Ready to eat food not suitable for microwave

Question

I bought a pre-made cornish pasty fromt the supermarket. The packaging says it can be eaten hot or cold, which presumably means it is already cooked. But the packaging also says it "is not suitable for microwave" and recommends 22 minutes in an oven at 200Cif it is to be heated. Why can't I heat it up in the microwave?

Asked by Ken

Answer

Because it is made from pastry dough. Pastry dough (and any other kind of dough) gets ruined by a microwave. See this question for details of what will probably happen.

The only exceptions for dough in the microwave is pasta (which is supposed to be boiled in water anyway) and some kinds of very soft batter, which can be eaten immediately as a "microwave cupcake" (I think they get unappetizing if left to stay for a while). Any other kind of dough is destroyed by the water escaping the starch as steam.

Answered by rumtscho

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Why can heating things in a microwave make them soggy?

Question

Why does heating something (like pizza) in an oven make it crisp but heating it in the microwave makes it all soggy?

Asked by Kaushik

Answer

Microwaves specifically heat water molecules in the food. This turns them to steam, and because the air in the microwave is actually cool, the steam then condenses. There is often not proper air circulation to move the steam away from the food. Often times the outside edges of the food will not be soggy, but rather burnt, because they receive more energy and the water can totally vaporize.

For better results when reheating food, do not reheat your food on "high" or the default power. Reheat it at a lower setting for longer time. For pizza specifically, I heat it in the microwave only to room temperature and then finish it in the toaster oven or in a pan.

Answered by smcg

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Is it okay to use a microwave in convection mode without the turntable?

Question

I just bought a muffin tin which is too large and certainly won't rotate on the turntable. My microwave doesn't have a "stop turntable" button. So is it okay if I remove it altogether and use just an oven rack to place my muffin tin on? Will it result in uneven baking?

Asked by Uday Kanth

Answer

I'm specifically answering your question "Is it okay to use a microwave in convection mode without the turntable?" -- Yes.

Your own answer points out the reality that if a pan is too large then the turn table will simply hit the sides of the microwave oven and then stop turning. There is nothing wrong with this. There is nothing wrong or damaging to have a metal tin touch the metal sides of your oven.

How was your baked items bottom? If you can sit your tin up so there is air flow under your tin, then you will improve the baking efficiency and it will bake more evenly.

CAUTION: If anyone else is reading this question and wondering about their own machine, then you really need to take caution about the "convention only" mode. You have to make sure there are NO microwaves in this mode or else your metal will conduct and you could have a serious explosion or break your microwave oven.

Answered by MADCookie

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Should I warm wine in the microwave?

Question

Although warming wine in the microwave might seem like a "horrible" thing to do it clearly has some practical benefits.

So will the microwave change the aroma of the wine compared to the conventional way or is it fine to do this**.

_{** Maybe before the guests arrive}

Asked by Besi

Answer

No, it won't change the aroma compared to conventional heating.

Generally, heating does change aroma. But it changes in the same way in conventional heating and in microwave heating (given that you heat to the same internal temperature, which can be very different time and power settings for different types of heating devices).

What microwaves change is texture. That's why the microwave is considered "a horrible thing" among chefs. You can't bake doughs or batters in it, and other things like vegetables can also suffer. Then there is the problem with uneven heating. None of these factors matter with liquids. You can warm milk, wine, whatever, in the microwave, without fearing a taste change.

Answered by rumtscho

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Why does flatbread have to be microwaved / cooked / toasted?

Question

I was eating at a sub making restaurant the other day and they asked if I would like my flatbread toasted... I responded with a "No thanks."

The Chef said, "Well technically the flatbread still HAS to be toasted, so would you like the meat toasted ?"

In confusion, I asked, "Why? I would prefer it un-toasted."

The Chef said, "We are required to toast all flatbread, as it releases some chemical... or something."

Can anyone clear up what he may be referring to? Does flatbread (non-homemade) HAVE to be toasted / cooked / microwaved ?

