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    Exclamation How to make freezer slow freeze poultry



    Hi All

    This is a very important question from me. I don't want to start discussing why it's so important however I would be very grateful if people could take the time to help me solve it. I have been trying to solve this for months now however have thus far been unsuccessful.

    Basically I want to slow freeze some poultry and cause maximum ice crystal damage. Ice crystals in meat develop passed the freezing point -2.2c(for poultry) and up to -4c. Therefore I need the meat to spend enough time in this zone in order to do damage I need.

    In order to do this I understand one simply needs to slow freeze the item however I am having trouble getting the freezer to slow freeze in the fist place and am wondering if there is an easy way to do this.

    Firstly I am trying to accomplish this from home (currently using a domestic freezer) however domestic freezer temps start at -10c and below. The rate of freezing I have found is way to fast with domestic freezers so I haven't been able to acquire the results I want.
    I have done things like insulate the meat in a box with towel but didn't see evidence of excessive purge/ice crystal damage and am guessing the items froze quickly.
    I also left the door open in order to bring the temperature down however the temp fluctuates too much e.g. is still to low or sometimes too high e.g. sometimes goes to 0 so I am having difficulty controlling that.

    Anyway somebody recommended to me that I should freeze at -5c and just leave the item there for a few days. However I understand it is not as simple as that. Firstly, since I cannot even get my freezer to come to -5c so I cannot test it this easily.
    Secondly I understand it is not the temperature that determines the RATE of freezing but actually:

    a) cooler capacity
    b) product load

    Guys, please kindly answer the following question for me:

    1) Does 'cooler capacity' refer to how much food the freezer can freeze in a given amount of time i.e. engine capacity. Basically, when you buy a freezer and it says this freezer can freeze x kg of food in n hours, is that the cooler capacity? Therefore if you put in more then the capacity the freezer does more works so freezing rate is slower?

    2) Is product load the current load in the freezer? e.g. if you put in one item and rest of freezer is empty will it freeze fast?
    Also If the product load is already frozen then the rate of freezing will be even faster? If however a bunch of new unfrozen food has been put in the rate will be slower?

    3) Somebody told me that you can achieve slow freezing by either increasing the product load over the capacity or I believe the capacity over the product load, however the second point doesn't make sense. I can see why if you place a fresh unfrozen load this will decrease freezing rate if it exceeds the capacity, however if the capacity is increased surely it can freeze more at the normal rate? Not sure if I understood the statement correctly. Here is the specialists statement from a previous email can you please explain what he means, especially in the last sentence:

    "Temperature alone will assure it only if the capacity of the freezer is very high. If the load is high in a refrigerator situation, it will not be able to maintain the -5C. It can warm even to + tempeatures in order to cool down the product. The rate of freezing depends on the rate of heat removal and hence they are dependent on the cooler capacity and product load. By increasing one over the other you can make it depend either on the cooler capacity or product load."

    4) How important is temperature and why, technically speaking, would a high capacity low temperature freezer cause slow freezing?

    5) If I need a low temp freezer I could probably hire a laboratory freezer and set it to -5c however since its a lab freezer I'm guessing the rate of freezing maybe fast regardless of set temp?

    Anyway guys can you please answer the above questions and also advise me on what I should do step by step in order to solve this problem from home. Should I rent a lab freezer or should I get a bunch of fresh food then stuff it in the freezer etc? WHat do you think I should do in order to slow freeze meat and cause as much ice crystal damage as possible.

    Anticipating your reply. Hope you will be able to help. Thanks.



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    Re: How to make freezer slow freeze poultry

    The slowest way of freezing food it to keep it just below freezing point ie -1. This is irrespective of duty. . A good domestic fridge on it's lowest setting will normally freeze food over time. Try using a domestic fridge set on no/ 5 and see how long it takes to freeze a glass of water.Don't let the cabinet internal temp drop below -4 c throughout the freezing process in order to ensure the chicken within the range you describe. Of course once fully frozen you will need to transfer it to a proper freezer to below -18c if long term storage is required.
    Last edited by r.bartlett; 02-07-2013 at 01:36 PM.

