Two questions from a wannabe cook

[Jennifer Murphy]

I have always wondered about these two "rules" of cooking:

1. Preheat the oven before putting the food inside
My Internet search seemed to say that it is to prevent food from heating too slowly, which allows bacteria to grow. If I am following a recipe, I will always preheat, because there is plenty of time while I am getting ingredients together. But when baking a potato, I don't bother. I use a temperature probe, so the potato will reach 212°, which is well above the bacteria range of around 130-140°. Correct?

2. And speaking of potatoes, do I really need to poke holes before baking? And if so, how many and how deep?

Thanks

 

[Andy M.]

Preheating so the oven is at the proper temperature before you put the food in the oven is more important for baked goods than for a potato or roast meats. An oven would have to preheat VERY SLOWLY for bacteria to be an issue.

The oven is properly preheated NOT when it beeps but 10-15 minutes after the beep to ensure all areas and surfaces are evenly heated. If you're baking a pizza with a pizza stone, let the oven run at temp for an hour after it beeps. It takes a long time to heat a pizza stone.

Yes. Poking holes prevents exploding potatoes when baking. I use the tip of whatever knife I'm using at the time and stab the potato 5 times about ¾" deep. Baking to an internal temp of 210ºF-212ºF is right on.

 

[Silversage]

What Andy said.

Baked goods are different. Many baked goods need the instant burst of heat to kickstart the leavening agent (yeast, baking powder, baking soda, eggs). But roasting and braising don't need that bump. Even if they are slow to warm, the ultimate time/temperature will kill any bacteria.

The important reason to pierce potatoes is to let the steam escape so the skin doesn't burst in the oven and explode. All you need to do is a few shallow punctures.

 

[jennyema]

That’s one weird internet search. There is literally no modern oven that takes two hours to heat to 140 degrees.

Preheating is not about food safety.

 

[Jennifer Murphy]

That’s one weird internet search. There is literally no modern oven that takes two hours to heat to 140 degrees.

Preheating is not about food safety.

I thought it was a little off. That's why I asked. Here's one of the sites:

https://www.realsimple.com/how-long-does-it-take-an-oven-to-preheat-7510632

 

[caseydog]

I have always wondered about these two "rules" of cooking:

1. Preheat the oven before putting the food inside
My Internet search seemed to say that it is to prevent food from heating too slowly, which allows bacteria to grow. If I am following a recipe, I will always preheat, because there is plenty of time while I am getting ingredients together. But when baking a potato, I don't bother. I use a temperature probe, so the potato will reach 212°, which is well above the bacteria range of around 130-140°. Correct?

2. And speaking of potatoes, do I really need to poke holes before baking? And if so, how many and how deep?

Thanks

I do the same thing with a baked potato as far as not preheating. I don't see any point.

As for poking holes... YES!!! I've had a potato explode in my oven once, and only once. I learned my lesson. What a mess that thing made.

CD

 

[jennyema]

I thought it was a little off. That's why I asked. Here's one of the sites:

https://www.realsimple.com/how-long-does-it-take-an-oven-to-preheat-7510632

That information is incorrect, sadly. Real Simple should have fact checked it with a food scientist.

But I'd suggest always pre-heating an oven if your recipe tells you to and cooks to TIME, not temp (in other words, it tells you to cook something for 20 min rather than cook till it's 200 degrees).

I'd also suggest pre-heating the oven when you are cooking proteins.

 

[jazzerlord]

I have always wondered about these two "rules" of cooking:

1. Preheat the oven before putting the food inside
My Internet search seemed to say that it is to prevent food from heating too slowly, which allows bacteria to grow. If I am following a recipe, I will always preheat, because there is plenty of time while I am getting ingredients together. But when baking a potato, I don't bother. I use a temperature probe, so the potato will reach 212°, which is well above the bacteria range of around 130-140°. Correct?

2. And speaking of potatoes, do I really need to poke holes before baking? And if so, how many and how deep?

Thanks

When it comes to baking potatoes, as you mentioned, they are heated to 212°C. This high temperature is sufficient to kill most bacteria, including pathogens. It is considered safe in terms of bacteria elimination.

 

[Linda0818]

Hmmm... I've never once poked holes in my potatoes before I bake them. Or when I microwave them, for that matter. Never had a potato explode.

*knocking on wood*

Sometimes I put the potato directly onto the rack (with the exception of sweet potatoes, since they release moisture when they bake) and other times I'll set it in a cake pan, if I've oiled and salted it.

 

[caseydog]

Hmmm... I've never once poked holes in my potatoes before I bake them. Or when I microwave them, for that matter. Never had a potato explode.