Edit:

Ingredients: Enriched flour (wheat flour, niacin, reduced iron, thiamine mononitrate (vitamin B1), riboflavin (vitamin B2), folic acid, malted barley flour), water, soybean oil, yeast, contains 2% or less of nonfat dry milk, salt, wheat gluten, sugar, dough conditioner (acacia gum, guar gum, ascorbic acid, L- cysteine, enzymes), calcium propionate, baking powder (sodium acid pyrophosphate, sodium bicarbonate, corn starch, monocalcium phosphate), and sodium stearoyl lactylate.

Asked by Foxtrot

Answer

If we're talking about the same sub making restaurant, their flatbread contains the following ingredients:

Enriched wheat flour (flour, niacin, reduced iron, thiamine mononitrate, riboflavin, folic acid, malted barley flour, ascorbic acid), water, soybean oil, yeast; contains 2% or less of: nonfat dry milk, wheat gluten, salt, dough conditioners (guar gum, Arabic gum, sodium stearoyl lactylate, enzymes), sugar, baking powder (sodium acid pyrophosphate, sodium bicarbonate, corn starch, monocalcium phosphate), calcium propionate.

I can see nothing in there that isn't in found in commercial soft white bread. It may well be a case of an overzealous legal department acting on the merest possibility of a hint of an idea that one ingredient may perhaps have the potential to maybe sometimes cause a problem if not cooked.

Answered by ElendilTheTall

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Does microwaving eggs kill salmonella?

Question

If eggs are thoroughly washed and of course beaten before microwaving, and after the process I can find no liquid, is there a possibility that salmonella is still there, or does it die from high temperatures?

Asked by Septagram

Answer

Microwaves do not kill bacteria, heat kills bacteria. The higher the temperature, the faster those bacteria will die off.

"Instant death" for most bacteria (including salmonella) is about 160° F (71° C). You only need a few seconds at this temperature. The notoriously strict USDA recommends 160° F for egg dishes but is considerably more lax about whole eggs and just says to cook until firm. Very few eggs are contaminated in the whites or yolks, so the risk is very low.

Pasteurization begins around 57° C (135° F), so many bacteria are killed before the egg coagulates (at 63° C / 145° F), which is why the USDA is not very strict about it; if an egg by itself is "firm" then it's generally already been hot enough for long enough to ensure safety.

Unfortunately, microwaves tend to heat (a) quickly and (b) unevenly, so if you are concerned about food safety and insist on making eggs in the microwave (not recommended), be sure to use short bursts and stir several times, otherwise you might end up with a combination of uncooked and overcooked parts, which is bad for food safety and for general taste and texture.

Note that there is not only a possibility but actually a certainty that some salmonella is still there, assuming that there was any to begin with. Cooking is equivalent to pasteurization and that does not kill every single bacterium, nor is it meant to; it just kills about 99.9999% of them which makes the cooked item safe enough to consume.

Answered by Aaronut

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Why did my banana catch fire in the microwave?

Question

Wow, that sounds like a silly question, but really! My wife froze bananas in the freezer with the peel still on. You can't peel them frozen. I put it in the microwave for one minute at 50% power. After 30 seconds the thin end of the peel (where a bunch connect to each other) was on fire, with a visible flame (about the size of a lighter). What on earth happened?

Asked by yossarian

Answer

It's caused by the high amount of potassium in the banana. Microwaves react with metals, bouncing off and cause arcing. You can even create a cool light show by putting a raw peeled banana in the microwave. Don't worry, it won't explode, but it will make a mess, it's also harmless.

This can also happen in some frozen vegetables depending on the soil conditions they grew in. As noted in the linked article, other high concentrations of metals such as magnesium, iron, and zinc can be the responsible mineral.

Momentary brief sparking is harmless and won't harm your microwave, but the USDA recommends turning off your microwave if you see sparks nonetheless. If it does start a fire, unless it's a very small fire, do not open your microwave door. The safest thing is to turn off the microwave and let the fire burn itself out by consuming all the oxygen. Opening the door could create a dangerous backdraft induced fireball.

Edit: Found a banana in microwave video.

See Also:

• http://www.scribd.com/doc/1697458/USDA-Microwave-Ovens-and-Food-Safety
• http://www.inspection.gc.ca/english/fssa/concen/specif/veglegmicroe.shtml

Answered by hobodave

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Can I prepare instant noodles in the microwave?

