Jump to content

Wikipedia:Reference desk/Archives/Miscellaneous/2017 May 5

From Wikipedia, the free encyclopedia
Miscellaneous desk
< May 4 << Apr | May | Jun >> Current desk >
Welcome to the Wikipedia Miscellaneous Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


May 5

[edit]

frozen vegies

[edit]

can frozen vegies be thawed and frozen again — Preceding unsigned comment added by 49.187.157.3 (talk) 03:22, 5 May 2017 (UTC)[reply]

For veggies, generally yes, although it may affect the quality (sources: [1], [2], [3]). Some other foods should not be re-frozen (ice cream in particular is ruined if allowed to melt). Ian.thomson (talk) 04:15, 5 May 2017 (UTC)[reply]
Constantly thawing and refreezing veggies will tend to break down cell walls, resulting in mushier veggies. This isn't all bad, though, as some are too hard to begin with and this may be an improvement. Of course, cooking is the normal way to soften up such veggies. StuRat (talk) 05:23, 5 May 2017 (UTC)[reply]
Even ignoring food consistency, couldn't there be a risk of bacteria growth? ←Baseball Bugs What's up, Doc? carrots06:32, 5 May 2017 (UTC)[reply]
The usual guidance is thaw, cook, then refreeze. Wymspen (talk) 07:57, 5 May 2017 (UTC)[reply]
As I think (I haven't read them but they look like the sort of sources I've read before which deal with this sort of thing) Ian.thomson's source illustrate, this is the traditional guidance. But even some food safety authorities are now being more realistic. If the food can be used thawed, then there's generally no safety risk (as opposed to quality loss) in thawing and re-freezing provided you thaw the food safely (i.e. don't allow it to reach risky temperatures) and remember to consider total time. On the later point, since part of the food may thaw fairly quickly, the general advice is to take the time from the moment you start to thaw until at least an hour or two after putting it back into the freezer. In other words, if the food should be used within 3 days (for example) and it's thawed for a day, you need to remember you only have 2 days left next time you start to thaw. If you do this 4 times, then yes of course you may have problems. Vegetables can generally be kept thawed for longer than meat, but they also generally suffer greater quality change when thawed and refrozen (remembering they've often snap frozen in the first place). Nil Einne (talk) 12:32, 5 May 2017 (UTC)[reply]
I have some recent empirical evidence in the form of a pack of frozen peas which thawed and I then refroze on the grounds that the bacterial load was not likely to be that high. The quality change is marked: the peas are now frozen in a single solid block. Excuse me now, I need to go now and microwave the lot, some for my tea, others to make into a nice soup with a handful of sorrel from the garden. I don't have plans to refreeze peas again. Itsmejudith (talk) 17:31, 5 May 2017 (UTC)[reply]
Yes, that likely made them quite mushy. You might have better luck with veggies that are too hard to begin with, like large carrots. Also, separate and refreeze them in the proper-sized storage containers for your needs.
When you say you are going to use peas for your tea, that sounds like the New Zealand usage, where "tea" is the accompanying meal, not the drink. Aren't you British ? I didn't think they used it that way. StuRat (talk) 01:44, 6 May 2017 (UTC)[reply]
I wonder what happens if you put Tea (meal) into the search box? Oh, you read "Tea as a meal is associated with Britain, Ireland, and some Commonwealth countries." DuncanHill (talk) 02:19, 6 May 2017 (UTC)[reply]
That doesn't mean the usage is identical. For example, I don't believe "I'm going to eat tea now" has the same meaning in all cases. In NZ, tea strangely refers exclusively to the meal, and the drink is called a "cuppa". StuRat (talk) 03:40, 6 May 2017 (UTC)[reply]
Do you actually believe what you write? DuncanHill (talk) 04:01, 6 May 2017 (UTC)[reply]
[4]. StuRat (talk) 04:51, 6 May 2017 (UTC)[reply]
Don't confuse Dunkin by presenting facts. ←Baseball Bugs What's up, Doc? carrots05:03, 6 May 2017 (UTC)[reply]
In England we certainly (often) call the evening meal tea and we call a cuppa a cuppa. We don't say "I'm going to eat tea now". Itsmejudith (talk) 10:03, 6 May 2017 (UTC)[reply]
Does the sentence "Would you care for some tea ?" refer to the drink or the meal, when lacking any other context ? StuRat (talk) 21:20, 6 May 2017 (UTC)[reply]
Since you mentioned NZ usage, I'll respond. In NZ, the question wouldn't be asked in such an ambiguous way. One would ask, "Would you like a cup of tea?" or "Would you like to stay for tea?". Note that in NZ, this use of 'tea' to refer to the 6pm meal is disappearing and seems quaint in 2017, at least in Auckland where I live. "Dinner" would be by far the more usual term. NZ society is changing fast, with 72,000 immigrants coming in per year (c.f. NZ's population of 4.7 million), and more than 25% of the population of Auckland is Asian or Indian. These immigrants are having a big influence on traditional NZ values. Akld guy (talk) 20:33, 8 May 2017 (UTC)[reply]
None of the sources I linked to recommend cooking before refreezing at all:
  • Foodsafety.gov: Thawed or partially thawed food in the freezer may be safely refrozen if it still contains ice crystals or is at 40 °F or below. Partial thawing and refreezing may affect the quality of some food, but the food will be safe to eat with a further note of Discard after held above 40 °F for 6 hours for Home or commercially packaged or blanched vegetables.
  • USDA.gov: Once food is thawed in the refrigerator, it is safe to refreeze it without cooking, but Do not refreeze any foods left outside the refrigerator longer than 2 hours; 1 hour in temperatures above 90 °F.
  • NYTimes article: The notion that you cannot refreeze thawed foods “is a myth,” said Tina Hanes, a registered dietitian with the United States Department of Agriculture’s Food Safety and Inspection Service. Any raw or cooked food that has been thawed can be refrozen as long as it was thawed properly — in the refrigerator, not on the counter — and hasn’t spoiled. That includes raw meat, poultry, fish and seafood, Ms. Hanes said.
Those don't say "recook" at all, they say that it's perfectly safe to take a bag of frozen veggies (or a package of ground beef) out of the freezer, leave it in the fridge overnight, and then put it back in the freezer. thekitchn.com actually recommends not refreezing cooked proteins.
This is the reference desk, not the traditional guidance desk. Ian.thomson (talk) 00:17, 6 May 2017 (UTC)[reply]

