Freezing Meats
How long can meat be safely frozen? What is freezer burn and how do I avoid it? How do I safe thaw meat? I'll discuss these questions and more in this article on freezing meats.
Freezing Duration
Frozen meats can be safely frozen indefinitely as long as your freezer maintains a temperature of 0°F or lower. At this temperature, bacteria, yeasts, and molds are inactive (not destroyed). Freezing meat simply stops the clock when microbes are concerned. So, if a piece of meat is about to go bad when you freeze it, it's about to go bad when after you thaw it. It's best to freeze fresh meat shortly after purchase unless you plan on using it.
Enzymes are not stopped by freezing, but merely slowed down, so the quality of the food may diminish over time. This is not a safety issue, but a food quality conern.
Freezer Burn
An avoidable quality detractor is freezer burn. Freezer burn occurs when air comes in contact with the surface of the food. Frozen water on the surface or just under the surface sublimates (like evaporation except going from solid directly to vapor) into the air. (This is the same reason why ice cubes slowly "disappear" in the freezer.) This causes moisture to be lost from the meat over time resulting in discoloration and a dry, leathery texture. The meat is still safe to eat, but the freezer burned sections won't taste good. Simply cut the affected portions off before or after cooking.
The risk of freezer burn can be minimized by good packaging. Although you can safely freeze meat in the packaging provided by the market, the plastic used are usually air permeable. Repacking the meat so that as little air as possible comes into direct contact with the food will reduce the chances of freezer burn. Some effective solutions are to pack the meat in liquid (like chicken parts in broth), vacuum sealing, wrapping in heavy-duty aluminum foil, or using a plastic freezer bag.
Packaging Meat For Freezing
Here's how I freeze inidividual pieces of meat:
First I place the a portion of meat onto a large piece of heavy-duty aluminum foil.
Fold two sides over so they meet in the center. Take the overlapping foil and fold in half to form a seal that runs along the package. Fold again in half in the same direction to form a double seal.
Flatten the open ends to form two flaps. If the flaps are long enough to overlap, fold them over the meat and fold the overlap in half to form a seal. Fold again to form a double seal (as shown below). If the flaps are not long enough to overlap, simply fold each flap in half and once again to seal the ends. The foil should fit tightly against the meat.
After all the meat has been wrapped, label a plastic freezer bag and place foil wrapped meat inside. Squeeze as much air as possible out of the bag and seal. Plastic bags that are not rated for freezing may be gas permeable and may result in freezer burn if frozen for longer than two months.
Wrapping the meat in aluminum foil first keeps portions separate, seals each piece of meat, and allows me to selectively thaw or refreeze portions. When freezing meat in liquid (for example, chicken pieces in broth), I just place the meat and liquid in a freezer bag and make sure that the meat is either in direct contact to the bag or covered by the liquid during freezing.
Thawing
There are a few safe methods of thawing meat, but only one way that allows you to refreeze the meat if you don't use it. Thawed meat inside the refrigerator is safe to be refrozen as long as the refrigerator maintains a temperature of 40°F or less.
1. Refrigerator - Takes a long time to thaw (one or two days for modest sized meats, 5 hours per pound for large meats like whole chicken or turkey). Results in an even thaw (same temperature throughout once it is done). Can be frozen after thawing.
2. Cold Water Bath - Place the meat in a leak proof bag and submerge in cold water until defrosted. Change the water every 30 minutes to an hour for the duration of the thaw. Cook the meat immediately. Do not refreeze.
3. Microwave Oven - Follow the directions provided with your microwave oven when defrosting. Meat usually comes out unevenly defrosted, so some parts may be warm (a prime breeding ground for microbes). Cook immediately. Do not refreeze.
38 Comments:
Great read.... this topic seems to have many old time wive's tales though. I recently saw a Chef from TBS "Dinner and a Movie" segment that made a point of saying meat in the freezer is not in suspended animation, but instead in a state of slow degradation.
I recently got an inexpensive aluminum grill/griddle (the kind that spans two burners on a stove), and was interested to see that it was also advertised as a great thawing device.