Question

I want to prepare instant noodles in microwave. The instructions on the pack clearly mention a gas stove to be used, but I don't have access to one.

The instant noodles I am talking about are Nestle's maggy 2 minutes (that's how they brand it in India). Have a look at the the following Google image search link if it still doesn't ring a bell.

http://goo.gl/tBwF0

Asked by Prafulla

Answer

The Maggi noodles you link to are just average ramen noodles, so can be cooked in the microwave quite easily.

1. Boil a kettle of water
2. Place the noodles in a microwavable bowl. You may need to break the noodles into pieces, but if you're careful with the boiling water you can sometimes soften the noodles in the middle enough to fold the block to make it all fit without breaking
3. Pour the flavour sachet (and any other curry powder/herbs) onto the dry noodles
4. Pour the boiling water onto the noodles, enough to cover the noodles, and if desired, a bit more for a bit of a soup
5. Put into the microwave, you can cover with a loose lid if desired, and microwave for around 2 minutes
6. Stir the noodles, separating any stuck-together blocks of noodles
7. Put back into the microwave for another 2-3 minutes (depending on your microwave's power)

I usually cook these kind in the microwave, since if I'm eating them I'm not usually in the mood for a proper cooking session. They do (depending on the kind of noodle) sometimes turn out slightly different when done in the microwave, as compared to boiling on hob, but both are nice as a snack.

Answered by dsample

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Will microwaving lemons make them easier or more efficient to juice?

Question

I've heard many people say that microwaving lemons before juicing them causes them to release more juice. I'm skeptical, although not enough so to ask this on Skeptics.

I cannot think of any physical reason why this should be so, and I don't believe it, but I would love to have some kind of response when people say this, or even to be proven wrong!

Asked by James McLeod

Answer

In my 900W microwave it takes 1/2 inch water 1 minute to boil and around 30 seconds to become hand-hot, (I know it may take a bit longer when heating a lemon with the skin acting like an insulator although this effect will be lessened due to the high oil content of the zest). You probably won't 'boil' the lemon however if you did it would produce by far the most juice as the water in the cells would turn into steam and burst creating a semi-juiced lemon before you've even cut it in half.

A cell membrane is made up of many intricate structures, one of which is fatty acid tails. When these melt the cell becomes more 'fluid' and becomes more permeable. This fatty acid melts at around 65 degrees. This would create a lemon that is a lot more flexible and juicy. Cell membrane diagram.

Based on this evidence, I personally would say that microwaving a lemon actually could help with juicing, the effect will be most noticeable when you're juicing a lot of lemons without a juicer.

Answered by Sebiddychef

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how long can i microwave microwaveable plastic containers for?

Question

I've got a microwave container and no oven and looking to cook some stuff - is it possible to microwave a container that's marked as microwave safe for 40 minutes or so?

Answer

A microwave-safe container shouldn't be heated significantly by the microwave (only by conduction from the food it contains). So, it should be fine, so long as the food is, and as long as the food doesn't exceed its allowable temperature.

You can test fairly easily—put the container, partially filled with some water, in the microwave for a few minutes. Does the container heat up, possibly more so than the water—especially where its not in contact with the water? If so, I'd be reluctant to use it in the microwave for that long.

Some containers are microwave safe, but only for heating to maybe 160°F or so. A common example is LDPE (often used for plastic wrap). Some can't take boiling for more than a short time (e.g., HDPE). Polypropylene should be fine, even with boiling. Go any hotter (e.g., filled with oil, which is probably insane) and most will fail. If you're lucky, the container will have a resin ID code on it, LDPE is #4, HDPE is #2, polypropylene is #5.

Your microwave may not be fine with 40 minutes of strait microwaving, or with the steam buildup. You should probably check its manual.

I assume also you've read Jay's comment about converting recipes, and that you're doing something where 40 minutes won't result in charcoal.

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Is there a way to cook hot dogs in a microwave without them bursting?

