the time before gas or electric ovens existed and before everyone had their oven oven. At the time, there would be communal ovens for everyone to use, sometimes in exchanged of some sort of payment. Or, there would be bakers to whom you could bring your bread to be baked. Richer households might have their own ovesn, while poorer families would more commonly go to a shared oven. How this worked depended on the region and country but proof has been found that thousands of years ago people already used ovens.
At the time, ovens were often big brick/mud constructions. The constructions were pretty good in keeping heat inside and were well insulated. Sharing the oven reduced the required fuel of course.
These large well-insulated oven were heated with wood, and later coal. Temperatures could go up well above 400°C during burning. Flat breads can be made in these ovens relatively quickly. The thinly rolled out dough is held against the hot wall and it cooks within a few minutes. Larger breads and things like pies and pastries however require some more temperature control skills.
Controlling oven temperature
Controlling the temperature of these wood fired ovens is pretty complicated. The wood can make the ovens very hot, but over time the amount of burning wood will change, causing the temperature to change. Furthermore, the oven would actually get too hot for bread to be baked inside. So, smart tricks had to be devised.
Since in colder regions in Europe especially the oven was not only used for baking, but also heating of houses, they developed quite some techniques to control the oven. Products weren’t necessarily baked inside the oven while the fire was burning. Instead they would scrape away the ashes and wait for the oven to cool down slightly before baking something like a bread.
People didn’t have thermometers at the time of course, so they used other ways to determine whether the temperature was good for baking. One method was to throw in some flour. If the flour browned at the correct speed, it would be ready. It’s a trick still being used!
Enter: gas and electric ovens
Before the 19th century most people still cooked over open fires and ovens would be heated by fires as well. Around the end of the 18th century new, more compact stoves were designed, using either coals or wood for heating (here’s a beautiful example). These new designs wouldn’t require the large fireplaces anymore and were more efficient in heating. At the time, ovens and stoves were one and the same thing and you wouldn’t see one without the other.
Then, in the 1820’s the gas oven was invented and patented (unfortuntaely, I haven’t been able to find the patent itself). The use of gas made them a lot easier to control and use. They wouldn’t have to be refilled with wood or coals, nor would the leftover burnt product have to be removed.
These first gas ovens weren’t very popular yet, that took a while, partly due to availability of gas. Not in every country this went with the same speed. Great Britain was one of the first to have gas widely available.
By the end of the 19th century electric ovens came on the market as well. Again, the speed of the introduction depended on the speed of the introduction of electricity to households.
Temperature control was still an issue
By searching through some patents I managed to get a better idea of how these ovens were used at the time. It seems (patent US2510526A) as if ovens were first heated to high temperatures (as was the case for the older brick ovens). The product to be baked/cooked was then placed in the oven and oftentimes, no further heating would take place anymore. So the product would be cooked on residual heat, while the oven cooled down slowly.
This is probably partly due to the poor temperature control of these ovens. They couldn’t be controlled for temperature very well yet. They might have marks such as low, medium and high, but nowhere close to an exact temperature configuration.
It seems as if somewhat later in time some sort of temperature control was possible. I found an invention in which it was mentioned that gas ovens would have either a large burner or a small burner. The large burner would allow the oven to heat up quickly, however, it wouldn’t be good at maintaining lower temperatures. The small burner might maintain lower temperatures, but wouldn’t be able to heat up quickly.
Thermostat – a small revolution in oven history
The trouble with temperature control would end with the introduction of thermostats for ovens, somewhere in the beginning of the 20th century (one of the years mentioned is 1915). Thermostats can be used to control temperature, for instance in an oven. They are often made of metals which will expand upon an increase in temperature. The amount of expansion could be used to regulate temperature. This marked an important moment in oven history!
Some described this introduction in the oven as being some sort of a revolution for housewives at the time. The temperature control would make it a lot easier for them to cook and do something else at the same time. In the decades to come the thermostat would go through some significant improvements, as found in various patens.
Only with the introduction of thermostats did temperature settings or gas marks enter the oven market. Even though the thermostat allowed for temperature control, it wasn’t too accurate, especially in the beginning. Nevertheless, it greatly changed cooking and also allowed less experienced cooks to use an oven.
Oven history & esthetics
Simultaneously, not only technical developments took place, but also esthetical ones. The design of kitchens changed quite significantly over time. The depression (which also had a great influence on popcorn sales if you’re interested) and the first and second world war greatly influenced the way people thought and bought. I’m not an expert on this, but read here if you’re interested in learning more.
Temperature accuracy of current ovens
Over time, both design and technical functionalities of ovens have kept developing. Nevertheless, even the current ovens aren’t exactly accurate when it comes to temperature. Keep in mind that +/- 10-20°C isn’t very uncommon for a household oven.
Keep this in mind when baking, but do think about those bakers centuries ago, who had far less advanced methods to control their baking and cooking processes!
Want to learn more about wood fired ovens?: William Rubel.
A history of cooks and cooking, Michael Symons, 2004, p.74