Thanks for your quotes, they prove the sources largely say what I expected.

Perhaps I should clarify but I didn't mean the sources say you should only refreeze food when cooked, but rather they said the traditional guidance, including from food authorities, was that you should never refreeze thawed food unless cooked but that simply isn't true and in reality there's no safety harm from refreezing frozen food provided it was thawed properly and re-frozen before the food reaches when it should be used (and the thawed timed taken into account when thawed in the future. Your quotes illustrate they they do more or less say this. They don't really mention the time issue very well and aren't as clear on the traditional guidance, but otherwise they say what I expected.

Note while they don't explicitly mention the cook part (note, no one else mentioned re-cook), the last one strongly hints at it, saying the notion you cannot refreeze thawed food is a myth. This indicates there is a belief that thawed food cannot be refrozen. It doesn't explicitly mention that this notion was also spread by food safety authorities, but it's trivial to find some that still do [5] so it's a bit irrelevant.

As for cooking, properly thawed raw food designed to be used thawed clearly can be cooked, I don't think that is ever disputed. So either the myth is that if the food was ever frozen it gains some magical property that it can never be re-frozen. Or once cooked, it's just like any other cooked food whether using fresh or frozen products. Mostly the myth doesn't propose this magical property instead simply saying that raw food should be cooked after thawing rather than re-frozen. Hence the general traditional guidance is you need to cook the food if you want to (re)-freeze it, In fact one of the commentators in theKitchn explicitly mentioned this myth.

(Note the protein point was to do with refreezing already frozen cooked protein. It in fact encourages the freezing of cooked protein just after it's cooked. The point is unclear anyway, is it saying that cooked proteins should never be refrozen or perhaps referring to the fact that cooked proteins are often taken to have a relatively short shelf life so the freezing, thawing, refreezing, thawing cycle tends to be too long?)

