Wikipedia:Reference desk/Archives/Science/2016 February 5

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February 5

When the freezer or refrigerator breaks, what do I do with food in it?

OK, so something is wrong with my refrigerator and freezer. I have no idea what, but I am calling the repairman tomorrow. There is nothing that I can do about it now, overnight. Basically, both parts (the fridge and the freezer) are not "cold enough" and something is causing the refrigeration and freezing to not work properly. Dead motor? Who knows? So, my question: do I have to throw all of that food out or will it be OK? And the food in the freezer, can that simply be re-frozen again? Right now, the freezer "seems" like a refrigerator (in temperature). Thanks. Joseph A. Spadaro (talk) 07:36, 5 February 2016 (UTC)

The answer depends on the items that have defrosted. General advice is NOT to re-freeze, and this should be strictly followed for any meat items that have thawed, especially if they have been thawed for some time. Some foodstuffs can be refrozen, but if in doubt, either eat or throw out. Ice cream doesn't re-freeze. Please note that this is opinion, not expert advice on a health issue. If in doubt, throw it out. Dbfirs 07:46, 5 February 2016 (UTC)

Mostly frozen dinners. Joseph A. Spadaro (talk) 08:27, 5 February 2016 (UTC)

Specifically, refreezing ice cream leads to formation of ice crystals, so it no longer has that smooth texture you would like. However, when you are ready to eat it, you can let it melt and basically make a milk shake. (Also make sure it hasn't been left warm long enough for bacteria to grow.)

Bread can be refrozen, but doing that too many times will lead one side to be soggy and the other to be stale.

Soup can be refrozen with no bad effects, although when you reheat you may want to boil it to kill off any bacteria.

Most of those frozen dinners are probably OK. I'd cook them normally, smell and taste them, and if they seem OK go for it. StuRat (talk) 16:23, 5 February 2016 (UTC)

So would I, especially if they have never reached room temperature, but I wouldn't advise anyone else to do this, just in case ... Dbfirs 18:58, 5 February 2016 (UTC)

Also, if you are a smoker, or otherwise have an impaired sense of smell and taste, have somebody else smell and taste it for you. StuRat (talk) 15:26, 6 February 2016 (UTC)

The idea that you can't refreeze meat or other foodstuff is common, but it's a misconception (which doesn't mean that all thawed food can be refrozen safely or without changes in texture and taste), see [1] [2] [3]. Sjö (talk) 09:43, 5 February 2016 (UTC)

It's worth mentioning that some home-owner's or renter's insurance will cover you for the loss of food in your freezer when it fails and can't be repaired within a few hours. If you plan on claiming, take a photo of the food packages that you are tossing out. SteveBaker (talk) 14:25, 5 February 2016 (UTC)

Some things that might cause a freezer/fridge to work, but at reduced cooling, are loss of coolant, coils in back covered with dust bunnies, or air flow to them reduced in other ways, or something wrong with the thermostat. You might try turning the thermostat to the lowest temp, and blowing a fan on the coils, until the repairman arrives. Also try not to open the door often, and you could pack ice or maybe dry ice inside to keep it cool. (Make sure the regular ice has a safe place to drain.) Also, if there was ice buildup inside the freezer (in a non frost-free model), ensure that you don't get puddles underneath when that melts. StuRat (talk) 16:31, 5 February 2016 (UTC)

So now it is the case that the repairman cannot come for several days (Monday). That will leave the food for more than three days (all of Friday, all of Saturday, all of Sunday; plus part of Thursday and part of Monday). Will those frozen dinners still be good at that point? Or is that too much time? Thanks. Joseph A. Spadaro (talk) 19:13, 5 February 2016 (UTC)

If you could keep them at fridge temperature or below, then they might still be OK, but if they remain near room temperature for three days, then they should definitely be thrown out (those you haven't already eaten). Does your insurance not cover this loss? Can you find someone else with spare space in their freezer? Can you buy any ice and a large cool-box? Dbfirs 19:20, 5 February 2016 (UTC)

Thanks. I had assumed that the repairmen would come out the same day; I guess that's not the case. They are not free until Monday and, of course, there is the intervening weekend days. I will bring the food over to some relatives who live very close by. Thanks. Joseph A. Spadaro (talk) 20:54, 5 February 2016 (UTC)

