I set myself on fire! (tell me how)

Factual Questions
#1

Okay, not really, but I did lose all the hair on my arms and most of the hair in the bangs-area. Thanks to my trusty specs, my eyebrows are still mostly intact.

We had company over last night, and I made baked apples for desert. When there were about fifteen minutes left on the timer, I opened the oven to check them. There was a giant FOOF and I was hit with a huge wave of flame that billowed out of the oven the instant the door was opened, and just as quickly disappeared. The oven looked perfectly normal when I peeked in the door. Presumably there was some sort of ignitable fumes of some kind that were triggered with the pressure change or addition of oxygen when the door opened, but for the life of me, I can’t figure out exactly what happened. It’s an electric stove–I don’t even think we have a gas line to the house.

Mr. Armadillo blames the cinnamon in the apples–but I’ve baked cookies with more cinnamon. Here’s the recipe:
Four cored Gala apples
(stuffed with)
1 1/2 cups brown sugar
2 teaspoons cinnamon
1 teaspoon nutmeg
(mixed thoroughly)
This was packed into the core of the apple with a little well on top. I put a teaspoon of melted butter in the well, let it soak in, then packed the top with a little hill of the brown sugar mix. Dripped a few drops of burbon vanilla extract on top, and drizzled them with melted butter.
Then, I mixed 1/3 cup of organic apple juice with 2/3 cup brandy (actual recipe called for 1 cup brandy, no juice), and poured it over the top of the apples and into the bottom of the dish.

Bake for one hour in a deep ceramic casserole dish with a glass lid.

After the torching, I pulled off the lid, poked the apples, put them back in for the rest of the time, and pulled them out when the timer went off, with no further pyrotechnics.
Maybe the alcohol fumes built up inside the dish? Perhaps next time loosely cover with aluminum foil and fumes will burn off as they bake, rather than instant combustion?

So what the hell happened?

By the way, the apples were served with vanilla bean ice cream and were spectacular. Yum, yum. I’ll definately do this again. Maybe wearing a flame-retardant suit next time.

#2

Man! That sucks. Maybe there’s something flammable in apple fumes or something.

#3

I dunno, I mean it was recipe I found all over the internet, slightly modified–I didn’t add cloves or allspice, and used some apple juice rather than all brandy. The basic recipe can be found on about a bajillion different websites, and I can’t imagine there’s a lot of people out there with flame-throwing baked apples.

#4

WAG: The alcohol evaporated into the oven displacing the oxygen. The oven then got hotter, passing the kindling point of ethanol vapor. When you opened the door fresh air mixed with the flammable vapors that were already past their ignition point and phooof.

#5

If that’s correct, is there any way to provent said phoofing in the future? I’m rather fond of my eyebrows, and I’d like to hang on to them. But those apples sure were tasty.

#6

I concur with Eleusis

#7

Perhaps fermentation in the apples of the juice made alcohol fumes - maybe the alcohol base of your vanilla? Add oxygen with fumes and it flashed over.

Nice to see you weren’t hurt.

Now I’ve got to do some research on “burbon vanilla extract”. Sounds nice!

#8

Very hot smoke can spontaneously ignite when the oven door is opened. (we’ve all seen the trick where a freshly extinguished candle is re-ignited from a distance by lighting the thin plume of coherent smoke from the wick) Broiling in a less than clean oven can be a particular culprit. The coils of an electric broiler can heat smoke to 600-700F or more, in the oxygen-restricted confines of the oven.

A few drops of alcohol-based vanilla extract would be insufficient. 1 ml of pure ethanol (more than ‘a few drops’) generates ca .389 L (13 fl oz) of ethanol vapor at STP, and about twice that at 500F. Generally, oven flashovers from alcohol occur when there is an ample oversupply of alcohol, causing significant amounts (say 10+ liters/quarts) of vapor to remain after oxygen leakage is consumed. At 3.3-19% (by volume), the ethanol will actually explode. Most full-size household ovens are on the order of 150 L. Toaster ovens with volumes of a few liters, have been known to explode from smoke or alcohol, despite being deliberately “leaky”.

