I assumed that the temp had to remain constant during the steeping. I wasn't confident in my ability to keep a constant temp on the stove, so I thought I would use the oven. Do you use a heavy enough pot that you don't get a significant temperature drop, or is it just not that big of a deal?
I was curious about you using the oven too but I see what you're saying. And yes, you want to keep the temp steady unless you are doing a stepped steep.
No, I do not use real heavy pots. Actually, my current favorite is an aluminum one.
When I use my turkey burner, I leave the pot on the burner to steep, TURN OFF THE BURNER, and wrap it in a heavy blanket. On a calm day I usually don't have more than a degree or two of drop if any at all. On the blustery days, when the temp starts to drop, I unwrap the blanket, crank on the burner for a couple minutes until up to temp, shut off burner and re-wrap blanket.
When i used the stove, I would leave the pot on the stove and just turn the burner back on if it started to cool off too much. You might be surprised at how much heat it will hold for how long. But if you have an electric stove, you have to be ahead of the power curve because it takes a bit for the burner to heat up enough to actually transfer heat to the pot. With the turkey burner, I could let temp drop two degrees and have it back up in just a minute or two. On the electric stove, that same two degree drop might take 15 or 20 minutes to overcome.
At one time, I had a very crappy electric stove and it took 3 hours on high to bring a 15quart partial mash to boil. Came out great but very dark (caramelized) from the extended heat. That one, I had to leave the burner on the entire steep but did reduce it to medium/medium low.