I suggest using the freezer itself as the "cool box". It's reasonably well insulated and you won't lose the existing "coolth" when doing a transfer. The downside is that the freezer isn't meant to hold water, so you should use dry ice instead of normal ice. You can get that at many grocery stores and even gas stations. You could also ask neighbors if you can stow some food there until Tuesday. StuRat (talk) 21:14, 5 February 2016 (UTC)

Coolth μηδείς (talk) 22:43, 5 February 2016 (UTC)

Yes, I would like this to become a common word. While physics tells us that "coolth" is only an absence of warmth, that doesn't mean we can't have a word for it. By comparison, you can say "it's dark outside", not having to resort to something as ugly as "their is a paucity of light outside". Of course, there is "cold", but like warmth is less extreme than hot, so is coolth less extreme than cold. StuRat (talk) 23:31, 5 February 2016 (UTC)

1540s, from cool on the model of warmth. It persists, and was used by Pound, Tolkien, Kipling μηδείς (talk) 02:47, 8 February 2016 (UTC)

... and the OED shows usage from 1547 onwards, but it does also comment: "Now chiefly literary, arch., or humorous". Dbfirs 10:04, 6 February 2016 (UTC)

• Joseph, 10 lb bags of ice cost $2 each. You also presumably have neighbours who can hold stuff temporarily? My parents lost power on the June 23rd storm that devasted South Jersey, leaving them without power for 72 hours. The following morning I bought as much ice as I could find, and we stuffed their upright freezer, ice on top, food on the bottom racks, and towels in the bottom. My dad cooked a rib-roast and a ham sooner than he had planned. But there was no food lost, and great rejoicing when the power returned. Food that is thawing is in a transition state where the temperature stays constant. As long as the meat is not fully thawed it is still at 32F. The problem with repeated semi-thawing is that the meat fibre break down, and ruin the texture of the meat. For hot dogs, sausage, and ground beef that doesn't matter. But whole cuts will get ruined if frozen solid repeatedly. μηδείς (talk) 02:41, 6 February 2016 (UTC) μηδείς (talk) 02:41, 6 February 2016 (UTC)

I know the OP's question concerned food in a freezer but I wanted to point out meat isn't some sort of simple liquid melting. In something like meat, conduction can be slow and I don't think radiation or convection are significant factors for heat transfer to the internal. So you can get a temperature diffential, you shouldn't expect all the meat to be at 32 F just because the middle isn't thawed. That's partly the reason many sources recommend against thawing at room temperature, the other key one is probably that people may leave the food out too long after thawing (well these are related); and the third is that people may thaw it somewhere they later use for prepration of food that won't be cooked or otherwise risk cross-contamination.

This source [4] suggests the actual difference when thawing is at 70 F (~21.1C) is fairly low, the surface temperature reaches 53 F (~11.7 C) which while in the danger zone it doesn't have to be held there for that long before the middle is thawed to be a concern. But reading it carefully suggests it would be useful to check the source which I think is an old issue of [5] which I couldn't find until I realise they had a copy [6] (I thought this was just a link to the earlier article). It seems they also tested thawing at 84F (~28.9 C) and surface temperatures there reached 63 F with the largest turkey (65 F with the smallest), and these were a concern particularly for the largest size since it took longer than the theoretical lowest 4 G time to thaw. [7] is possibly also of interest although I couldn't find read it given the age and rarity.

Interesting enough, having read that and [8] it seems that thawing in the fridge can actually result in more Pseudomonas spoilage bacteria given the longer times. Not at levels to cause safety concerns but which may negatively effect quality. Also it seems like wrapping with sufficient newspaper (or whatever) can significantly reduce the temperature differential.

The take away message would be that you definitely shouldn't assume your food was all at at 0 degrees C just because it wasn't completely thawed if it's meat or something else with poor heat transfer but that it probably isn't as a big a concern as most general sources [9] [10] [11] [12] make it out to be provide you don't leave it too long. The complicating factor if it's a big cut of meat (or a whole bird of poultry) which you don't want to cut, is how you know whether it is thawed completely. Probably partly the reason why it's often only recommend in industrial sectors where they can monitor room temperatures, times and carry out tests to determine precisely how long.

Also these all remind me how contradictory and poorly supported a lot of food safety advice tends to be. Although I know one of the reasons is because food safety agencies want simple rules of thumb people can follow like [13].

