firing in cold/snow?

[KEmerson]

I was reading on The Fresh Loaf web site about someone who built an earthen oven that developed cracks after firing in very cold Canadian weather. I am fairly certain that could just be one of the issues with earthen ovens but I am wondering if it applies to our Pompeiis. I feel sure that it won't be an issue but as this would be my first winter I sure don't want to have any trouble. My supposition is that since the Pompeii is so very well insulated there should be no concern. We just got seven inches this morning (still falling as I type) and though I have no plans for baking in the next few days, it would be good to know. We had a bit of a dusting earlier in the week, the season's first snowfall here. A little snow stayed around and I had a small cap of the white stuff on my oven top. I was baking a dozen sourdough loaves when my friend looked up and noted that even with temps having reached over 900? F. the snow stayed. My IR thermometer showed that the exterior of the oven was cold all over. That bugger is very well insulated (and as the mantra here states, you cannot over insulate. Too true.)
So I'm just wondering if there is anything I should know about firing in the winter. A slower heat build up? I am fairly certain there's nothing to worry about but I thought I'd ask anyway.
And that sourdough was drop dead beautiful, by the way. How does one keep from devouring a whole loaf at one sitting?
Thanks
Kim

[Jed]

Re: firing in cold/snow?

Hi Kim,

In my opinion, the larger concern about firing an oven in cold weather is more about moisture in the brick than the temp of the oven when you start...

If there is any moisture in the brick, the heat from a fire will change the wet to steam, and the expanding steam will potentially crack your oven from the expansion of the water. I don't think the brick will change shape just because you started the fire on a cold day... if the brick is dry...

Just an opinion!

JED

[KEmerson]

Re: firing in cold/snow?

Jed,
That makes sense. I imagine you mean the interior of oven. So as long as the brick is dry it should all be ok. I can't see how the brick would be wet if the door is in place. But I will definitely check for wet/dry brick before firing up next. This would probably be true even in warmer weather after a rain, right?
Thanks
Kim

[RTflorida]

Re: firing in cold/snow?

I will second JED's thoughts. Moisture is evil, whether it be from the forces of steam or from water turning to ice and causing damage. The effects of a 50 degree, or even a 100 degree temperature swing are neglible. Unless you are talking about extreme cold firing (Arctic Circle), I don't think you have any worries. 10 degrees, or even zero may seem very cold to our skin...but remember a firebrick is design for cold-hot-cold cycling. We ramp these ovens up from ambient temp to over 1000 degrees in under an hour, another few degrees won't hurt.
That being said, I'm in FL.......the coldest I have ever fired my oven was when the temp was around 32-34 degrees, certainly not cold by your definition.

RT

[KEmerson]

Re: firing in cold/snow?

But we're still talking about the inside, right? So if it's dry inside it makes no difference what the outside is? Because a well insulated oven shouldn't even warm up at all outside due to any fire inside. And cold is one thing, but wet is another. So a dry but very cold oven is not a problem whereas a wet but warm one is. Do I have that right?

[RTflorida]

Re: firing in cold/snow?

I would say you have it. I know snow country is just as bad as my humid and vertical rain. I have had my share of problems from rain getting into the dome and insulation, I certainly would not want it compounded with freezing temps. If the interior is kept dry and you have dry wood, your only issues will be a little more start up time due to the temp and humidity.

RT

[KEmerson]

Re: firing in cold/snow?

Thanks to you both. Secretly I have to admit that if it all went real bad and the oven somehow got destroyed I would be upset on one hand but then I'd get to build again on the other. There's some withdrawal after finishing the build and I'd love another shot at it. Unfortunately, it's likely I'm the only nut case in my circle of friends who even considered building an oven, so they get to enjoy my oven and are excused from building one of their own. Where's the fun in that? Well, to answer my own question, at least I get to do all the baking. If my friends built I might be alone whereas with the only oven anyone knows about I am getting requests for breads and dinner invitations. I must be the Little Red Hen. "Not I" followed by "I will".
Kim