Indeed, a couple of weeks ago we thawed some rock-hard frozen swordfish on the thing in under an hour. I guess the conductive properties of the griddle radiate away cold very effectively.
Old wives' tales? The United States Department of Agriculture states "Food stored constantly at 0 °F will always be safe. Only the quality suffers with lengthy freezer storage. Freezing keeps food safe by slowing the movement of molecules, causing microbes to enter a dormant stage." Are you going to trust a chef on TV or an engineer who is obsessed with reading about cooking (or the government)? :) Hmmm, come to think of it, none of those are comforting sources of information. If you're concerned, then eat your frozen meats within six months - chances are the quality will be better anyway.
--
Joe,
That sounds like a great tip! I'll have to try it with my aluminum griddle or an aluminum pot. Did you thaw in the refrigerator?
On a side note...
As a bachelor that is both thrifty and enjoys the better things in life, yes it's possible, I have developed many ways to buy in bulk and eat well. One of which involves purchasing larger packages of skinless boneless chicken breast, and performing a combination seasoning / marinade while frozen. I too was at first a skeptic, but have found this to be an excellent way to not only preserve food but add delicious flavor as well. What I do is "clean up" the breast by cutting all remaning traces of fat and excess skin left by the packing plant. Then I puncture the breast lightly a few times with a common fork and season well with common spices and/or s&p. I then use one individual freezer safe ziplock bag, good quality bags work best I've found, per breast with a liberal amount of a good marindate. I usually create roughly 5 or 6 of these of various flavors and freeze them all. Waaalaaa, one grill mate for a party of one. Simply take a single bag out of the freezer on the way to work in the morning and place in the kitchen sink. When you get home you are ready to go for dinner. I'm not sure what the freezing action does, if anything, but they seem to be much juicer and hold the marinade much better when frozen together.
-itall
How about a cattle rancher and computer scientist? :)
You can store beef for well over a year with very little quality degradation, if you follow the steps in the post. Additionally, I'd reinforce some of the points by saying:
1) Buy yourself a deep freeze unit. Your refrigerator's freezer unit is not intended for storing food for long periods of time (think defrosting).
2) The tinfoil/ziploc method may work (I've never tried it). Personally, I use either butcher paper (available in big rolls, on the cheap) or a vacuum unit (FoodSavers are good and cheap at Costco and Amazon).
Also, do yourself a favor and save money by buying large cuts of meat, cutting them into steaks, and freezing them. You'd be surprised at how much cheaper it is to go buy a large cut at Costco or a butcher than it is to get lots of individual steaks at your grocer. You may also be able to save money by buying beef by the box (ask for boxed beef at your butcher shop [or Costco]).
-Andrew Wooster
I'm curious as to how effective it is to store fish (perhaps other meats also) for long duration in solid blocks of ice.
I had friends years ago in Montana who stored freshly caught trout in milk cartons filled with water. They swore by it and I did eat some that was over a year old that tasted quite excellent. It was a large commercial freezer that did provide low temp. Also the thaw time was not exactly quick, but I'm picky about my fish and this did seem to work well.
Thoughts?
re: thawing
This isn't specific to alumnium, it's a conductivity thing. You'll do even better with a cast iron pan immersed in another cast-iron pan. It's a matter of a) good thermal contact and b) low specific heat on the part of the thawing device. This is why air is such a terrible thawer: it conducts heat poorly and holds onto it fairly well.
The phone rang at the Butterball (turkey) customer support line. The person calling in asked, "How long will a turkey stay good frozen?" The help desk worker inquired how long that the person had had the turkey and was informed seventeen years. Well that is a long time and they had to ask some experts. Eventually the help desk worker said that they were finally able to conclude that if the turkey had been frozen at such and such a temperature the whole time it would be safe to eat but the flavor would probablly be off. The caller replied, "Thanky you so much, you have really helped me make my decision. We will donate this one to the church."
I thaw meat quickly on the metal surface of my kitchen stove.
itall said:
"Simply take a single bag out of the freezer on the way to work in the morning and place in the kitchen sink. When you get home you are ready to go for dinner."
