Silicone bake-ware, raw bottoms

[quiviran]

OK, the title says it all. I recently bought a set of silicone bake-ware at BBO. Cake pan, loaf pan and 6 cup muffin pan. I previously bought an eight inch square pan, but don't recall where, probably Target. I'm having the same problem with both sources.

I frequently bake refrigerated cinnamon rolls. I usually use a metal cake pan and they turn out perfectly. My cake pan was starting to have rusty areas, so I thought I'd try silicone, since it would rattle less while traveling. I'm using the convection oven part of a combo microwave/ convection oven. When I use the silicone stuff, the tops are OK, but the bottoms are raw. I have the same situation when I use the square pan to make cornbread. For the rolls, I've tried increasing the cook time at the usual temperature, increasing the temperature at the usual cook time and increasing both the temperature and cook time. I didn't try decreasing the temperature and cook time, figured that was not a path to success. When I increased both the temp and time the bottoms were a little better, with the lines where there was direct contact with the oven rack being almost brown, but the tops were starting to get dried out and overdone.

All of the positive posts I've seen about silicone bake-ware have said no adjustments were required and I've seen all the perfectly baked bread at SubWay using silicone pans, so I figure there must be some technique issue on my part. (I once saw some loaves at SubWay exhibiting similar appearances to my rolls, not quite done on the bottom, although not as extreme as mine. I questioned the teenybopper behind the counter about it. Her reply was "Oh, but they're so soft like this. Not sure if they were not following the recipe, or just got in a hurry that day. Figured there was no point in trying to find out what was happening)

So there you have it. Any ideas on what might be going on? Reflecting on the situation, it seems counterintuitive that material used for pot-holders and trivets would make good bake-ware. What am I missing here?

TIA,
Larry

 

[Andy M.]

The silicone takes longer to heat up than the metal pans so the bottoms aren't exposed to full heat for the entire cooking time. That's why the bottoms are undercooked.

Do you preheat the oven?

Try them in a regular oven.

 

[Fisher's Mom]

Larry, I use silicon pans and I have a convection oven. When baking, I turn off the convection feature and pre-heat the oven and bake the recommended time. I also make sure I use a thick, aluminum baking pan (or cookie sheet) under the silicon pans. Since you're using a microwave/convection oven, I don't know if you have a non-convection baking option. If not, try a baking sheet under the silicon pan and maybe tin foil over the top of the rolls for the first half of the baking time to avoid them being over browned or dried out. Good luck and let us know.

BTW, welcome to DC!

 

[VaporTrail]

If I recall my Heat Transfer classes right, the reason a convection oven cooks faster than your regular oven is that it moves the air in the oven around maintaining the temperature. In a normal oven the air next to your food gives up its heat to the food, and then has to get heat from the air not in contact with the food. If the air next to your food is replaced after it gives up its heat by new hot air, it raises the temperature of the food quicker.

With metal pans this isn't a problem (or I don't think it will be) because of metal's high thermal conductivity (relative to silicone). That is, metal passes off heat quicker. With Silicone's lower conductivity (people in the construction trade might refer to the inverse of conductivity,which is know as R value, and the R value of silicone is higher than that of metal, which makes it a better insulator) the lower half of your food is not reaching temperature quickly enough. The improved (over standard oven) heat transfer through the top of the food shortens the time until the top is cooked, but the bakeware is slowing down the heat transfer to the bottom just enough that the bottom of your food is not fully cooked in the shorter amount of time.

This highly technical discourse gives us what I feel is probably the best advice (and has already been mentioned by Fisher's Mom):

If available, turn off the convection option.

 

[Fisher's Mom]

If I recall my Heat Transfer classes right, the reason a convection oven cooks faster than your regular oven is that it moves the air in the oven around maintaining the temperature. In a normal oven the air next to your food gives up its heat to the food, and then has to get heat from the air not in contact with the food. If the air next to your food is replaced after it gives up its heat by new hot air, it raises the temperature of the food quicker.

With metal pans this isn't a problem (or I don't think it will be) because of metal's high thermal conductivity (relative to silicone). That is, metal passes off heat quicker. With Silicone's lower conductivity (people in the construction trade might refer to the inverse of conductivity,which is know as R value, and the R value of silicone is higher than that of metal, which makes it a better insulator) the lower half of your food is not reaching temperature quickly enough. The improved (over standard oven) heat transfer through the top of the food shortens the time until the top is cooked, but the bakeware is slowing down the heat transfer to the bottom just enough that the bottom of your food is not fully cooked in the shorter amount of time.

This highly technical discourse gives us what I feel is probably the best advice (and has already been mentioned by Fisher's Mom):

If available, turn off the convection option.

Exactly what I said, vaportrail! (OK, exactly what I said only better.) Seriously, thanks for the explanation. Lots of people are getting convection ovens so this is valuable info.

 

[lyndalou]

Has anyone had problems with things breaking apart when you try to remove them from this type of pan? I read somewhere that this is a problem.

 

[Fisher's Mom]

I've had no more problem with this than with traditional baking pans. I always use the baking spray - like Pam but specifically for baking - and then let the cakes cool before getting them out. Occasionally, there will be an edge that breaks off but that's usually because I didn't let them cool long enough, I think.

 

[quiviran]

Hi all,

Thanks for the thoughtful replies. I had to wait a bit to give them a try (don't want to over do the cinnamon rolls).

I have a 1/4 sheet pan from a restaurant supply house that I love, heavy, doesn't warp when heated. I tried putting it in the oven during the preheat period, then putting the silicone cake pan with the rolls on it when the oven was ready. More heat was transferred to the bottom of the rolls and they came out acceptably done. So this does help.

But what's the point. The rolls come out even better cooked directly on the sheet pan. Crispy on the outside, as opposed to brown but soft in the silicone pan. So I think I'll use the silicone pan for keeping batter corralled, like cakes, but bake breads directly on the sheet pan.

Except for cornbread. After reading the cornbread thread, my cast iron frying pan is my new best friend for cornbread.

This is a great set of forums. Looking forward to picking your brains more in the future.

 

[jet]

I have never used them but I thought the point of silicone bakeware was for microwave use.

 

[nathanKent]

(just so everyone knows, Quiviran is my father)

One of the things I didn't think about when we discussed this before was the fact that, at least with the cinnamon rolls, you're not dealing with a true raw batter. I don't know how much that factors into the equation, but it might. You may be dealing with a combination of two or three factors, all working against you, none of which would be an obvious problem by themself.

Also, have you bought a thermometer to gauge the accuracy of the temp control on your oven? RV appliances probably aren't made to the same exacting degree of precision as a $3000+ professional grade gas oven.

We could also run a controlled test in my kitchen with your silicone and my aluminum.

 

[quiviran]

The thermostat on the oven lies like a rug, but I have worked out a time and temperature combination that cooks the rolls perfectly using an aluminum pan. Using the same combination with a silicone pan results in the raw bottoms. Putting the silicone pan onto a preheated aluminum pan improves the situation. The bake time for the rolls is relatively short and I think it just takes too long for the heat to get through the silicone.

 

[nathanKent]

The thermostat on the oven lies like a rug, but I have worked out a time and temperature combination that cooks the rolls perfectly using an aluminum pan. Using the same combination with a silicone pan results in the raw bottoms. Putting the silicone pan onto a preheated aluminum pan improves the situation. The bake time for the rolls is relatively short and I think it just takes too long for the heat to get through the silicone.

How short? Same question also for the cornbread.