4

Our home oven consistently undercooks food when we follow the recommended cooking directions.

Case and point: We just bought some chicken skewers from Costco. The directions say to cook them at 350F for 25-35 minutes. I just took them out after 35 minutes, and our digital probe thermometer read ~45C; well below the required 76C.

To measure, I found the thickest piece of meat I could find, and pushed the probe in, taking care not to go all the way through and touch the metal container that they're being cooked in.

I know it's likely not the oven not getting to temperature. It's a fairly new oven with a digital display that shows the current oven temperature (it was at 350F when I put them in). We also have a little bi-metal thermometer that goes in the oven itself. Last time we tested it, it agreed with the reading on the front of the oven.

It's also not likely the probe thermometers. We had 2 old bi-metal probes. I didn't trust them though (since apparently they can lose accuracy as the metal ages), so I went out and bought a new digital probe (mentioned above). After calibrating the 2 old ones one via the ice-water method and testing them on some chicken, all 3 probes agreed with each other within 2C.

We do live at a fairly high altitude (Calgary, Alberta, Canada [1,045 m, according to Google]), which if I recall, can mess with cooking times. I can't see that having this much of an effect though.

What are the possible problems here?

The oven:

Oven Front

Checking the temperature after it had been in for 45 minutes (10 minutes extra). Note it's only at 47.9C:

enter image description here

I just took them out again after 55 minutes, and it was only at 56C. I put them in for another 10 (which in total will have been an extra half an hour).

Community
  • 1
Carcigenicate
  • 551
  • 2
  • 6
  • 16
  • Are you pre-heating the oven fully before you put any food into it? Are you putting the exact same quantity into the oven as specified in the recipes (I.E. not a double batch)? – user132278 Mar 23 '16 at 00:38
  • 1
    Another question: was the food or any ingredients frozen prior to preparation? If so, is it fully thawed before you start cooking? – user132278 Mar 23 '16 at 00:39
  • @user132278 The oven was fully preheated prior to putting the food in. The cooking directions were for the entire "tray". And it was frozen to - 18C, but had been left out to thaw since 8 this morning (around 9 hours at room temperature). – Carcigenicate Mar 23 '16 at 00:42
  • 1
    Leaving food out at room temp for extended periods of time is extremely unsafe. I would not eat this food, regardless of it being fully cooked. – Catija Mar 23 '16 at 01:17
  • Anyway, 600 meters is the lower cutoff for "high altitude cooking", so I think it's definitely a factor. See: https://en.m.wikipedia.org/wiki/High-altitude_cooking – Catija Mar 23 '16 at 01:24
  • I don't think the altitude will make any difference when baking, as it's mostly affecting the boiling point of water. Furthermore, I've lived at an altitude of 1500 m and never noticed any difference when it comes to baking times or temperatures. – drat Mar 23 '16 at 02:01
  • 2
    @Catija, you may not. Many would. Don't forget that in a closed packet, starting from -18C, even the outermost surfaces will take quite a few hours to even reach 0C, let alone exceed 6C where you need to start worrying. This is especially true in an unheated (during the day at least) room. The guidelines ignore both the starting temperature and the room temperature, so are effectively based around a worst case. – Chris H Mar 23 '16 at 07:35
  • What's your room temperature during the day at the moment? If it's cool, the middle pieces may not have been fully defrosted especially if on an insulating surface such as wooden worktop. – Chris H Mar 23 '16 at 07:39
  • Also check your oven seal, if it is damaged, you may have a constant current of hot air flowing out (and cool air being pulled in). – Chris A Mar 29 '16 at 08:38
  • @Catija How would it be unsafe if it was fully cooked. As far as I know, bacteria don't become more resistant to heat the longer they're allowed to reproduce. That's how we've thawed food for the past 20 years, and the only food poisoning I've ever gotten were from fast food places. – Carcigenicate Mar 29 '16 at 15:00
  • @ChriH We keep our room temperature slightly above average. I can't quote what the exact temperature is. And there is noticeable heat around the oven door, so it may be a leak. – Carcigenicate Mar 29 '16 at 15:01
  • 1
    It is a grave misconception that cooking after leaving something out gets rid of all the bad stuff that may have reproduced in the interim. Just because you've been lucky for the past 20 years doesn't make it "safe". See related questions [here](http://cooking.stackexchange.com/questions/34670/how-do-i-know-if-food-left-at-room-temperature-is-still-safe-to-eat) and [here](http://cooking.stackexchange.com/questions/3472/is-there-a-problem-with-defrosting-meat-on-the-counter). – Catija Mar 29 '16 at 15:25

3 Answers3

3

Oven temperatures are conventions and really mean little. Plus, typical home ovens vary widely, so that when you set the dial to 350, the interior can easily fluctuate between 330 and 370, and that is when your oven is correctly calibrated, which few are! So, it is probably not getting to the temperature that the readout says. An oven thermometer can help get you in the ball park...but...no big deal...You are on the right track using a thermometer to measure the internal temperature of your food. Be sure to calibrate your probe thermometer to make sure it is accurate. Then, you are just going to have to get a feel for your particular oven, by setting the temperature a little higher and/or leaving food in a bit longer. Take note, and you should soon recognize a pattern that you can work with.

moscafj
  • 72,382
  • 3
  • 117
  • 207
2

Especially with a fan oven, opening the door can let a lot of heat out, so checking repeatedly can slow things down further. I assume you didn't test the meat with the door still open, that would make things much worse.

When you do check (at nearly the cooking time) anything tightly packed into the container like the skewers in your picture should probably be rearranged, so that those in the middle end up on the outside.

If you put a foil dish on a baking sheet to make it easier to lift out, preheating the baking sheet might help, especially if it starts quite cold. It can also take a while for an oven to come back up to temperature after adding something like frozen chips.

I also suspect that the middle of the inner skewers may have been very cold still, maybe even icy. I know defrosting in our utility room (not directly heated, probably around 12C in what passes for winter here) can take longer than you think. (BTW defrosting at the back of a fridge or in the meat drawer can take a very long time). This wouldn't be enough to explain the whole delay in cooking. As has been noted in comments, defrosting for hours at room temperature isn't recommended by some guidelines, but I and many others wouldn't think twice about it when the room is cool and the container closed.

I suggest that in this specific case a few factors combined to slow things down: the oven a touch under, the food colder than expected, and a lot of heat let out of both the oven and the food with repeated testing.

Chris H
  • 42,952
  • 1
  • 86
  • 147
2

Whenever you cook something, best to keep the times just as guidelines, and use a meat thermometer to measure what you are cooking. Also remember to take the meat out of the fridge to room temperature well before cooking it, to let it heat up. This will let the internal temperature of the meat reach the required temperature faster, with less oven/pan time and it will get you a better cooking result. If you also use a thermometer to measure the internal temperature of the meat before putting it in the oven, it will allow you to remove one variable from the equation.

Markus Mikkolainen
  • 161
  • 4