Funny but I've been told this is a spectacularly good way of getting very sick. Your mileage may vary.
"Funny but I've been told this is a spectacularly good way of getting very sick. Your mileage may vary."
I don't think he was suggesting that you just eat the raw thawed bird. I think it was implied that you cook it when you get back.
"Funny but I've been told this is a spectacularly good way of getting very sick. Your mileage may vary."
"I don't think he was suggesting that you just eat the raw thawed bird. I think it was implied that you cook it when you get back."
Suppose it is thawed by 13:00, and you get home at 17:00. 4 hours of festering - mmmm.....
re: thawed in a sink
Since the chicken has probably finished thawing long before it's cooked, it better be cooked extremely thoroughly to ensure that all the potential samonella colonies have been completely destroyed. I wouldn't recommend one this thawing method - bring it down to fridge a day or two earlier.
I love the articles (and the charts are truly genius), but here's a small nit for the non-Francophones:
It is spelled "voila" (not "wala", not "waalaa"). It _is_ pronounced "vwaalaa", so everybody who has never seen it in print is excused for not knowing where to look for it in the dictionary (or la dictionare, for thaat matter). But now you've seen it, so no more excuses :-)
-A cooking & language geek.
Re the benefits of freezing. There are 3 components to food spoilage, (1)decomposition by micobials, (2) decomposition by chemistry (eg saponification), (3)decomposition by physical deterioration.
Freezing only prevents food degredation from spoilage due to microbial activity. Fats & oils will still become tainted with rancidity (#2) at -18C/0F ... eventually; and as a frozen strawberry (#3) will tell you there are some irreversible side effects to freezing.
I conduct research on rabbit pancreas we extract ribosomes (large molecules) from them. I found that if I store the pancreas (meat) at -20 deg Celius, I get freezer burn. But if I store the meat at -80 deg Celius, there is not freezer burn!
So for you geeks out there with available liquid Nitrogen this is a great way to keep meats for a LONG time.
The -20degC vs -80degC storage is valid, but here are a couple points:
1) The meat will freeze faster (probably almost instantly) when you dunk it in LN2 than in a (presumably an air chamber) -20C unit. Rapid freezing will result in a much more even freeze.
2) Presumably you put the stuff in a bag before freezing it either way. Dunking it in LN2 is going to force most of the air to one side of the bag and thus expose less surface area of the meat to the air, thus less area for the ice to sublimate.
3) The vapor pressure of water at -80degC is a LOT less than at -20degC or -5degC (approximately the temp of most consumer freezers) thus there will be less sublimation going on at the lower temperatures by default. This is the most beneficial thing about the low temp storage.
4) Rapidly freezing tissue will rupture the cells. Slow freezing does much less damage. I'm fairly sure that you don't just dunk it in LN2 to freeze it though -- usually putting things in low temp storage is a staged process -- ice bath or fridge, freezer, and then directly to cold storage or staged into to cold storage (depending on what chemicals other than water are in what you are storing). Anyway, I wouldn't advise dunking an expensive cut of meat into liquid nitrogen to preserve it. At least leave it in the freezer overnight first.
Re. Thawing in the Sink
I wouldn't thaw it in the sink, as sinks are full of nasty organisms, but thawing on the counter all day should be fine. A few hours sitting on the sideboard won't ruin the meat--remember that many meats are hung for a few days anyway. Besides, there just isn't enough time for toxins to accumulate, and cooking will kill off any micro-organisms.
As a last defense, one's immune system is pretty trustworthy:-)
Don't get all stressed out over thawed meat sitting at room temperature for a few hours. As George Carlin points out, your immune system needs germs to practice on. No antigens, no antibodies.
also the guy says to leave the meat in the ziplock bag when it thaws. i'm guessing if you cough on the meat or somehow horribly contaminate it before freezing, it's going to get festy pretty quick when it thaws, but if there's few contaminants to begin with it should be fine in the bag for a few hours. but where i live it's cold.