Question

Whenever I cook hot dogs in the microwave they invariably split and/or burst open. I've tried shortening the cooking time, but haven't found a happy medium where they are thoroughly cooked, but remain unmutilated.

Is there some trick to cooking them in a microwave without this happening?

Answer

Poke them with a fork in a few places. This will let the steam out in a controlled manner and prevent bursting.

or, even better, skip the microwave and boil them in a pan over the stove.

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Convection microwaves

Question

Are convection microwave ovens a useful item to have? Or are they not good as a microwave and not good as a convection oven either?

I understand that a regular convection oven helps to cook things faster. But a microwave cooks things pretty darn fast already so why would you want a convection feature?

Answer

It is a combination of a regular convection oven with a microwave, so you have both hot air and microwaves cooking your food. So the advantage is you get the quick interior heating of the microwaves combined with the surface browning from the hot air; convection just makes that hot air cooking faster and more even.

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Can I cook hamburgers in the microwave oven?

Question

What would be the main differences between frying hamburgers and cooking them in the microwave oven?

I'm stuck in a hostel with only a microwave oven and a water cooker.

Answer

In short, kind of, but only with the proper accessories/equipment. You'll never match a grill or griddle but you can get surprisingly close.

As was mentioned in other answers, what you're going to lose most is the sear.

I was given a Corningware Microwave Browning Dish a while back and found that it actually works pretty well when you're stuck with only a microwave. They were apparently popular when microwaves were new and exciting, but people didn't know how to use them well and they faded into oblivion. I've seen them on sale on eBay so you might be able to find a good price there if you're going to be stuck in the hostel for a while.

The basic idea is, there's a special kind of microwave-safe metal inside the base of the casserole. You heat this with nothing on it for 3 minutes to get it nice and hot. When you drop the patty on, it immediately sizzles. You use the microwave function to heat the inside, while the hot surface sears the outside. Although you're likely not going to get a perfect burger, you do get a real nice Maillard reaction on the outside of both sides (assuming you flip halfway) and if you play with the cooking time and power (to reduce that rubbery texture from overcooking), you can get something that's (in my opinion) a good 75%-quality burger compared to a griddle or grill. I actually burned pork chops on it once, that's how hot the surface gets.

As a bonus, similar to a nice Boos block, there is a gutter around the outside and the plate is slightly concave, so the juices run off into the reservoir and the burger won't sit in fat during the cooking.

After reading the other answers (ElendilTheTall's specifically), I would think if you combined the steaming method to cook the burgers, with the microwave browning dish to sear, you could probably get a really good result. If the burgers were fully cooked via steaming you could probably heat the dish and sear the burgers without even turning the microwave on (except to heat the casserole initially).

I believe Alton Brown did an episode where he talked about a specific type of brick that you can find at most hardware stores which is microwave-safe for the same searing purpose, but I can't find that info right now.

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Cooking frozen Pizza in the microwave

Question

I am totally new to cooking, I just boil eggs :). I am staying alone for sometime, and I want to cook some stuff at home instead of eating outside every day.

I thought that Pizza might be a good start. So, I am trying with pre-made frozen pizza (well, that is not actual cooking!)

The problem is that all the frozen pizzas I found are created to be cooked in oven (put 15 minutes in the heated oven), and my oven is broken. I have the fan grill, the oven top and a microwave..

can I cook pizzas using any of these?

Answer

No, you can't bake pizza in the microwave. See Why do my pizzas get such hard crusts? for details. The short answer: it gets as hard as brick.

I won't say that baking a pizza with a stove and a grill is impossible, but it is definitely not something for beginners. So this, too, is out. Really, a pizza needs an oven.

If you insist on pizza, the cheapest way is to buy a toaster oven. They start at 50 €.

If you just want to ease into cooking by preparing pre-made food, look into frozen pre-seasoned vegetable mixes for the pan, or fresh dumplings from the refrigerated goods aisle, or noodles with easy sauces. All of these can be prepared without an oven, and don't need much time or cooking knowledge. They won't let you experience all the benefits of home cooking, but neither will frozen pizza, so this is probably not a problem in your case.