I'm pretty sure concerns over improper thawing are also partly the origin of the never re-freeze myth. (In fact two or all three of the sources provided by Sjö mention that you should only re-freeze if thawed in the refrigerator.) Even if the levels of growth aren't enough to be a concern if the food is properly cooked, if you keep doing thawing it that way eventually you're going to get concerning levels. The others concerns with re-freezing would be quality loss and people not probably accounting for time whatever the temperature. E.g. a small cut of raw meat which should often only be stored in the fridge for 6 days and may be completely thawed within a day or less in the fridge. So if it's left for 4 days then frozen then thawed and left another 4 days in the fridge then refrozen then thawed and left another 4 days before cooking, it's now probably been at least 9 days.

Nil Einne (talk) 05:15, 6 February 2016 (UTC)

Thanks, Nil Einne. When I was referring to meat as thawing, I meant that it still had solidly frozen meat detectable under the surface, and frost on the outside. I was happy to take the opportunity of that squall to explain why I had about 10 gallons of frozen water jugs in the freezer to my mother--mostly to retain the coolth--who complained they were unaesthetic. Luckfully my dad was a trained pipefitter. μηδείς (talk) 01:17, 9 February 2016 (UTC)

Thanks. Yes, I have neighbors/relatives who live downstairs. So I placed all my stuff there for the time being. Thanks. Joseph A. Spadaro (talk) 04:46, 6 February 2016 (UTC)

You, lucky, lucky bastard! 03:12, 7 February 2016 (UTC)

Thanks, all. Joseph A. Spadaro (talk) 19:07, 8 February 2016 (UTC)

Crane Collapses in Lower Manhattan, Killing at Least One Person

• htt p://www.nytimes. com/2016/02/06/nyregion/crane-collapse-lower-manhattan.html

At least one person was killed on Friday morning when a crane collapsed in Lower Manhattan, the police said.

The crane came down shortly before 8:30 a.m., toppling onto Worth Street and spanning more than the entire length of a city block, officials and witnesses said.

If you see the video taken by some office Workers shortly before the collapse, you hear very strange violin-like noise made by the fallen crane. What made the weird noise? Bending metal? Vibrating cables? -- Toytoy (talk) 17:13, 5 February 2016 (UTC)

The only weird sound I hear is the sound of a saw (or similar power tool). Is that what you mean? Sławomir
Biały 17:39, 5 February 2016 (UTC)

Here's the link. I suspect the cable was rubbing the framework due to the stress of the crane failing, I'll ask around. μηδείς (talk) 22:39, 5 February 2016 (UTC)

Sounds like shearing metal to me. It's an unfamiliar sound because we don't often hear that much metal shear at once. StuRat (talk) 23:33, 5 February 2016 (UTC)

Yes, I played this for my father (a retired engineer) and he said he had seen crane and tower collapses, but they did not make this noise. He suggested either a cable rubbing the framework or a broken strut rubbing the framework could have caused such a resonance. To me the noise sounds sweet, not like the tearing shriek of Godzilla, so I am going with resonance in a cable. μηδείς (talk) 01:05, 6 February 2016 (UTC)

Each collapse will be different. There isn't necessarily shearing metal in all collapses, either. In some cases, the crane just falls over. StuRat (talk) 15:30, 6 February 2016 (UTC)

To my ears the noise sounds like it is coming from inside the room with the people talking/partying. (Something to do with the echoes inside the room and high/low band pass filtering, though I can't say exactly what, gives me that impression) Can someone confirm it actually was produced from outside the window? I'd just expect it to sound ... different from out there. Wnt (talk) 02:47, 6 February 2016 (UTC)

If the sound is coming from outside, my guess is it's a warning hooter sounded by the crane when stability limits were exceeded. Akld guy (talk) 02:53, 6 February 2016 (UTC)

I go with Wnt. That noise is way too loud to be coming from the crane at that distance through ?double glazed windows. Even when the crane hits the ground there is an almost imperceptible thud, compared with outdoor witnesses who described it as 'like a bomb going off'. The other thing that requires explanation is the very similar repetition of the noise 3 or 4 times while the crane is in different positions. Unless a clip taken from outside the building turns up likely we'll never know. But it's nice for everyone to have a guess. Richard Avery (talk) 08:10, 6 February 2016 (UTC)

One commentator of the video (reply to leandro5455) says:

To all those wondering about the beeping or loud sound in the beginning... That is the sound of the truss structure of the crane failing and creating vibrations throughout the entire 500' length. If you look close you can see the sound increase and decrease with the speed of the end of the boom. This is also why the sound stops once the end really gets moving. I'm sure the sound was extremely loud on the other side of the insulated pane glass office windows. These things are unbelievably strong and only fail in extreme circumstances. As of right now it looks like the cause was wind. In short it was the death cries of the crane warning people to pay attention and get out of the way.