This is in response to the question about freezing fish. One thing to bear in mind when you freeze seafood is it has a much higher water content than most meats. Because of this there are really only two ways to effectively freeze fish and maintain most of its flavor and texture. Keep in mind that frozen fish will never be a match for fresh. To me it's like the difference between fresh tuna and its distant canned cousin. Personally I do not eat any frozen seafood unless I have no other option, but that is my own bit of snobbery.
The first freezing method is to do what your friend did, by placing the fish in direct contact with liquid and freezing the fish in a block of ice. This gentle method of freezing gives the best-tasting product and it is the only freezing method I recommend anyone use at home. You may have some limited success with plastic bags, foil or plastic wrap, but this method is pretty much guaranteed. The key is to make sure as much of the flesh as possible is surrounded by liquid.
The second method is called IQF, or Individually Quick Frozen, and is a commercial process that is often employed while fishing boats are at sea. I'm not sure of the particulars of the process, but the results speak for themselves. About 90% of the shrimp sold in the US is IQF, and it is also used for orange roughy, swordfish, halibut, sea bass, and a number of other species.
Hope that helps,
-- Charles (fishmonger turned software engineer)
Re. Thawing in the Sink
I wouldn't thaw it in the sink, as sinks are full of nasty organisms, but thawing on the counter all day should be fine. A few hours sitting on the sideboard won't ruin the meat--remember that many meats are hung for a few days anyway. Besides, there just isn't enough time for toxins to accumulate, and cooking will kill off any micro-organisms.
As a last defense, one's immune system is pretty trustworthy:-)
NOTE to all...I don't remove the meat from the freezer bag. It remains in the bag until cooking time, and yes for the smartass .. COOK the meat once thawed.
On another side note to the fish question. I am a very avvid fiserman and use the same method mentioned earlier. I freeze my cleaned fish fillets in large bags of water. I have kept and ate catfish over a year old using this method and there is no degredation in taste, etc.
AND .. you are very correct sir...VOILA! Thanks for pointing that out. =)
Re: thawing with the griddle: I guess out of habit I put it on the stove top -- i didn't turn on the burners, of course.
I ended up putting the fish in the fridge for an hour or so after it finished thawing, since it was faster than I thought it would be.
[posting anonymously 'cause I can't log in for some reason]
First: holy mackerel! What a great way of encoding a recipe!
Regarding bacteria: sometimes the biggest problem isn't the bacteria themselves but the toxins they produce. The entry for STAPHYLOCOCCUS AUREUS at the Virginia Department of Agriculture and Consumer Services says "Cooking won't destroy staph poison". Odd...I thought you just needed a high enough temperature. More grim details available at eMedicine.
While you're at the first URL, take at look at the other entries: symptoms can appear as long as 30 days after consumption. On a related note, consumption of moldy foods can be quite dangerous, causing permanent damage.
There should be an extension to the adage "what doesn't kill me makes me stronger":
What kills me, kills me. Or my guests: ("it was...the salmon
mousse!"). Oh, and sometimes what doesn't kill me just
cripples me for life.
I'll admit the modified form doesn't roll off the tongue quite as nicely, and doesn't lend itself to bravado. :-)
<preach>
You can spend your whole life with bad habits and never encounter a problem. However, I keep remembering a line from Tom Clancy's "Without Remorse", about Kelly/Clark "observing all the safety rules that had been written in the blood of less careful men". It's up to everyone to decide where to draw their personal line of caution; mine has tended to be a bit too far towards the incautious end of the spectrum and I've been burned a few times.
</preach>
On a lighter note, the main reason to get a chest-style "deep freezer" is because you can store food safely for longer periods. That's because it won't undergo the freeze-thaw cycles which frost-free, in-fridge freezers use (as often as every six hours) to avoid frost build-up. Technology geeks can see more detail at How Stuff Works and Appliance411.
-klode
Re leaving the chicken in the sink...
I do believe that the meat had been a) marinated and b) had spices added to it. Correct me if I am wrong but these additions do retard the growth of all of the nasty bugs everyone is freaking out about. Ever hear of cooked jerky? So properly seasoned before hand and marinated to boot before freezing sounds great to me. This is going to be a must try for me.
