I have some specimens that I have to thaw out and I was just wondering, would you let them thaw in the plastic they are wrapped in or let them thaw in full air circulation outside of the plastic wrapping? What are the pros and cons of both methods of thawing?
~ Darrell
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it is all con...don't do it... take out and let air circulate and their are other methods...but don't thaw in plastic bag! don't!
I've been thawing animals in plastic bags for a long time! :o
Amy
http://www.AmysTaxidermy.com
....for the simple fact that being sealed in a bag,anything frozen will have a tendency to sweat. Sweat= moisture build up.Being trapped in plastic at room temp=Bacterial growth at a faster speed.Bacteria=slippage. It might not happen every time, but it is a risk.At the very least, open the bag allowing it to breath and giving the moisture an escape route.
Have a great day everyone,
Dave
I don't know where you all are from, but thawing something in plastic is a whole lot different than putting a fresh specimen in a plastic bag before it is cooled.
There is absolutely no reason why something cannot be thawed in a plastic bag. In fact, if you defrost the specimen inside a plastic bag then there is not as much condensation of water on the specimen. As long as you don't leave the specimen for much time after it has reached room temperature there is no problem.
I think you are confusing the reverse proceedure. You should not place a fresh specimen in a plastic bag until all the body heat has been removed. It can be placed in cloth bags or paper bags and the cooling isn't retarded.
There are advantages to cooling a specimen inside a plastic bag - the system is similar to using a refrigerator. Th USDA always recommends thawing a turkey for human consumption inside a refrigerator to reduce decomposition. The theory is that as the surface thaws, the temperature will only drop down to the temp of the refrigerator. But a 20 lb turkey spends close to a week at 38 degrees before it is thawed sufficently. By that time the surface would have cooled far too much - except since it is in a plastic bag the temperature on the surface doesn't reach 38 degrees until the center does.
Try this experiment. Place a turkey without a bag on it on the floor of your lab, and another inside a plastic bag. Put thermocouples in various places on the body and just see how long various pieces are at different temperature before the legs get flexible enough to skin easily. There is where you get bacterial action! The plastic bag acts as a refrigerator, and sometimes I use ice chests to thaw large birds.
that's been shot with BBs, and let it thaw in a platic bag, open or not...and you will end up with something looking like liver.
Take another shotup specimen, out of plastic to thaw and let him dribble all you what, on you lab floor. If duck had identifiable feather patterns to bigin with it will still have it, unlike former. It will not look like the decomposing, gut content of an orca.
But pehaps I'm bad luck prone, so go ahead...thaw in plastic...and good luck. I know I've been there, done that, and ain't going back...just yet...
I have never had any trouble thawing in the bag. I also thaw out my edible food in the wrapper with no ill effects. I agree with the taxidermologist on this one. But if it makes you feel more at ease thaw without the bag.
Todd B
I think it boils down to personal preference!
What works for many may not work for you...it's the same ol' story whether it's thawing in plastic or using dry preservative etc! Too many factors to figure out what's best for everyone.
I have thawed many skins and whole animals in the heavy plastic packaging I had them in while in the freezer! With NO problems! But quite some time ago, I switched to thawing skins etc. unwrapped form plastic and then double wrapped in burlap. Knock on wood, it's a good method for slow thawing without excessive condensation!
This works great for me, and it may not for you. But, I'm sure I'm not the only one using this method though!
When ever you have a major difference in temperature between the air and any object you will get condensation unless there is absolutely no moisture in the air. Take an item out of the bag and let the warm air hit that frozen body and you will develop condensation on the critter. Now take that same frozen critter out of your freezer and let the warm air hit the plastic bag and where do you think the condensation will be? If you find moisture on your critter it is because you developed the moisture during the freezing process or you failed to protect the escape of any fluids ( burp the bag, put a cotton ball in the throat, wrap badly wounded critters in a cotton cloth etc.) If properly prepared you will not have problems thawing them in plastic and in fact less for the reasons the taxidermoglist stated above.
ANYTIME you have moisture trapped inside like was discribed is a recipe for the chances of bacteria build up!I agree...I always like to lay a specimin in the freezer to chill it evenly before I roll it up,bag it and freeze. But, thats not what the subject was to be about.I prefer the moisture to be allowed to escape instead of allowing it to become trapped between the hair and skin at room temperature.
When "Sweating" a cape out in the fridge, why dont we stick it into a plastic bag and tie it closed tight?And thats at 34-35 degrees!
What happens when you put a bit to much water based hide paste on a minnikin during the mounting process? Whats causing that odor?
I dont know,think of me as ignorant as your opening sentance suggests, but I'll continue to open that bag!
Regards,
Dave
Dave
ANYTIME you have moisture trapped inside like was discribed is a recipe for the chances of bacteria build up!I agree...I always like to lay a specimin in the freezer to chill it evenly before I roll it up,bag it and freeze. But, thats not what the subject was to be about.I prefer the moisture to be allowed to escape instead of allowing it to become trapped between the hair and skin at room temperature.
