What specifically has happened as the result of this? Are you saying the flame comes on for five minutes at a time to maintain the heat after it is fully preheated? Some people have reported temperature swings as little as 10°F on either side of the set temp, but even if it was 25°F which is the standard variation, 5 minutes would be a long time to move the oven back up 50°F to the other side of the set temperature by 25°F. How long does it take to preheat initially?

Thanks for your comment. Yes, that is exactly what's happening. It takes a solid 20 minutes to preheat initially. The big issue is specific tasks that leave the oven door open for longer than usual. Inserting a pizza, for example: it might stick to the paddle, go out of shape on the way into the oven, and need a little reassembly on the stone. The oven will lose a great deal of heat, and it then takes a while to get back to temp. That's basically the entire cooking time for a pizza, and without convection, it just won't turn out the same.

Even in other tasks, I'd just greatly prefer if the convection fan were running the entire time (after the initial preheat, of course). It just seems like a better method for preserving even heat across cooking.

When you open the oven, most of the heat that is lost is because of cold air replacing hot air. But air doesn't have a lot of heat capacity. Most of the heat energy is stored in the walls and other mass. If you want to improve reheat time (at the cost of even longer preheat times), add more mass. I recommend something like a fibrament baking stone.

That also explains the really long preheat times for bigger oven cavities. It might take only a relatively short amount of time to heat up the air. But by that time the oven isn't completely preheated yet. The walls still need to fully heat up in order to get a stable oven temperature.

So, if in doubt, preheat longer. I have seen recipes for bread and pizza that recommend 1h of preheating. And these were generic recipes, not anything specific to a particular brand. This probably also explains why pan pizza works so well.

On the other hand, there are plenty of dishes that don't really benefit from preheat. Most cakes are pretty tolerant of different baking temperatures, and roasts as a rule can handle temperature fluctuations as well. So, for those items, I frequently don't even bother with preheating.

When you are baking pizza, what temperature are you aiming for? Are you using the maximum that the oven provides?

I agree with longer preheats to make sure the entire oven is preheated and this provides radiant heat from the walls of the oven.

I bake quite a bit and never use convection for cakes or anything that needs to rise, at least during the first half of baking. It’s not to say that you can’t with some recipes, because some do, but most cake recipes were developed in regular ovens with heat coming from the bottom. One exception to this is recipes from Rose Levy Beranbaum (The Cake Bible). I think she advocates using convection with her recipes. “Even heat” coming from all sides changes the way cakes rise. It is also drying to the surface of the cake so inhibits starch gelatinization, reducing rise. You already have more airflow through a gas oven, which is more drying to the surface of what you are baking. I do think cakes and really any baking I do requires a long preheat because I want the oven stabilized and the radiant heat from the sides. I usually preheat at least 30 minutes in my smaller wall oven. If you are worried about heat loss when opening the door, preheat the oven to 25°-50° higher than what you need. You might have to experiment to see what the optimum increase would be. Turn it back down after you put whatever you are baking back into the oven. I often use convection for cookies but have also baked many years without it. If you are not finding it necessary to change trays around, it wouldn’t be as much of an issue, preheat a little bit over and load your cookies and turn it down. You would turn it back up between batches. If you do need to change cookies around midway through baking, the convection isn’t as effective in “evening” the heat so you could do without it. In roasting, I almost never use convection the whole time of cooking anyway. Aside from the pizza which may require the door being open longer, most of these other things probably don’t require the heat to come on for 5 min but cookies with a short baking time might still be affected by this.

Thanks for your reply. Not sure what kind of range you're using, but with our Bluestar, we've found that it works best to use convection whenever baking or roasting. What's so frustrating about this is that the convection fan is not running for up to 25% of the time we're baking things due to the natural cycling of the oven's temperature, so things just aren't turning out right.

What do you mean when you say "things just aren't turning out right"? Can you give examples?

I have a 2010 Bluestar RNB (so, not subject to the recall). It bakes amazingly evenly both with and without the convection fan. I don't actually use the fan all that often. The only time I do turn it on is when I need really fast heat transfer and high heat. That's mostly limited to things like baking bread. And adding moisture is actually more effective in that particular situation.

I find, my Bluestar oven is mostly really boring. And that's a good thing. I turn it on, I preheat (at least 20min, better longer), and it bakes or roasts reliably and evenly. Nothing more to say.

I do have a baking stone in the oven most of the time, as the stone is so big I don't know where to store it otherwise. But I find even without the baking stone, the oven works great. What exactly is the problem that you are observing?

Thanks for your message. This is a 2015 model. We've found that without convection things don't bake evenly. For example, a pizza will cook on the bottom thanks to the stone, but the top will be pale. We ran into this problem with biscotti on the first day of the recall fix as well: for the second stage (after you slice them and need to do the second bake), they simply failed to finish on the top before they started to burn on the bottom on the tray. It's super frustrating, because we absolutely loved it before and feel like this fix has made it not only unpredictable, but borderline unusable.

“What's so frustrating about this is that the convection fan is not running for up to 25% of the time we're baking things due to the natural cycling”

M, does that seem right, that the burner is on 25% of the time? Maybe something else is wrong.

If you have more browning on the bottom for something like Biscotti, what type of cookie sheet are you using? Because your oven has changed, you may have to change what you are doing. If you preheat the oven as M and I suggested and even heat it above what you want, by the time you open the door and lose a little heat, it is still at the high side of the temperature swing and it will delay the burner from coming on at the beginning. It might be enough on things that only cook for a short time to keep the burner from coming on. I used to not want the burner to come on on an oven I had for a different reason but it worked pretty well to do that. You may have to change the type of cookie sheet you are using or stack two to insulate the bottom.

With the pizza, you might have to use your broiler for a bit.

Whatever the percentage of time the fan is off/burner is on illustrated by that chart, it seems like a lot. I would call BlueStar and see what they have to say. What do they suggest? They have fundamentally changed the way the oven works.

You might still be able to make it work a little bit better by the changes above and also you might try placing things a little bit higher in the oven. I also wonder if placing a baking steel up as high as you can might provide some additional radiant heat from the top, especially if you try overshooting the preheat a little.

You really should not have to be doing all of that.

Thanks--that's EXACTLY how we feel. They have indeed fundamentally changed the way the oven works. We loved it before, and now we're super frustrated. We've called BlueStar and have had quite unsatisfactory results. Evidently the service manager is on the road at the moment, so the person we've spoken to has been quite unhelpful.

Thanks for this graph, John!