One factor against the sound originating from the crane, beyond the loudness, is that I can't find any descriptions in stories about the collapse of the noise (they mention the sounds at it crashed etc). Another thing you can learn from reading the comments is that the video was taken by construction workers (confirmed by [14]) and the building they were in was under the construction, so the possibility it was a power tool of some sort inside may not be unlikely as it would seem. (There seems to be a window where they're looking out so I presume the building was already fully enclosed.)

Also from reading stories of the collapse it seems the crane was being lowered at the time, so there's also the possibility it was some sort of warning siren.

Nil Einne (talk) 13:05, 6 February 2016 (UTC)

I don't think a power tool would be nearly that loud. Also, it wouldn't turn on by itself. StuRat (talk) 15:19, 6 February 2016 (UTC)

"turn on by itself"? Nil Einne (talk) 15:25, 6 February 2016 (UTC)

Oh, I see I misread that bit. I thought the power tool was supposedly on the falling crane, but now I see you meant it to be in the building. StuRat (talk) 15:27, 6 February 2016 (UTC)

Yes, the issue mentioned by others before I replied was that it was quite loud compared to other sounds relating to the crane (which I agree with) so perhaps it's inside the building. Under normal circumstances it'll be fairly uncommon for the to be a power tool inside a building but since these were construction workers and the building was probably under construction (or at least there were renovations going on) the possibly of a power tool inside the building is a lot more likely. Nil Einne (talk) 15:31, 6 February 2016 (UTC)

At around 1:05 in the video, you can see that this was a mobile crane, on catapillar tracks, and that it simply tipped over. It doesn't look like it broke with some loud tearing of metal or anything because the tracks are flipped upside-down, implying that the entire machine toppled as one more or less rigid structure. That seems unlikely to have happened if something major simply snapped close to the base and that the sound was tortured metal. Once it started to fall, most of it was simply under free-fall in gravity - so there would be less stresses on the structure at that point.

So I'm with the idea that this was some kind of a warning siren or an unrelated power tool inside the building. Unfortunately, the sound cuts off before there is enough movement in the crane to make for an obvious doppler-shift in the audio, so it's not easy to tell whether the noise came from the jib structure or from the base of the crane.

The thing that kinda suggests that the power tool hypothesis is good is that it cuts off around about the time that the guy holding the camera starts yelling about what's going on - which is probably when the guy with the power tool would have shut it off to come and look. It's hard to imagine why a warning siren would cut off at all. SteveBaker (talk) 16:18, 6 February 2016 (UTC)

Yeah, I don't think the sound has anything to do with the crane. Sounds like an angle grinder or similar to me (sander, buffer, etc.). Pitch is modulated as the power tool contact the surface at different pressures, then stops as you say, when the shouting starts. SemanticMantis (talk) 16:58, 6 February 2016 (UTC)

Is there any kind of open source software for analyzing echoes in sound? Listening to the recording I imagine there was a wall, oh maybe 20 feet behind the person speaking, and most of the voices and the "musical instrument" were clustered near but not outside the entrance from a hallway there. That's a lot of guessing though... I bet there are congenitally blind people who could do 10000% better at that kind of analysis. Still, is there something that can analyze sound and determine the timing of the echoes, correlate the L and R channels, to produce some kind of crude map? Then you might find a best fit for the "musical instrument" on the map. I bet the damned NSA has software like this that's good enough to practically make video of the inside of your house from your phone calls.... Wnt (talk) 00:18, 7 February 2016 (UTC)

Detection of echo(s) in recorded sound is a type of Autocorrelation analysis that finds the cross-correlation of the signal with itself at different time delays. It can be applied to estimate musical pitches and tempo; it was part of the attempted (inconclusive) analysis of the John F. Kennedy assassination Dictabelt recording, and I have used it to measure varying buffer delays on VoIP links. When the source sound is uncontrolled then accidental autocorrelations greatly confuse the analysis. Extracting directional autocorrelation from a stereo room recording would only be theoretically possible with long integration of fully controlled stimulus signals, such as Chirps used in compressive Sonar, and have front/back ambiguity. Even supposing demonic assistance, the intrusive domestic mapping project that Wnt wagers the National Security Agency can do would involve very noticeable disruption to telephones and get echo maps that are irretrievably scrambled by grating lobes (no article yet). AllBestFaith (talk) 16:10, 7 February 2016 (UTC)