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    Re: How to make freezer slow freeze poultry

    Ok,
    First experiment to slow freeze your meat, over load the freezer..

    If you as well as the meat put loads of room tempered water in then the water will act as a heat storage. Depending on what type of freezer you got you could either put a couple of buckets 1/3 full of water in or loads of filled ice-cube bags.
    The more water you put in the longer it will take for your freezer to reach setpoint.


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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by The Viking View Post
    Ok,
    First experiment to slow freeze your meat, over load the freezer..

    If you as well as the meat put loads of room tempered water in then the water will act as a heat storage. Depending on what type of freezer you got you could either put a couple of buckets 1/3 full of water in or loads of filled ice-cube bags.
    The more water you put in the longer it will take for your freezer to reach setpoint.

    This is far too hit and miss IMHO. Once the ice starts to freeze then the cabinet will pull down quicker and quicker. There is no control over -2c to -4 c temperature over the time needed to form the crystals which is the critical issue here.

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    Re: How to make freezer slow freeze poultry

    I'm assuming you are using a chest freezer with mechanical thermostat. I'd get a digital thermostat and set it to turn off around -3c and back on around -1c. I would wire it in series with the original thermostat which probably controls on evaporator temperature rather than air temperature.
    I would program the digital thermostat to have an anti cycle time around 10 minutes.
    The temperature probe would want to be in the air in the freezer and away from the walls of the freezer.

    Have done something similar with a domestic fridge so it would keep cheese at a suitable temperature.
    Mostly found in Oxfordshire, UK :)

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    Re: How to make freezer slow freeze poultry

    Insulate your meat. It will freeze very slowly or it will be spoiled before be frozen

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    Re: How to make freezer slow freeze poultry

    Hi Iceman31
    I assume by trying to get ice crystal damage you are trying to get some sort of meat tenderising? or increase the WHC of the meat to increase revenue.
    The problem with slow freezing is you will have a high product moisture loss. To reduce this, your meat is blast frozen to seal outer skin then slow frozen at your crystal formation temperature.

    Best would be to control refrigeration with a product probe (meat inserted) to maintain core temp at desired temp and utilise a close control setting on a controller.(or multiple depth probes)
    Domestic fridges are notoriously bad at maintaining close control around set point. The lack of air flow over product in a domestic fridge gives poor heat transfer rates. defrost design will destroy your aim with the product and increase drip.

    increasing heat load in a refrigerator would reduce cooling capacity but this is very hit and miss and you sound like you want to do a far more scientific experiment. I would rent/ build a freezer with product probes, wide fin spacing and a temp range of 0 to -45.
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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by hookster View Post
    Hi Iceman31
    I assume by trying to get ice crystal damage you are trying to get some sort of meat tenderising? or increase the WHC of the meat to increase revenue.
    The problem with slow freezing is you will have a high product moisture loss. To reduce this, your meat is blast frozen to seal outer skin then slow frozen at your crystal formation temperature.

    Best would be to control refrigeration with a product probe (meat inserted) to maintain core temp at desired temp and utilise a close control setting on a controller.(or multiple depth probes)
    Domestic fridges are notoriously bad at maintaining close control around set point. The lack of air flow over product in a domestic fridge gives poor heat transfer rates. defrost design will destroy your aim with the product and increase drip.

    increasing heat load in a refrigerator would reduce cooling capacity but this is very hit and miss and you sound like you want to do a far more scientific experiment. I would rent/ build a freezer with product probes, wide fin spacing and a temp range of 0 to -45.
    Thanks for these replies. I am not looking for meat tenderising and I do WANT MOISTURE LOSS. Actually the more moisture loss the better. However I do not want to do this using a meat dehydrator because not only do I want excessive moisture loss, I also WANT THE ICE CRYSTALS TO RUPTURE THE CELLS, something that can only be achieved using freezing.

