The microwave ready meals I tend to eat all say the same thing: pierce the protective plastic cover before heating at %POWER%, usually around 800W for %TIME%, usually 4-5 minutes. Most of them say to use a fork to make around half a dozen holes in them. I've tried using a fork multiple times and it usually just gets stopped by the plastic, sometimes even bending the container around it. My forks might be too blunt...

My usual way now is to stab in a dozen small holes all over with the tip of a cheap paring knife, often even straight through any paper label that's glued onto the plastic, to ensure a proper spread. That does the job, but I wonder if I'm making holes that aren't big enough, or that I'm making too many holes, or that they're the wrong shape. I've also in the past tried to open up a corner of the packaging, but last time I tried it, with a paella, the rice felt noticeably dryer.

I'm probably overthinking this, but the question I have is: are there general guidelines for piercing this cover to improve the heating process?

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    Your forks are insanely blunt if you can't get it through the foil. I genuinely manage to do it with the back of a spoon.
    – Flater
    Commented Sep 26, 2023 at 5:36
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    "and it usually just gets stopped by the plastic, sometimes even bending the container around it" Are you trying to push a fork through the foil, rather than stab it? That's the only thing I can think of why a (metal) fork can't get through.
    – Flater
    Commented Sep 26, 2023 at 5:45
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    "Most of them say to use a fork to make around half a dozen holes in them" - your instructions are way more specific than what I'm used to, but I suppose this varies by country (for regulation) and manufacturer (for their preference). For the reasons described in the answers I reckon you need one hole (for steam) and you want more (as a backup, since a hole could conceivably get clogged, or the plastic could touch the food and create a sealed-off area with no hole where some steam collects). How you make the holes doesn't matter: size of hole might matter a little bit. Commented Sep 26, 2023 at 19:28
  • @Flater Yeah, my forks are quite blunt. I'll see if I can add a picture.
    – Nzall
    Commented Sep 27, 2023 at 9:33

7 Answers 7


I assume it is simply to allow some steam to escape during heating, so that you don't have a big mess to clean up when the "balloon" pops, or, as Chris H wisely points out below, a potential burn when you unseal the container after heating. I think your strategy of poking a hole with a knife a couple of times will be sufficient.

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    I've always used a knife, or a sharp metal skewer. Forks are almost never sharp enough. If a balloon formed and didn't pop by itself, you'd get showered with hot food when you peeled back the lid, possibly extremely hot as the top can be much hotter than the bottom. That could easily mean burns, not just a mess
    – Chris H
    Commented Sep 25, 2023 at 18:32
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    @ChrisH good point...edited.
    – moscafj
    Commented Sep 25, 2023 at 18:51
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    @ChrisH: What kind of forks do you and OP have that can't pierce a plastic foil? This has never even come close to not piercing the foil in my experience.
    – Flater
    Commented Sep 26, 2023 at 5:42
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    @flater some quite chunky IKEA ones with rather square ends to the tines. They'll go through with enough force, but you need to put the plastic tray down on a solid flat surface as it will bend so much, and the force required seems a little unreasonable. It's far easier to get a steel skewer from the same drawer (which happens to be under the microwave) and poke gently, with no need to put the container down
    – Chris H
    Commented Sep 26, 2023 at 5:52
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    I wonder also if different brands have different films and trays. Mine are most likely to be UK supermarket own brand, from the fridge
    – Chris H
    Commented Sep 26, 2023 at 6:15

2-in-1 Trick: Don't Pierce, Lift a Corner of the Cover.

While piercing the cover to allow steam to escape is the recommended approach -- on the packaging -- it's not the best solution.

The next step, once the meal is heated, is to peel the plastic cover completely, so you can access whatever is inside. Except that now the container is hot, the plastic cover is hot, and you're burning your fingers if you try to peel it by hand. A few knife cuts to get most of the cover out of the way is a possibility, of course, but those leftover bits of plastic get in the way when tipping the container...

Instead, I therefore prefer to pre-lift one of the corners of the plastic cover prior to heating:

  1. It lets steam escape, just as piercing the cover would.
  2. Once the container's hot, I can relatively easily peel the cover, without burning my fingertips.

You'll want to peel the cover not diagonally, as it tends to tear up, but instead following the edges (where it's "glued") going clock-wise or counter clock-wise.

The technique is especially valuable if you have a "multi-parts" meal. If you make holes everywhere, you won't be able to tip the container afterwards without the content leaking through the holes. By lifting corners, however, you can peel the cover for a single part at a time, and tip the container to your heart content. This makes it much easier to present the meal nicely on a plate.

Note: if you have multiple parts independently sealed, you need to lift at least one corner per part...

  • Agreed, with one caveat: lifting corner(s) prevents you from shaking/agitating the meal half-way through to stir/redistribute the contents for more even heating. (IME, even if you hold the corners down firmly, some of the sauce always escapes.)
    – gidds
    Commented Sep 27, 2023 at 17:35
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    @gidds: Don't holes in the cover also prevent you to do so? Commented Sep 28, 2023 at 6:50
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    In my experience, if the holes aren't too big (i.e. you use a fork rather than a knife, and don't stab too enthusiastically!), and you don't shake too hard, then no, holes don't stop you agitating.
    – gidds
    Commented Sep 28, 2023 at 7:46

It would be difficult to poke too few holes. The purpose is to allow steam to escape, preventing a potentially dangerous buildup of pressure and hot steam. Even a tiny hole should allow pressure to equilibrate, and the slightly elevated transient pressure during cooking won't make much of a difference. At worst, you might need to leave the food in the microwave another couple seconds after the elapsed time to let built-up steam escape. Personally, I have never seen a microwave meal explode even without holes poked in it.

Putting too many holes in the film could cause the food to cook improperly if the steam simply escapes rather than cooking the food.


I suspect that the problem piercing the plastic with the fork is because of the way you are holding the fork.

When you pierce the plastic with your fork, angle the fork so that one prong of the fork hits the plastic first. That way when the full force of the initial impact is concentrated in a small area which will pierce the plastic. If the fork is perpendicular to the plastic then the force is distributed among the typically three or four prongs, so you would need three or four times the force on the fork to have the same effect.


There are two purposes for the holes - first, as others have pointed out, is to allow steam to escape. Second, the heated steam itself assists in cooking the food. So on this second point, I poke my holes near the center of the tray. Since microwaves heat from the outside in, the centre of the tray would heat the least, so directing the steam towards the middle of the tray would help the food heat more evenly.


I used to hold the fork by its handle, but it got messy occasionally, and for that reason used to go for a sharp knife.

One day it dawned on me to hold a fork near the end of the prongs, and slanted at an angle as if the single prong that I use to pierce with is an extension of my index finger and my thumb held together. Basically in this position I can sense/orient my hand, my fingers, the fork and the plastic well, and I get a lot of control with my hand and fingers. This allows me to use just the right amount of force to break open the film, not to mention it's safe compared to using a knife.

There may be other positions to hold the fork that are mechanically more efficient, but may not give you the same degree of control for your motor system to react in real-time to packaging variations.

I usually punch around a dozen holes, but it's more habit than a determination of an optimal number.


Since I live alone I do a lot of stuff in the microwave and have found a sharp knife works best. To appease my slight OCD place 6 evenly spaced. Since most of my food is frozen the solid mass stops the knife going in too far - the slit is normally between 2mm and 4mm long. When doing non-frozen I simply pull back as soon as the blade pierces the film although this does tend to give longer slits. This also works when doing a portion of frozen veg in an old ready meal container covered in micro safe cling film.

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