When "Sweating" a cape out in the fridge, why dont we stick it into a plastic bag and tie it closed tight?And thats at 34-35 degrees!
What happens when you put a bit to much water based hide paste on a minnikin during the mounting process? Whats causing that odor?
I dont know,think of me as ignorant as your opening sentance suggests, but I'll continue to open that bag!
Regards,
Dave
Dave
.....that darn twitch. Didn't mean to double click!
Surely you can't believe that. Putting extra water in hide paste has nothing to do with the question posted. Likewise, sweating of a deer cape IS in a plastic bag, otherwise the moiture wouldn't evenly spread throughout the dried portions of the hide. Weather you tie the bag shut or have it loosely closed, you still have the moiture there.
The rational for a heavilly peppered duck is also a bit askew. If the duck was bloody then it should be washed in water before skinning, and feather patterns don't just up and disappear - sheesh.
If you look into your cookbook, it recommends that edible chicken be consumed within three to five days of purchasing. A twenty pound turkey thawed in a refrigerator loosly flopped on the floor will have the head thaw within a day, and the rest of the bird will take up to a week, especially with the feathers. By then, the head will have the potential of slipping. But, if in a plastic bag, the micro-environment will stay around freezing - 32-33 degrees - until the bird is properly thawed throughout. Very similar to an ice cube in a glass of water. The water temperature will remain at 32 degrees until the ice is thawed, then it will raise the temperature. But condensation on the glass occurs. Conversely, thawing water filled plastic container, the temperature will stay inside the plastic to 32 degrees until the entire container will be thawed, then rise. However, if you that a block of ice in the refrigerator, as the water excapes it will quickly reach 38 degrees, and bacterial growth is exponential as a result of temperature. In freezing conditions bacteria are still alive, and some species actually reproduce and grow, but in higher temperatures, even to 38 degrees, the growth increases exponentially. I worked for a time in Meat Science Research for the USDA.
Your average duck body already has about a Pint of water in it, and the conditions for bacterial growth is already there since the Moiture laden meat is in close juxtaposition to the skin. Thawing inside a plastic bag will 1). reduce bacterial growth 2). prevent condensation on the outside and 3). prevent extremities from reaching warmer temperatures before the main body.
If the specimen has been in the bag for so long that it has large quantities of water condenced inside the bag, then by all means, switch plastic bags just before thawing, but Never be afraid of thawing a specimen in a plastic bag. (Just don't place a fresh specimen in a closed container until it is cooled to room temperature or cooler. The plastic bag acts to form a minature warming room which can cause bacterial action - but that was not the question posed).
I thank those with common sense who agreed with me, but in the end, it is up to personal preference. If you wish to put your specimens at risk, then, by all means do so.
My point of concern was with trapped moisture for a length of time weather it be thawing, sweating or an excessive amounts of a water based hide paste,knowing that the 2 main conditions for excelled bacteria growth is moisture and temperature.
The "Heart" of your material was very convincing and really made all the sence in the world to me after thinking about it.I will definately change my way of thinking because of it and will take your advice and start thawing in a bag.Being tought a certain way and practicing it for all these years has not made me close minded and I've learned something valuable. Thank you!
BUT......your intro and Conclusion could use a bit of work!
Thanks again,
Dave
I have an unsophisticated if not sharp tongue at times and apologize if it looked like I was riding you. Many people actually believe everything someone tells them and I didn't want incorrect information (at least in my eyes) placed here for others to read. Always be skeptical.
The thrust of the discussion is only about thawing a specimen here, and as soon as it is workable, it should be skinned. Though many will say that they leave a bird for as long as a week in a refrigerator, I would never do that. To be on the safe side it is good to skin the extremities of large animals as they are thawing, then spread borax or salt to draw out moisture or otherwise retard bacterial growth.
Many people don't fully understand the implications of freezing and thawing. A fellow graduate student back twenty two years ago had a full lion hide which was starting to slip and figured to place it in a freezer to "stop decomposition in its' tracks". Never mind that all balled up it would take about 2-3 days to freeze to the center, all time where bacterial action continued. Then, since he did not constrict the skin into a smaller cardboard box, the hide froze rock-hard inside the freezer and took three days to extract. He would grab loose hair so much he should have made showshoes from the hide.
Thanks for the info TAX. It has been my thinking all along to thaw in the plastic. I usually take a bird out of the freeze, leave it in the plastic bag and place it in the frig for as many as 3-4 days before skinning and mounting. Never had any problems.
The reason for thawing a turkey in the fridge, its to stop bacteria from growing. This is even on some of the baking turkeys instructions.
Want to make it simple, look at the bacteria growth in a plastic bag after 8 hours and int eh fridge after 3 days, get that cheap assed microscope from Wally world.
While thawing in plastic may be ok in some of the northern climates, don't do it in the southern climates.