In fact – and I digress here – that’s why cookbook authors give time ranges. It’s also why we give visual clues like: bake until a knife inserted in the center of the cake comes out clean; or until the muffin is springy to the touch; or until the cookies are dark brown around the edges and pale golden in the center.
It’s also why I always urge you to get to know your ovens and, most important, to learn to trust your own good judgment.
Back to the oven and the tune-up. Mr. RepairMan said that when the oven light goes off for the first time, the oven is hotter than the temperature it’s set to. For example, he explained that my oven swings plus/minus about 25 degrees F. So, if I set it for 350F, it might go up to 375F and then, when it dips down to 325F, it’ll heat again and go back to about 375F, keeping the average at 350F. But when it first preheats, it’ll go as high as 400F. According to Mr. RepairMan, the oven hits its stride and keeps the most consistent temperature after it has cycled on and off three times.
In practical terms, this means: Be Patient!
When you start to gather your ingredients together and measure them out for your mise en place, that’s the time to turn your oven on.
Writing this, I’m remembering that ‘in the old days,’ recipes used to say things like: “Preheat the oven for 20 minutes.” I haven’t seen that in ages, but I think that if Mr. RepairMan had a say, every recipe would start that way again.