    Why am I doing this? Well it's a long story and this is not a commercial project. Guys I really need to be able to do this. I am not a freezer engineer or anything like that, just a chronically ill guy who sits at home most of my days. I absolutely need to find out how to do this.

    Can you give any more suggestions? How much would it cost to build something like this and is it something I can rent?

    Anticipating your reply. Thanks

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    Re: How to make freezer slow freeze poultry

    Guys, I also notice nobody has answered the specific questions I asked. Please can somebody do that if possible.

    ALso I take it the suggestions are:
    1. Overload domestic freezer and hope for the best.
    2. Build/buy/rent a freezer which will fluctuate between -1 to -3.
    3. Use fridge compartment on lowest setting.

    I can try 1 but other say it will probably not work, do you think it is still worth trying?

    I have to research/find something that does 2.

    A low setting fridge compartment goes to -0 however the freezing point for chicken is -2.2c. Also the bigger ice crystals occur at -3 to -4 so I don't know if a fridge compartment can go that for.

    Also, even if we control the temperature, might the freezer not still freeze it fast and bring it up to the required temperature e.g. you put the chicken in and it could be within 3 hours it brings it to -4c which would be too quick?

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    Re: How to make freezer slow freeze poultry

    1. Won't work or work consistently. (you would have to keep unloading the cold excess stock and replacing it with warm so that the freezer never quite catches up)
    2. Depends on your budget, and if you know for sure the process will give you the results you want. (modifying you existing freezer (assuming its a basic mechanical stat model) would be cheaper and prove the concept imo)
    3. Could also work well, depends on the amount of product you are hoping to produce a day.

    What i'd do i think is get a small cheap table top freezer say 80, then make up a short lead and plug to a box with electronic thermostat in, then run a short lead from the box to a socket. Plug box in wall, plug freezer in socket, put temperature probe from box on freezer. Put chicken in freezer, i'd probably put some water in plastic bottles to increase the load and make the temperature more stable if you are not putting much chicken in.

    You could then set the temperature at say -1C for a few hours, then -2C etc etc on the electronic stat.

    Expect about 100/140 in parts to make a box and plug,socket.

    May work out easier to hire something if you can, this is not a everyday problem so am just giving it my best guess.
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    Re: How to make freezer slow freeze poultry

    Why am I doing this? Well it's a long story and this is not a commercial project. Guys I really need to be able to do this. I am not a freezer engineer or anything like that, just a chronically ill guy who sits at home most of my days. I absolutely need to find out how to do this.


    are u a serial killer???- i'm confused to the the ideas of destroying chickens- maybe a blender might help-

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by install monkey View Post
    Why am I doing this? Well it's a long story and this is not a commercial project. Guys I really need to be able to do this. I am not a freezer engineer or anything like that, just a chronically ill guy who sits at home most of my days. I absolutely need to find out how to do this.


    are u a serial killer???- i'm confused to the the ideas of destroying chickens- maybe a blender might help-
    No I'm not a serial killer or the like. I will tell you what this is about later but I don't want to make a long story now.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by monkey spanners View Post
    1. Won't work or work consistently. (you would have to keep unloading the cold excess stock and replacing it with warm so that the freezer never quite catches up)
    2. Depends on your budget, and if you know for sure the process will give you the results you want. (modifying you existing freezer (assuming its a basic mechanical stat model) would be cheaper and prove the concept imo)
    3. Could also work well, depends on the amount of product you are hoping to produce a day.

    What i'd do i think is get a small cheap table top freezer say 80, then make up a short lead and plug to a box with electronic thermostat in, then run a short lead from the box to a socket. Plug box in wall, plug freezer in socket, put temperature probe from box on freezer. Put chicken in freezer, i'd probably put some water in plastic bottles to increase the load and make the temperature more stable if you are not putting much chicken in.

    You could then set the temperature at say -1C for a few hours, then -2C etc etc on the electronic stat.