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Baking cakes in the Microwave ovens as compared to Electric ovens

Question

Is there a difference in the output or in the procedure when baking cakes in the Microwave ovens as compared to Electric ovens?

What are the basic and crucial differences found among cakes baked in the above mentioned different equipments?

Answer

Yes, there is a difference. You shouldn't be baking a cake (or anything else) in a microwave oven.

A microwave oven excites the water within your food. When you put in dough or batter, the excited water doesn't bind with the starch the way it does under normal heat, it escapes the starch, leaving you with a stone-hard piece of dough or batter.

There is something called "five-minutes microwave cake". I haven't tried it, but in the recipes floating around the interwebs it gets eaten while still hot (so probably before it has had the chance to get too hard). It also seems that there is a very small heat frame in which it gets OK. Bake it too much, and it will get hard, or burn. Bake it too little, and you end up with a mug of warm batter. It is also supposed to be a cupcake, I suspect that if you try to bake a bigger portion at once, there will be enough temperature difference in different zones of the batter to get underbaked, baked and hard portions all at once.

Bottom line: if you want to try for the fun of it, make a cupcake in the microwave, and watch your energy input (microwave watt setting and time) very closely, then eat immediately. You can find recipes all over the Web, e. g. on Instructables. If you want a real cake, don't bake in a microwave.

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Cooking pasta in the microwave

Question

I have a microwave "pot" that I use for steaming vegetables. The instructions say it can also be used for cooking pasta, which seems sacrilege to me.
Does anybody know if the result would be a good al dente pasta if cooked in the microwave? I'd hate to waste a batch of my home made pasta just to try it.

Answer

You know, I'm right there with you on the sacrilege part, but nowadays I microwave pasta all the time. You need to use a non-starchy pasta for this to work. I use plain store-bought Barilla Plus because I love it anyway. For fresh pasta, you could try a small experiment; I've never tried with freshly-made pasta.

It takes less time than boiling on the stove for me because I do this:

1. Fill up the electric kettle with water and turn it on.
2. I use a 1/2 gallon Pyrex measuring cup as my "pot", and I put an inch or so of water in that and pop it in the microwave for four minutes to warm it up.
3. When the water's boiling in the kettle and the oven timer expires, I take out the Pyrex container, add the pasta and a little oil and some salt (optionally a little vinegar), and then pour in the boiling water to cover by an inch or so.
4. Dumpling-like pasta (rotini or penne) take about 8:30 to cook on high (I've got I think an 1100 watt oven; experiment); spaghetti 5:30, thin spaghetti 4:30.

I know it sounds like a horrible sin, but I started doing it when I needed to cook small portions of pasta for my kids. I tried it myself, and realized that I could tell absolutely no difference from the results I got in my big pasta pot. When I need to boil a lot of pasta (like 2 14oz boxes) I still use the big pot of course, but a pound or less actually cooks up perfectly fine. My pasta cooker is enormous and takes a long time to come up to the boil.

Now once I tried this (not thinking clearly, obviously) with some very starchy, fancy pasta, and it did not work at all. But maybe because it's got so much extra protein, Barilla Plus comes out absolutely fine. (It's good for you too.)

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Sugar forming tiny bubbles in microwaved coffee?

Question

When I heat up coffee in the microwave and then pour in sugar, a layer of tiny dense bubbles forms at the top of the glass and stays there for the duration of the drinking, diminishing slightly over time. When I prepare the coffee by other means of heating this does not happen. What causes those tiny bubbles?

Answer

Upon addition of sugar to the superheated coffee, the formation of bubbles (phase transformation) occurs because the fine particles of sugar provide sites for the heterogeneous nucleation of gas from the liquid.

When the introduction of a fine inoculant (such as sugar particles) results in sudden fizzing of a liquid, it is an indication that there has been minor superheating of that substance.

Superheating tends to occur more in microwaves than on stovetops because people use metal saucepans/kettles on the stove, while generally using glass or glazed ceramic containers when heating a volume of water in a microwave oven.

When water is heated in a glass or glazed ceramic container rather than a metal one, the very hard surface of the container means that there are few scratches on it to act as sites for the heterogeneous nucleation of gas. Fewer heterogeneous nucleation sites means less heat loss through the transformation of liquid to gas.