#9

Belrix you must have missed the 2/3 cup of brandy in the OP :slight_smile:

#10

Belrix, there was 2/3 cup of brandy in it too–but I was under the impression that the alcohol boiled off at a certain temperature.
burbon vanilla extract specs:
Spice Islands, pure vanilla extract (100% burbon vanilla), ingredients water, alcohol, and burbon vanilla bean extractive. Have no idea what that means, but it sure makes for tasty vanilla flavoring.

Postscript: out of curiosity, I called the 1-800 number on the bottle and asked–evidently “burbon vanilla beans” are the highest quality type of vanilla bean, and the burbon has nothing to do with the alcohol burbon. Just the name of the type of vanilla bean. Bummer. Still great vanilla extract–much better than the other types I’ve used.

#11

Yikes! So did this happen as a result of a dirty oven plus the 2/3 cup of brandy in the dish? The oven temp was set to 400, but if I’m understanding Eleusis, he(she?) suggested that the actual temperature was greater, due to the displaced oxygen? How do I prevent it happening again? You said “less than clean” oven–will simply making sure it’s very clean help? Or opening the oven door periodically to make sure there’s plenty of oxygen?

#12

maybe leave the oven door slightly ajar and adjust to a higher cooking temp? Or just crack the door every 5 minutes to release any fumes?

#13

Mmmmm, Brandy.

Yup - missed that line.

MixieArmadillo, When you mention “boiled off”, you have to ask, to where? Did the chimney burner on your stove (often the back-left burner it seems), have a cover or anything? Was your stove venting properly?

I sometimes make rum-raisin cookies, using a cup (or two) of real rum. The alcohol fumes rising off during the “boiling off” period are sinus-stripping fierce. I have to sample the scent like a chemistry major, wafting the fumes from the pot to my distantly-removed nose.

#14

Cleaning the oven will help, if it’s dirty. You can do a simple test by simply cranking it up to 500+ or using the broiler (with the door closed) for 5-10 min. You’ll probably know if its dirty enough to smoke up the joint without opening the door - which I’d recommend against: you’ll only risk your eyebrows and smoking up your house more than necessary. For this same reason, opening the door every 5 minutes may work, but is unnecessarily risky. Besides, it will screw up your suoffles, and impede cooking for other dishes, slowing some down, drying others, and generally wasting energy.

Really good cooks open their doors as little as possible, except during extended broiling in an electric oven [when they leave it open a crack] Even then, they don’t do it to prevent flashover [They keep their ovens clean anyway because a clean oven has more uniform heat radiation from the sides, cooking demanding dishes better] The reason they keep the door open a crack during extended broiling is to keep the oven from automatically cutting off the broiler when the temperature goes over 500F. Leaving the door open a crack allows continuous operation of the broiling element.

Were you seeking to bake the dessert or broil and carmelize it? I generally either simmer the brandy in the sauce on the stove beforehand or add it after the dish is cooked - but that’s just me.

BTW, I made a mistake. The equivalent volume of vapor for each ml of alcohol is 62.5% what I said it was (the density of ethanol vapor is 1.6x air, but I misread it as 1.0) To make up for this, I’ll tell you that the boiling point of ethanol is 173F (78.3C) and that its flash point is 59F (15C) . It can burn with an invisible flame and since its vapors are denser than air, it can travel along the ground to reach an ignition source (that’s a concern for factories, not kitchens)

The possibility of smoke flashover is one reason why self-cleaning ovens (which make a lot of smoke during cleaning) usually lock during the cycle. Exceptionally high cleaning temps are another reason.

The temperature of [some of] the vapor can much higher than 400F because the coils (or gas flame) are much hotter than 400F. If a small amount of vapor near the heat source superheats, it’ll ignite when the door is open, and in turn ignite the rest of the vapor.

The exclusion of oxygen is only important because the superheated vapors would oxidize as they were created, if extra oxygen were available. Without that oxygen, they become a powder keg waiting for a match - no, worse: they are the match; they just need air!

#15

I wasn’t paying much attention–there was a frenzy of cooking beforehand, then when I got dinner on the table, I tossed the apples in the oven and we sat down to dinner. There were several pots and pans on the stove, and a tea kettle sitting on the chimney burner.

