Home oven mysteries

Hi David,

Your post implies you are using a pre-heated stone in the oven.   From your previous posts, this is also my recollection.

The conducted heat is doing the principal "baking" job.   The temperature above your loaf, which you have been measuring, will be of the heat primarily involved in colouring your finished bread, through some radiation and some convection.

My advice is to take a look at the time your bread is in the oven, and the degree of crust formation you seek...this being very much an individual preference.

If you are happy with the bake profiles you have been achieving, then why change?   If you want to bake your loaves in a shorter amount of time [and this is physically possible], then you may need to raise the temperature of the convected and radiated heat within your oven chamber.

Hope this makes sense to you

Best wishes

Andy

Hi David,

I don't know what oven you bake in, but I have seen pictures of the large brick beast which Jeffrey Hamelman uses at King Arthur.

When that gets hot, it stays hot for hours.   So, there is less need for the thermostat to kick in and give a serious blast of fresh heat.   Everything just ticks along nicely with a gentle supply of heat to keep the oven at a regulated temperature.

In a home oven, open up the door, and load in your loaf, and the oven has just lost an inordinate amount of heat.   So, the thermostat kicks in and supplies as much fresh heat as possible to compensate.   This is the heat which burns your bread.   That is why I was pointing to the heat stored in your baking stone as being the most significant.

Jeffrey Hamelman is quite right to call for baking at specified temperatures.   But you cannot get away with simplifying that down to a number on the oven dial.   There is much more to baking than that.   Additionally, his target audience is, in the main, professional bakers.   So his reference point is a commercial oven, not a home oven.   They are completely different animals, believe me.

Best wishes

Andy

Hi David,

I use a regular electric oven at home; it has a fan.

I have put 3 bricks inside it to introduce masonry for heat retention.

You probably know I use deck ovens in College.   You can see them in action here: http://www.thefreshloaf.com/node/21867/boules-made-gilchesters-flours-and-different-preferments

They do use 3-phase electric, which will be your biggest drawback.   But they stack on top of each other, so there is nothing to stop you just having a single deck with steam fitted.   The 3 decks cost me just over £13000.   But if you don't have 3-phase, I'm not sure it's really worth buying a commercial oven.   You'd have to deal with one of two issues: either lack of safety because the oven was too powerful for your electric circuitry, or, an oven which was not as powerful as it pretended to be, and, therefore a letdown.

By the way, have you ever taken a look at the wiring inside the oven which deals with all the power?   Mine has the skinniest little wires imagineable.   Sorry I can't be more helpful....how about building a wood-fired oven?   Mine sits out on the back patio, but I rarely seem to get a chance to use it!

Best wishes

Andy

David, when you test your oven for temperature accuracy and stability the oven needs to be empty  -  nothing but the thermometer and the racks.

It appears to me that, if your oven cycles with a temperature spread of twenty degrees (380 - 400) you've got a pretty good oven.  Once you've got a handle on the accuracy of your oven temperature control knob markings relative to the actual oven temperature you can adjust the control knob (or digital readout if that's the style you have) to the correct setting.  Be sure that any adjustments you make reflect the highest temperature in your tests.

If your bread is coming out just fine, don't change it. The heck with "theory" (unless you eat "theory":-).

That said, there are a few things you might like to know about ovens (especially home ovens).

1. The way ovens work is they cycle back and forth between slightly below the desired temperature and slightly above it. This is  completely normal. It's not unusual to see an oven cycle between 25F below the desired temp and 25F above it. So, to get a completely accurate picture of how hot your oven is, you'll need to look at the thermometer several times, write down what it says each time, then use the  middle of those numbers. Looking at the thermometer just once is likely to catch the oven either at the end of its down cycle or at the end of its up cycle and so be rather misleading.
2. Ovens can cool down substantially, and can take a long time to "recover", when the door is opened. Just putting the dough in may drop the temperature 50F, and the oven may take 15 minutes to get back up to temperature.
3. The ready temp sensors in ovens do not account for baking stones. However long it takes for your oven to say it's up to the desired temperature, allow at least double that amount of time for "preheating".
4. The temperature in a home oven is very commonly off a little from what the knob says. Differences of 50F are not uncommon. (That's why "oven thermometers" are so common.) In fact, most home oven controls have some sort of "adjustment" (a screw on the back of the knob, or down the center of a hollow shaft, or ...) so you can correct the knob to match what's really going on in the oven. Although you don't really need to do this, you may find it more convenient, and you can feel fully justified in doing so as it's very common.
5. The metal case of an oven thermometer can conduct enough heat to throw off its reading. If possible, hang the oven thermometer (the case probably has a "hook shape" near the top) from an empty rack near the top. Try to place the oven thermometer to one side or the other away from the top element, as that element will come on during preheating and could throw the oven thermometer way off.