This university site also makes a good point about the tendency for stovetop heating to cause localised superheating in the vicinity of the container walls... However, I think that this would tend to cause more boiling due to localised heating to the point that homogenous nucleation can occur (with the homogeneously nucleated bubbles then acting as further heterogenous nucleations sites) – not because of stirring of the water.

With regard to why your bubbles remained present for the duration of drinking, I would hypothesise that this perhaps has something to do with the oils in the crema of the coffee, and/or reaction of the dissolved sugar to form something that increases the surface tension of the water. (Not sure what you would call the opposite of a surfactant effect).

A final thing I would like to mention is that (as indicated on the UNSW page), microwaving liquids has the potential to result in violent reaction, or even explosion, of the liquid — in other words, you are risking serious burn injuries by taking a shortcut to heat it up.

Adding a powder (like sugar or instant coffee) to superheated water is particularly bad because in doing so, you are introducing millions of nucleation sites at once. That said, you should also be aware that since gas bubbles themselves promote heterogeneous nucleation, simply placing a spoon in the cup can be enough to cause an 'explosion'.

If you really need to microwave a liquid, (e.g., if you are cooking something), consider heating it in a microwave-safe plastic container that has been washed a few times (and is therefore abraded on the inside). You should also stop the microwave to check the temperature of the liquid at regular intervals, rather than nuking the fluid for an excessively long time.

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Unbreakable microwave safe plates?

Question

I'd like to have plates with the following characteristics:

1. Don't break when you drop them on the floor
2. Do not get hot in the microwave (like normal china)
3. Durable and washable (not paper plates)

Do such plates exist? If so, where might I obtain some?

(edit) Ideally they would also look more or less like standard dinner plates.

Answer

One thing that hasn't been mentioned -- Corelle.

It's not completely unbreakable (and much like Pyrex, when it goes, it goes like what nico mentioned -- little tiny shards everywhere).

Supposedly, it loses its resilience to breaking over time, so newer plates are less likely to break when dropped as older ones, so this is one case where buying at a yard sale might not be best.

I don't know how the durability compares to Pyrex plates, but it looks more 'dinnerware-like' to start.

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Why do marshmallows poof up so huge when put in the microwave?

Question

As anyone who's put marshmallows in the microwave knows, they expand a ton! Sometimes they puff up to literally more than twice their original size (YouTube video for those who haven't seen it).

So, why?
At first I assumed it was because they had a lot of air in them, but that doesn't make sense. There's no way that amount of air can puff up that much from the heat!

What makes marshmallows poof up so much when they are microwaved?

Answer

Marshmallows expand so much because the water in them becomes steam, and gas takes up a LOT more volume than liquid. Specifically, 1 mL of water becomes ~1.36 LITERS of vapor, before it gets heated further. That's 1000-fold expansion, before you add additional expansion as the gas is heated.

Marshmallows don't have all that much water content, but when it's trapped in a stretchy gelatin matrix that holds gas readily, it only takes a bit to blow the whole thing up like a balloon.

You are correct that the gas expansion on its own is insufficient; unless I've badly muddled my calculations, gas expansion from 20C to ~150C (caramelization temperature) will increase the gas volume by under 50%.

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Why do frozen greens get fibrous and tough in the microwave?

Question

When I microwave frozen spinach or amaranth greens to cook them, they sometimes get tough and fibrous. There doesn't seem to be a consistent pattern in when this happens, so I can't figure out how to avoid it.

So I ask you: why do frozen greens get tough and fibrous when cooked in the microwave, and how can I avoid it?

Answer

Microwave ovens cook primarily by spinning water molecules. Frozen water is less susceptible to this affect. I would guess that with certain vegetables, as frozen water turns to a liquid, it is quickly heated to the point that it boils and evaporates. The heating is less even than cooking frozen vegetables in a pot and leads to areas that are somewhat dehydrated and fibrous.

Try cooking your frozen vegetables in a container with a lose cover and additional water. This will allow them to cook or steam from the the outside in much like in a pot.

http://en.wikipedia.org/wiki/Dielectric_heating

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