Man you guys sound like a bunch of old women. A marinated and seasoned piece of chicken properly stored in a freezer bag sitting thawed for a couple of hours. Now correct me if I am wrong but jerky has never seen any type of cooking device, so the spices keep the growth of bacteria to a minimum. Or kill them altogether and before somebody asks, no I have never seen chicken jerky, but the principle should still apply nicely. As for thawing my aluminum sink is killer. Thanks Michael for the awesome website being a single guy its really easy to start getting bored with your own cooking and need to freshen things up. And I do love to cook!
Listen Gentlemen
Bacteria only exists on the outside of the meat.
So it can be washed off after you have finished defrosting.
For a good example of this, smell a piece of defrosted fish, then wash it, then smell again.
You will be amazed.
re: bunch of old women
There are many similarities between the classic stereotype of an old woman and the minds of people predisposed to be engineers such as (1) we both believe what we believe, (2) we're both stubborn, and (3) we both have no problem saying what we believe. The difference is, even though an engineer might not immediately admit they are wrong, they will file away the discenting opinion in the backs of their mind as data and even possibly check it the next time they, let's say, encounter a turkey.
re: jerky
All the jerky I've known are dehydrated in an oven like contraption (an oven, a hot smoker, etc.). The dehydration serves as much to preserve the meat as the "spices". Most spices do little to extend the lifespan of a piece of meat, but salt and chile powders are effective (especially salt). In the case of the chicken on the counter for a couple hours to thaw, that's probably fine - but if it's a whole chicken or even large breasts, it's not just going to be two or three hours. The problem is that the exterior of the chicken thaws and rises above 40°F while the inside is frozen. While waiting the couple hours for the inside to thaw, the bacteria is rapidly multiplying. Now you've got a bag potentially full of salmonella juices seasoned with secret herbs and spices that's sure to get a little bit on something else in the kitchen that's not being fully cooked. Not too big of a problem for most young people and others who have a strong constitution - maybe a mild bout of diarrhea and you're done. But for others, it can become a serious problem and even life threatening. (Very concerning if you cooking for others; guests should not go home and develop a tummy ache or worse.)
re: Washing meats
I don't know what mr. ham pie meant when he said washing meats - I imagine he's only rinsing. That helps clear away much of the by products of microbes, but rarely does rinsing remove a substantial amount of surface organisms. Soap and water and scrubbing can knock down the bacteria count by a few orders of magnitude, but that's not an option for meats. (I do recommend soapy water and scrubbing fruits & vegetables when you can because slicing into a fruit (with knives or teeth) with surface contamination will bring the bad stuff into the flesh.) Because it's difficult to clean the outside of meat, I recommend at least searing the outside to kill anything clinging on if you plan on severing anything raw (sashimi, carpaccio). If you don't like the sear, trim it off after you sear it. Does everyone have to follow all these precautions? Probably not, but if you're really risk adverse, then follow the safety tips we've outlined. Do I follow all of them? Usually, but there are times when I do a little risk taking (but not when I have guests).
Now, the question I have for you all is this:
I have some t-bone steak with freezer burn (overnight - who would have thought?). Now, with freezer burn being as much about dehydration as, say for instance, jerky - would I be able to turn my steak into a jerky product that would be a) safe, and b) worth eating.....any ideas?
re: overnight freezer burn
I'm really surprised that the meat was able to dehydrate that quickly in just one night. Often, a color change in the meat is mistaken for freezer burn, but the color change does not affect texture or taste. Make sure the meat is burned but feeling it's surface texture after it has been thawed (in the refrigerator). If it's dry and coarse, then it is indeed freezer burn. If it's feels like the reast of the steak, then cook yourself a steak!
For jerky - I've never made jerky from freezer burned meat, but it seems like it could be worth a try. If the meat's been properly handled, there should be no safety issues with working with a freezer burned steak. I'm not sure if the burned area will take on the flavors of the marinade effectively, but it sounds like it'll be worth a try.