    Expect about 100/140 in parts to make a box and plug,socket.

    May work out easier to hire something if you can, this is not a everyday problem so am just giving it my best guess.
    There are some lab freezers which I believe you can set to -1 and below. Would it not be better to rent one of these instead of building one since I believe I can set the temperature on certain lab freezers.

    Also even if the lab freezer stays at high temperatures, this doesn't determine the rate of freezing right? For example if you set it to -4c, this is the FINAL equilibrium temp it will reach. As for how fast(rate) of freezing this is dependant on the cooler capacity and load am I correct? Guys this is why I asked all the questions so I can become clear about what is required. I may be wrong but I am guessing controlling the temp alone will not necessarily cause slow freezing.

    btw, how much would it cost to pay somebody to build me a small slow freezer as you have described?

    Thanks

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    Re: How to make freezer slow freeze poultry

    2. Depends on your budget, and if you know for sure the process will give you the results you want. (modifying you existing freezer (assuming its a basic mechanical stat model) would be cheaper and prove the concept imo)
    .
    Guys, If I asked a professional to come and modify my current freezer so that I could control the temperature how much would it cost roughly? Would any of you be willing to do it?

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    Re: How to make freezer slow freeze poultry

    Ok you probably won't as I notice most of you are far from London however, in any case, how much would it roughly cost for somebody to come and do it and where would I find such people? Thanks

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    Re: How to make freezer slow freeze poultry

    An idea occurred to me a few minutes ago.
    I have noticed red stains around the leg bones of fresh chickens before.
    I have been told that this was due to bring the temperature down to just freezing during transport, then thawing.
    If you want to simulate the ice crystals developing during a slow freeze you could try freezing, partial thawing, then refreezing. I believe this will cause the effect you are looking for.

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    Re: How to make freezer slow freeze poultry

    It is sounding very complicated for a process to ruin a chicken! just give it to my wife she can do it in 40 minutes

    As NH3LVR says you can program a partial thaw and increase drip from product to reduce moisture.
    80% of water can be frozen at the temperature range you are looking for but you will require a lot lower for connective moisture. Then there is increase in bacteria etc at lower freezing temperatures and variance with temperature.

    For botulism you will have to refer to my wife again!

    I would suggest vacuum cooling as it would be easy to control and dwell time the shortest. Of course this may be out of your budget range but if it is a project of love then a chest freezer could be converted.

    It may be worth you giving us your desired outcome description, to see if what you desire can be achieved?
    Last edited by hookster; 03-07-2013 at 06:50 AM.
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    Re: How to make freezer slow freeze poultry

    Follow the chicken processors method of injecting meat tissue with water and freezer as fast as possible, the water will tenderize the meat as it freezes and expands. Alternatively change the thermostat in domestic freezer for a higher control range. Slow freezing will risk bacteria growth in chicken in particular

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by iceman31 View Post
    Ok you probably won't as I notice most of you are far from London however, in any case, how much would it roughly cost for somebody to come and do it and where would I find such people? Thanks
    cheaper to buy one on ebay...

    http://www.ebay.co.uk/itm/All-purpos...item1c34488c60
    Last edited by r.bartlett; 03-07-2013 at 07:38 AM.

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    Re: How to make freezer slow freeze poultry

    You leave the freezer as normal, introduce a false load to control the temperture (PID controller, solid state relay and a small heater) I would add a circulation fan (for even temp), there is a good chance your SST will not raise massively, so you will still get your moisture loss. a couple of hundred quid should what you need.

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    Re: How to make freezer slow freeze poultry

    I think maybe you're just over estimating the damage slow freezing will do ?

