I have a pound of ground pork I wanted to use half of at a time. I accidentally tossed the entire package into the freezer like an idiot without thinking.
While I was considering options, I couldn’t help but remember reading somewhere that thawing then refreezing was bad, bad, BAD because you were introducing nasty pathogens into the food. But I can’t remember anything but that impression.
Am I wrong? Is it only under certain circumstances? And if so, what are they?
As long as it is properly cooked what would it matter? I do believe it is speaking about thawing to room temp and freezing repeatedly which could allow some decomp to occur.
I’ve done this with chicken numerous times. Thaw it, refreeze half. I’m still alive, but maybe I’ve just been lucky.
That rule was before microwaves. That package of ground beef would sit out for several hours, giving bacteria time to gain a foothold. Even then, the rule was that as long as the remainder had ice crystals, it was ok to refreeze.
If you defrost quickly, in the microwave, you’re golden.
Agreed as long as you cook it properly you’re fine. I would think the taste and texture might be effected by the re-thawing though.
Ground beef is one of the most dangerous substances regarding spoilage, though, because the big surface area makes infection with bacteria much more likely and possible than a hunk of beef or chicken the same weight.
The official laws and hygiene rules here are for example that you freshly prepare ground beef and then must it eat the same day. At the end of day, everything left is thrown out. Thoroughly cooking at this point won’t help, either, because cooking only kills the bacteria themselves, not the toxins they’ve already secreted into the meat.
The other aspect to not-refreezing besides the bacteria problem is consistency - ice crystals formed during freezing and then melting turn things to mush which doesn’t taste as good as before, doing it twice makes it worse.
i think there might be texture issues. the meat might be frozen rapidly at the processing plant. after it is thawed and you slowly refreeze it then that could change some of the meat texture. it also will depend on the meat type, its moisture and rewrapping when you refreeze.
You can cook the entire package when you first need it and refreeze the cooked meat. That will address both the pathogen and the taste/texture issues.
I actually cook ground beef and package it that way for freezing most of the time now. Most of the recipes I use ground beef for require me to brown it first before adding other ingredients so it’s a huge time saver. I brown a couple of kilo’s and then package it in 1lb (raw weight) packages. You can buy cheaper ground meat this way too because not only do you get a lot of fat out while cooking, a lot of the remaining fat adheres to the side of the bag when defrosting.
The texture issue is legitimate, but the OP is asking about the spoilage issue.
For years, the conventional wisdom was that thawing followed by refreezing (at least sometimes) enabled significant bacterial growth. Surely this phenomenon had been observed – I can’t see this notion being made up without any evidence. I remember reading years ago an explanation for it, which unfortunately I don’t recall the details of. I’m a little surprised that in a once-over-lightly Google check, I haven’t found much mention of this, much less an explanation. While microwave defrosting may have made it less likely, not everyone uses that method of thawing. I did find a mention of preventing it by quick freezing, but most people never had, and still don’t have, the equipment to achieve that.
So my question, expanding on the OP, is: Can thawing then refreezing indeed promote rapid bacterial growth? If so, how? If not, why was it commonly cautioned against in years past? [On edit:] Note that this was, as mentioned above, not something that thorough cooking would negate – a dangerous level of spoilage was (supposedly) already reached.
Many people mistakenly believe that freezing will stop bacterial growth.
This is however wrong. It only slows it (That’s why you can’t keep food indefintly in the freezer - the max. is 1 1/2 to 2 years).
When you thaw the food, esp. the normal slow way, the bacteria start multiplying. If you then refreeze it, the little buggers don’t die from that; they stay there.
So the second round of thawing starts with not a handful of bacteria, but with a few million, again going through the multiplying cycle … and you end with quite a lot of bacteria on the second batch.
Thank you, constanze. That makes sense.
Not necessarily true. There are toxins produces by bacteria (?) that aren’t killed by cooking. Not sure if that applies in this case, but properly cooking food is not a blanket safety measure.
The main concern is if you leave it out to thaw at room temperature, the surface of the meat can reach temperatures warm enough to allow microbial growth while the interior is still frozen. This is true of all meats, of course, but if you go through the process twice it increases the chance of bad things happening, as constanze said.
That said, my personal opinion as someone with a degree in microbiology is that concern over microbial contamination of meat is generally overblown in this country. Yes, it happens. Yes, there are occasional outbreaks. But the vast majority of the meat sold here is safe, and the vast majority of potential problems are solved by thorough cooking. Many of the guidelines we hear about are really designed for restaurants and the food service industry, where a small, rare screwup can potentially sicken hundreds or thousands of people. With that kind of risk, it makes sense to be extra stringent. No one wants to be the one to tell the general public that they’re probably be fine relaxing things a little bit, because then they’ll be liable, but really I think we can all stand to chill out a bit.
People are just too paranoid about food poisoning nowadays, especially since most healthy adults recover in a day or so.
The fiat against refreezing meat was solely because of texture issues. When you freeze something, ice crystals are formed in it, and as the thaws and refreezes, the crystals cause more and more damage. The result is the meat has an unappetizing texture. This was probably worse in the earlier days of freezing, where you didn’t had an automatic defroster to dry the air and reduce crystals, but it still occurs.
Bacteria aren’t an issue.
I’m fairly careful with meat and food in general, but there has been more than one occasion where I’ve forgotten cooked food out on the stove overnight, then eaten it the next day with no problems. I agree that restaurant level standards are not necessarily required for your home kitchen. I would say, though, that there are enough idiots out there that would take some relaxation of standards and really run with them. Now that I think about it, though, they’d only be hurting themselves, so what the hell? 
I was taught that you can freeze and thaw meat ONCE while it is raw, and ONCE MORE after it is cooked. I never bothered to ask if that was for safety reasons or for taste/texture reasons, but it’s kept me alive for a long time.
The issue is the total amount of time the meat is unfrozen, not whether that time is punctuated by episodes of freezing. But, as noted above, the amount of time a piece of meat unfrozen is going to vary throughout that piece if you do multiple freezings and defrostings.
Assuming we’re talking about safety, not taste.
The thing is that you have no guarantee - it can also go wrong badly, and result in a day of feeling like crap from food poisioning. Over at notmydesk (a temp writing funny articles about how life as a temp sucks) he says that because he’s low on money, his weekly gamble is eating the seafood buffet on Fridays at a certain restaurant. If it works, he gets food cheap - if he looses, he spends the day vomiting and having the trots (for fun both at the same time).
Not everybody likes to take that gamble; not everybody can afford to (even if healthy adults recover quickly that isn’t much help if a child, elderly or immuncompromised person lives in the same household); not everybody is that low on money that they need to take the gamble.
How about this solution:
Take a saw. Wash it. Cut the frozen block in half. Wrap one half tightly and put back in the freezer.
I’ve actually done this.
Does any of this apply to foods other than meat? How about vegetables? I’d think that would be more of a texture issue than a health issue . . . right?