Re: Overnight freezer burn
It has discolouration, large cracks, and appears dry in its still frozen state. To say it was overnight was a bit of a hyperbole - it was most of the day and one night with no covering whatsoever. But it did get me thinking about my freezer-burn jerky theory.
I'm looking for a thawing machine in the market but couldn't find one.
Thawing meat in the microwave is the worst method I know because some part of the meat might get cooked and the rest are still frozen.
My husband is an electrical engineer and he doesn't cook at all. Unfortunately, it is my fault since I spoil him by taking care of all the meals.
I am going to send him your site and see if he can learn a thing or two and maybe suprise me with a meal.
my question is why is it that you can not re freeze meat thats been half or fully thawed? and can it get you sick/what will result from this
re: freezing thawed meats
Meats that have been thawed or partially thawed in the refrigerator can be refrozen. Meats that have thawed in the sink, microwave, or some other method (not recommended) should not be refrozen. Here's why:
When you thaw meat in the refrigerator, no part of the meat even reaches a temperature above 40°F, the low point of the temperature range where bacteria and microbial reproduction occurs at an appreciable level. This means, freshly thawed meat will have similar levels of microorganisms as the frozen meat - refreezing will result in roughly the same concentration of microbes.
When meat is thawed in another manner, parts of the meat will have reached a temperature above 40°F while other parts are still thawing. By the time the interior has fully thawed, the warmer portions have been conducive to microbial reproduction for quite some time. To refreeze the meat at this point will result in a larger culture of bacteria and microbes being frozen with the meat. When it is thawed again, the bacterial colonies have had a jump start and may reach concentrations high enough to cause us problems if not completely killed. Unfortunately, that usually requires us to hold the meat at a high temperature rendering it unpalatable (imagine cooking a steak to 170°F and holding it there for ten to fifteen minutes - that's going to be one tough piece of meat) to avoid food poisoning. If not careful, unwelcome visits to the bathroom may occur or even in some cases the body will forcibly reject the food. In the elderly or those with weak immune systems, extreme illness or even death may occur from the food poisoning.
Maybe not as important as the potential health issues when re-freezing thawed foods, there is also a food quality issue.
Ice crystals form when food freezes (when anything freezes for that matter). These crystals rupture cells. Repeating the freezing cycle damages more cells, which causes loss of moisture and texture.
Also, much earlier in this thread, someone stated that rapid freezing causes more cell damage than slow freezing. IIRC, Alton Brown demonstrated the opposite in the "Strawwberry Skies" episode of "Good Eats" - the strawberries he froze using dry ice oozed less juice than those frozen conventionally. His explanation was that rapid freezing results in the formation of smaller ice crystals than a slow freeze.
Great website, BTW. I just found this site yesterday and I've already read almost everything here.
I just returned from the hospital where I was treated for anaphyletic shock and poisoning (simultaneously!) due to scombroid poisoning of fresh salmon.
Neither freezing nor cooking kills this bacterial toxin. One can't see, smell or taste it. I think it is found mostly in warm water fish but more and more it is found in cold water fish like salmon. I think that this might be due to the environmentally friendly new "long-line" fishing (where fishing lines are miles long and it takes days to reel in the fish.) With ocean temperatures up a few degrees, there may be more of an opportunity for bad pathogens to develop?
Scombroid toxin can also form in cheese (especially swiss) and other foods. There's a quickie summary from New Zealand of scombroid poisoning at http://www.nzfsa.govt.nz/science/data-sheets/scombroid-poisoning.pdf
Even though it took a 911 call to save my life, I'm not going to stop eating fresh salmon. It's quite rare. I just thought I'd mention it here so people might be reminded to double check the source of their fresh fish.
Wonderful site, by the way. I just stumbled on y'all!
~Robin
I have come up with a good solution to the thawing/germs issue. I buy my chicken breast by the family pack, although it is only my husband and me. I cook all of it the first day; than I cut up some, shred some, some of it stays whole. THEN I freeze it. IT is so easy to pull out a bag of precooked chicken breast, throw it in the fridge then when we come home -- it's ready to go!
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