#16

It’s a fairly new oven–we moved in at the end of August, and I believe it was replaced right before we got here. It certainly doesn’t smoke when I use the broiler. I think the only funk on the bottom is some kosher salt from the baked potatoes I made last week, and a smear of cookie dough which fell off the sheet as I was putting it in the oven–I pulled it out, but there’s still a smudge of it there. Anyway there’s not a bunch of food residue and dripped junk on the bottom.

**

I’m aware–so what do I do to prevent the flashover? Not use alcohol in sauces that go straight into the oven?

**

Is there a blank stare smiley? I was just following the recipe: core the apples, stuff with sugar/spice mix, add a little butter, pour brandy over apples, stick in oven at 400 degrees for one hour. I really don’t know much about what I’m doing. I enjoy cooking, but I was never taught how to do anything in the kitchen, so I’m sort of figuring all this out as I go along. [complete ignorance] Isn’t broiling done at a higher temperature, with both top and bottom burners going? If so, I imagine if it was supposed to be broiled, the recipe would have said “set oven to broil” or something similar–is there something I’m being completely clueless about? [/complete ignorance]

The recipe just said to pour it over the apples and put it in the oven, had I simmered it ahead of time to remove the alcohol, how long would I need to keep it on the stove?

Okay, so it sounds like this was a roundabout way of saying there needs to be a better oxygen flow into the oven to prevent the flash from happening again, no? If so, how do I go about ensuring that happens, so I don’t experience a hair-removing-wall-o-flame in the future? Never cook with alcohol? Ensure vents are working properly? cover the dish more loosely?

#17

1.6X? Yikes!

The alcohol gas might be so dense that it won’t rise to the top of the oven even when hot. Yep. Expand it 1.6x to make it equal the density of hot air. 1.6 times room temperature is 900F degrees. As long as the oven is below 900F, the gas would pour out of the apples tray and pool up in the oven bottom (and cover the bottom electric elements if the oven was set to “bake” rather than “broil.”

Wouldn’t the alcohol gas leave through the bottom vents? Not if the air as a whole was convecting the other way. The pool of dense gas might be enough to slow normal convection rather than reverse it. You might get slow jets of cool air coming in through any oven vents lower down, but the alcohol gas wouldn’t escape until it had thoroughly mixed with the incoming air. Or if convection reversed, it might be fairly slow (and incoming cool air would pool at the TOP of the oven, rather than mixing with the alcohol gas.) And if alcohol ignites at 790F, any oxygen in the gas pool near the hot electric elements would have already burned away. so the pool of dense gas could sit there unburned.

Leaving the door open a crack might not have done much if the opening is wide at the top and zero at the bottom.

Yep, as said in previous messages, disturbing the pool of dense gas covering the hot electric elements was like dropping a match into it.

Hmmm. I’ll have to try this as a demo. Boil some ethanol in an uncovered aquarium, place a red hot wire near the bottom, turn out the lights, then blow a puff of air at it and see if it goes FOOMP!! Oooo! Use a smoke-ring gun! Lob a “ring” of air into the alcohol pool so it strikes the hot wire.

That recipe looks like it has eyebrow-loss built in! Maybe it was developed by a cook using a gas stove.

To avoid fireballs you’d have to turn off the oven and let the heating elements cool below 790F before opening the door.

#18

If the oven was baking at 800 degrees, wouldn’t it have nuked the apples?

#19

Also: next time, could I simmer the brandy/juice mixture ahead of time to get rid of the alcohol gas before putting it into the oven? Is boiling on the stove sufficient to get rid of it? If so, for how long?

#20

I meant that the heating elements would have a temperature far above 800F whenever they’re glowing, even though the oven might be set to 250F.

If you opened the oven when the heating elements happened to be momentarily dark, then maybe they wouldn’t have ignited the pool of alcohol gas. (But maybe they’d still be far above 800F after the red glow disappeared.)

I don’t know how long it takes to boil away the alcohol. I’ve seen articles long ago that showed the alcohol content of food was not removed by normal baking. (So maybe it would cut the alcohol content in half, but not remove it entirely?)

Unless you want to use brandy flavoring extract, then probably the best bet is to turn off the oven for ten minutes or so before opening the door.

If it were MY kitchen, I’d yell “watch this!” then turn off the lights, then flap open the oven door. (Then the teletubbies all say Again! Again!) I should add this thread to my website http://amasci.com/weird/microexp.html. People with no microwave ovens shouldn’t feel left out.