*knocking on wood*

Sometimes I put the potato directly onto the rack (with the exception of sweet potatoes, since they release moisture when they bake) and other times I'll set it in a cake pan, if I've oiled and salted it.

I put mine right on the rack, with a probe thermometer in it.

I can assure you that if you do have one explode, you will not be a happy camper.

CD

 

[Linda0818]

I put mine right on the rack, with a probe thermometer in it.

I can assure you that if you do have one explode, you will not be a happy camper.

CD

Trust me, I've had enough kitchen disasters to last me a lifetime, including almost burning down my MIL's kitchen many years ago.

It's funny now, but it wasn't funny then.

 

[larry_stewart]

I poke holes with a fork to allow the steam out, and provides a crispier skin on the outside . I take out , brush with oil and put back in for the last 10 minutes or so.

 

[Sir_Loin_of_Beef]

Hmmm... I've never once poked holes in my potatoes before I bake them. Or when I microwave them, for that matter. Never had a potato explode.

Not only have I had a potato explode in the microwave, I had a sweet potato catch fire in the microwave when I was cooking without looking!

 

[Jennifer Murphy]

When it comes to baking potatoes, as you mentioned, they are heated to 212°C. This high temperature is sufficient to kill most bacteria, including pathogens. It is considered safe in terms of bacteria elimination.

Most? Can any bacteria survive being heated to 212°?

My sous vide booklet tells me that 140° and above is safe. If that is correct, then I would think that a potato that goes from room temperature to 212° over 1-2 hours, at least half of that over 140°, would be totally free of living bacteria. No?

 

[Jennifer Murphy]

I put mine right on the rack, with a probe thermometer in it.

I used to bake potatoes on a baking sheet. Now I just put them on the rack. I can't tell any difference in the result ad the potatoes (russet) don't seem to leave any residue.

 

[Jennifer Murphy]

Trust me, I've had enough kitchen disasters to last me a lifetime, including almost burning down my MIL's kitchen many years ago.

It's funny now, but it wasn't funny then.

When I was in high school, we had a little kitchen disaster. My mom always turned the stove on high to get it warmed up more quickly. One day, when I was in the basement doing something, she called to me saying that she had just put something on the stove and to come up in 5 minutes and turn it down. She needed to run to the store. Of course, I totally forgot. At some point, I heard a loud bang. I went upstairs to find the kitchen filled with what looked like fog. Through the fog, I could see the burner on the stove glowing red. When I took a breath, I almost choked. I opened the side door, took a deep breath, and went over the turned the stove off. I then went back in several times opening doors and windows to let the toxic fog out.

When it finally cleared, I saw that the bottom of the large heavy pot that she used for pot roasts had melted. The "fog" was actually a toxic metallic haze. The kitchen and the adjoining living room had to have all new paint and wallpaper and I think some of the furniture had to be replaced.

 

[Jennifer Murphy]

I poke holes with a fork to allow the steam out, and provides a crispier skin on the outside . I take out , brush with oil and put back in for the last 10 minutes or so.

I have tried rubbing the potato skins with oil and butter before baking. It makes the skins softer, but not better in my opinion.

Does adding the oil in the last 10 minutes do something different? What kind of oil?

 

[caseydog]

Most? Can any bacteria survive being heated to 212°?

My sous vide booklet tells me that 140° and above is safe. If that is correct, then I would think that a potato that goes from room temperature to 212° over 1-2 hours, at least half of that over 140°, would be totally free of living bacteria. No?

Killing bacteria is a time/temperature equation. Bacteria is pretty much dead a 160F in a matter of seconds. With sous vide, you can cook something like pork to 135F, if you cook it for long enough. At 135F, bacteria takes longer to die.

I don't know why we are even talking about 212F in regards to food safety.

CD

 

[GotGarlic]

Most? Can any bacteria survive being heated to 212°?

My sous vide booklet tells me that 140° and above is safe. If that is correct, then I would think that a potato that goes from room temperature to 212° over 1-2 hours, at least half of that over 140°, would be totally free of living bacteria. No?

Bacteria will be killed at 160F, as Casey said. There are other pathogens that can survive that temperature, such as botulinum. But it can only reproduce in an oxygen-free environment, so it's not a concern unless you're talking about canning.

 

[taxlady]

Bacteria will be killed at 160F, as Casey said. There are other pathogens that can survive that temperature, such as botulinum. But it can only reproduce in an oxygen-free environment, so it's not a concern unless you're talking about canning.

I was going to mention that. As I understand it, the bacteria die at regular bacteria killing temperatures. It's the spores that don't die until higher temperatures, higher than 212°F. But, as GG mentioned, the spores need an anaerobic environment to make the toxin.