P.S. IMO the fact that the traditional guidance/myth is out there and still spread even by food safety authorities is relevant to this question since it may help the OP understand why they need to take care with what they read. Yes we should make it clear this traditional guidance is a myth, as I think I did in my first post, but we shouldn't pretend it isn't out there. It doesn't of course help that this traditional guidance gets mixed up with the modern still common recommendation often from manufacturers not to re-freeze food once thawed which is not bad advice if it's for quality reasons. Unfortunately often they don't make this clear and just say don't re-freeze once thawed.

Critical thinking when reading sources, even with ones that seem to be RS, is always important, and it would be helpful for the OP to appreciate For example if the general advice is the food (whatever food) can be kept for 3 days thawed. Then how come if you thaw it in the fridge for 6 hours, then refreeze it and it's frozen with 6 hours, and then you thaw it again at some later stage and use it within 6 hours is this food potentially hazardous? Your earlier advice is the food is safe if you thaw and leave it in the fridge for 18 hours. Are you saying the cell wall breakage etc accelerates bacterial growth? Does the cycle activate some sort of spores of an organism that can grow even in freezing temperatures? Some other explanation? If there's no explanation, and there is generally none, then it should be obvious it's bad advice.

(As mentioned, theKithcn is one which actually is guilty of this with the protein advice in the sense that it could be good advice but it's not clear whether it's referring to safety or other issues. And if it is referring to safety issues, why it suggests so. Definitely if I have a small amount of cut up roast chicken, and it freezes in the freezer and thaws in the fridge within 1 hour, and I put it in the freezer just after cooking, then a few days later plan to use it so put it in the fridge for 2 hours, then change my mind so put it back in the freezer for a few days, then take it out again and use it within 2 hours, you'd need a very good explanation for why this raises safety concerns if there's no dispute the meat could be safely stored in the fridge for 24 hours after cooking before consumption or in the freezer for a month or longer.)

This critical thinking also helps with the reverse. The fact that authorities say food can be re-frozen once thawed doesn't mean they're saying for food that thaws fast and should be used within 3 days, it's okay to leave food in the fridge for 3 days then refreeze it then leave it in the fridge for another 3 days, then re-freeze it then leave it in the fridge another 3 days before using it. (One does mention the spoilt point although doesn't explain how you should consider it.)

Nil Einne (talk) 07:38, 6 May 2017 (UTC)[reply]

P.P.S. One final point, I should make clear you don't need an actual explaination if you have well supported evidence that re-freezing protein is harmful (or whatever). In that case the explanation is an interesting scientific question and hopefully we will eventually come up with a well supported theory for that after the necessary research etc. But then your source should be able to point to the peer reviewed articles where this evidence for harm was published. The problem is often there aren't any. Partly this reflects the fact food safety stuff can predate modern expectations etc. But this is still a problem, and if the evidence is either weak or non existant, this is when you should be strongly sceptical. Especially if there isn't even a decent explaination why this is believed or it goes against our current understanding. (A related example is the claim mobile phone or other wireless radiation is carcinogenic. Given there is very little evidence for this, and it also goes against our current understanding, there's good reason to be sceptical of any claims of harm.) Nil Einne (talk) 16:43, 7 May 2017 (UTC)[reply]
The question, to me, is "Why?" Just take what you need and put the rest back in the freezer. If vegetables are stuck together with ice, hit them with something to break them up. As discussed above, it's not an absolute no-no, but you need to take care to minimize the time food spends in the danger zone. --47.138.161.183 (talk) 07:19, 8 May 2017 (UTC)[reply]
The peas that I refroze were very, very solid. They could have been hit but that would have required some preparation, e.g. wrapping them in a clean bag then sandwiching between two chopping boards and thumping with the pressure cooker. In the end it was easier to thaw them all and cook them. Itsmejudith (talk) 10:33, 8 May 2017 (UTC)[reply]
So I concur with your conclusion: avoid doing it if you can. Itsmejudith (talk) 10:34, 8 May 2017 (UTC)[reply]