    I make frozen dog food, and there's times when we've had freezer problems (break downs, high summer temperatures - the reasons I joined here)

    I've never noticed any loss of quality in the meat between freezing in a few hours and 24+hours

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    Re: How to make freezer slow freeze poultry

    Hi Knighty. No comparison between dog food and chicken production for human consumption. I cannot hover up a ten day old raw road kill and smile and survive and wag my tail. Food safety and bacto counts, salmonella etc., fresh raw chicken chilled has a limited shelf life of minimum hours, only if the process is in-line with health standards requirements

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by NH3LVR View Post
    An idea occurred to me a few minutes ago.
    I have noticed red stains around the leg bones of fresh chickens before.
    I have been told that this was due to bring the temperature down to just freezing during transport, then thawing.
    If you want to simulate the ice crystals developing during a slow freeze you could try freezing, partial thawing, then refreezing. I believe this will cause the effect you are looking for.
    This doesn't work because if the rate of freezing is fast with each freezer attempt, small crystals will grow in the same place. Unless the crystals are big to begin with and there is partial thaw refreeze however you need a slow freeze to begin with.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by Magoo View Post
    Follow the chicken processors method of injecting meat tissue with water and freezer as fast as possible, the water will tenderize the meat as it freezes and expands. Alternatively change the thermostat in domestic freezer for a higher control range. Slow freezing will risk bacteria growth in chicken in particular
    Water injection will put water into the chicken but not into the cells of the chicken. I need the ice crystal to rupture these cells so I need the water inside the cell. As such placing water surrounding the cells won't cause the cells to rupture so i'm guessing.

    Also provided the meat is below 0c I'm guessing bacteria will not develop since it's at higher temperatures that bacteria becomes a problem.

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    Re: How to make freezer slow freeze poultry

    I would put a small heater with an adjustable thermostat in the chest, giving you a constant, controllable load. After a few test freezes, you should be able to adjust the rate at which the meat freezes. That, to me, would be the easiest and most cost-effective way to get your results.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by danny_s_pike View Post
    I would put a small heater with an adjustable thermostat in the chest, giving you a constant, controllable load. After a few test freezes, you should be able to adjust the rate at which the meat freezes. That, to me, would be the easiest and most cost-effective way to get your results.
    Can you expand on how this works, What heaters would you use and how does this constant controllable load work with different amounts of product. What temperature would you expect the freezer to run at and why and how long are you expecting it to take and to what temperature are you goig to freeze the meet?
    what is your budget cost approx?

    thanks

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by Magoo View Post
    Hi Knighty. No comparison between dog food and chicken production for human consumption. I cannot hover up a ten day old raw road kill and smile and survive and wag my tail. Food safety and bacto counts, salmonella etc., fresh raw chicken chilled has a limited shelf life of minimum hours, only if the process is in-line with health standards requirements
    eh? no sure where you're coming from there... you've ignored what I said and started to talk about hygiene ?
    (also, right now, my government enforced product testing is stricter than for human grade food)

    my point was that I've seen all different meats, frozen at all different rates, and I've never experienced a big difference in quality (ignoring flash freezing of course)

    those freeze rates including times when we've had a break down and frozen meat very slowly, on mass (and then thrown it away)

    so I still think you're over estimating the amount of damage that will occur to the chicken, so you'll never be able to find what you're looking for, because it's not there to be found
    Last edited by knighty; 05-07-2013 at 02:25 AM.

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    Re: How to make freezer slow freeze poultry

    actually, I've re-read what you said

    you said "I WANT THE ICE CRYSTALS TO RUPTURE THE CELLS"


    but you have it backwards, when slow freezing ice crystals form outside of the cells, water leaves the cells, and the cells shrink

    you need to go to -60'C (ish) to rupture cells on mass


    there is a slight skin effect, where you can burst the cells on the surface of the meat if you fluctuate the storage temperature of the meat - as the surface defrosts moisture forums, when it refreezes the ice crystals are larget than previously

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    Re: How to make freezer slow freeze poultry

    why has no one mentioned thermal electric junctions? ie peltiers, control scheme is more complicated but between ebay and a few water cooling shops for pc's he'd have a very percise controle over capacity and temp.

    And I will restate, with out knowing what your final goal is we are all just pissing in the wind proverbialy

    What is it you are trying to achieve? from there we can make some hard conclusions in the process stream that needs to be designed!

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by The MG Pony View Post
    why has no one mentioned thermal electric junctions?
    I guess most of us live in the real world and know that peltier cooling is a waste of time and effort. I always get amazed at some of the applications suggested in this thread

    The idea he has interests us but to be honest what he is trying to achieve is a waste of time with a domestic set up although may be a nice tinker toy! I agree with you though MG Pony for this thread to progress we need expected outcome and maybe even an idea of the size and scale of product to be frozen.
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    Re: How to make freezer slow freeze poultry

    Best advise would be to consult your local Food Safety authority, for the handling and processing of chicken meat products. Before you do anything.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by hookster View Post
    I guess most of us live in the real world and know that peltier cooling is a waste of time and effort
    for any real application you'd be correct, how ever for a test bed to determine the best time and temp it would prove use full.

    a couple high powered moduals and a good pwm drive and a precision thermometer he'd have a very tun able freezing box.
    Now in Redvers Sask.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by r.bartlett View Post
    Can you expand on how this works, What heaters would you use and how does this constant controllable load work with different amounts of product. What temperature would you expect the freezer to run at and why and how long are you expecting it to take and to what temperature are you goig to freeze the meet?
    what is your budget cost approx?

    thanks
    First off, the man has a domestic freezer. He stated that his freezer will not allow him to slow freeze. His goal is to slow freeze. If you put a load in the freezer (ie a domestic, cheap heater), that will make the system work harder, decreasing the freezing capacity of the system. When his poultry is entered into the equation, the freezer must work to freeze the meat and fight the load of the heater at the same time, making freezing times longer.

    He did not mention in this thread that he wanted to introduce different amounts of product, so I cannot comment on that part. The temps are posted by the OP, so I will not reiterate.

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    Re: How to make freezer slow freeze poultry

    http://www.youtube.com/watch?v=WT_2P7WdKzw
    Put a VFD on that freezer and then you can have the PID controller first hold it just above freezing, then slowly drop it at your desired rate. (Set the existing thermostat as low as it goes or bypass it so it doesn't interfere.)

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by danny_s_pike View Post
    First off, the man has a domestic freezer. He stated that his freezer will not allow him to slow freeze. His goal is to slow freeze. If you put a load in the freezer (ie a domestic, cheap heater), that will make the system work harder, decreasing the freezing capacity of the system. When his poultry is entered into the equation, the freezer must work to freeze the meat and fight the load of the heater at the same time, making freezing times longer.

    He did not mention in this thread that he wanted to introduce different amounts of product, so I cannot comment on that part. The temps are posted by the OP, so I will not reiterate.
    how would your system act differently to an adjustable thermostat?

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by r.bartlett View Post
    how would your system act differently to an adjustable thermostat?
    More load=Longer freezing times


    NiHaoMike, your VFD idea is a great solution. I have a 350HP screw package that runs on a VFD. Instead of using its slide valve, the compressor will vary its speed. This dramatically reduces power consumption. If he wishes to build a system that will allow him to produce his poultry on a regular basis, this is a good solution IMO.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by danny_s_pike View Post
    More load=Longer freezing times


    .
    great so walk me through the process. What happens inside the freezer when an excess load is introduced?

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by r.bartlett View Post
    great so walk me through the process. What happens inside the freezer when an excess load is introduced?
    Really? ok, refrigerant is introduced into the evaporator in the freezer. This refrigerant would normally absorb the heat of the product and flash off, carrying with it the heat removed from the product. If excessive load were to be introduced, the refrigerant flowing through the evaporator must absorb more heat, up to the system's maximum design refrigeration capacity. In order to bring the temps down to the desired setpoint, the refrigerant will continue to absorb heat. If there is more load, there is more heat that must be transferred. The system can only work up to its capacity limits, so it will take longer to remove the heat in the freezer.

    In my own refrigeration plant, I can tell if a blast freezer has 10 racks of product or 40 racks, by looking at the length of time the system took to go through its freeze cycle.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by danny_s_pike View Post
    Really? ok, refrigerant is introduced into the evaporator in the freezer. This refrigerant would normally absorb the heat of the product and flash off, carrying with it the heat removed from the product. If excessive load were to be introduced, the refrigerant flowing through the evaporator must absorb more heat, up to the system's maximum design refrigeration capacity. In order to bring the temps down to the desired setpoint, the refrigerant will continue to absorb heat. If there is more load, there is more heat that must be transferred. The system can only work up to its capacity limits, so it will take longer to remove the heat in the freezer.

    In my own refrigeration plant, I can tell if a blast freezer has 10 racks of product or 40 racks, by looking at the length of time the system took to go through its freeze cycle.
    so if I understand you correctly the temperature rises inside the cabinet for an unknown time depending upon how long the system takes to get on top of the product load?

    if not please explain in better terms for me to understand

    but if so please explain the difference between your solution and raising the set point from -18 to -3 with a 20 dollar stat to simulate the same effect but with greater control of the target products final temperature which was one of the posters critical wants

    tia

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    Re: How to make freezer slow freeze poultry

    Is this a fridge /freezer. How about this ,take the feeler of the stat and put it in the freezer compartment.Most of these stats are clamped on the fridge coil so i would imagine their range would be -5 to 10c. Then just control the temp of the freezer compartment itself referencing off a thermometer.ps dont i dont work on domestics so could be wrong about the range

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by r.bartlett View Post
    so if I understand you correctly the temperature rises inside the cabinet for an unknown time depending upon how long the system takes to get on top of the product load?

    if not please explain in better terms for me to understand

    but if so please explain the difference between your solution and raising the set point from -18 to -3 with a 20 dollar stat to simulate the same effect but with greater control of the target products final temperature which was one of the posters critical wants
    Sorry about that. I don't mean to use the heater to raise the temperature in the freezer. The heater can be used to reduce the cooling capacity of the freezer, thus increasing freezing time. The poster states that he wishes for a slow freeze. I understand that a $20 stat would give you control of the requested temps, but as he stated:

    Also even if the lab freezer stays at high temperatures, this doesn't determine the rate of freezing right? For example if you set it to -4c, this is the FINAL equilibrium temp it will reach. As for how fast(rate) of freezing this is dependant on the cooler capacity and load am I correct? Guys this is why I asked all the questions so I can become clear about what is required. I may be wrong but I am guessing controlling the temp alone will not necessarily cause slow freezing.

    I just wished to add my .02c. I'm not saying that my idea is a great one and there are far better solutions, just thinking that a chronically ill guy who spends his time at home and who knows very little about refrigeration could try this idea out.

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    Re: How to make freezer slow freeze poultry

    I was about to say, if you can keep the temp difference between the chicken and the freezer low enough, you could slow freeze (or try to)


    but it's all pretty irreverent when no mater how slow he freezes it, it's not going to do what he wants anyway

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    Re: How to make freezer slow freeze poultry

    Fast freezing causes a uniform lattice type ice structure, expansion still occurs and may rupture the cell wall (a bit like a pipe freezing) Slow freezing cause the ice to build somewhat like a snow flake with many edges and points, with penetrates the cell wall in many places.
    on defrosting the cell wall become weaker/mis-shaped. The more tears the greater the deterioration.
    Unless you freeze dry, removing the internal cell moisture, which seems to make the cell wall more rigid.
    it is the deterioration of the cell walls that make frozen food mushy, compared to fresh.

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    Re: How to make freezer slow freeze poultry

    let some gas out soyou dont let it get below -5 plus without the full gas charge it would take a long time to get to temp

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    Angry Re: How to make freezer slow freeze poultry

    Quote Originally Posted by rjsinoz View Post
    let some gas out soyou dont let it get below -5 plus without the full gas charge it would take a long time to get to temp
    that is incredibly irresponsible and illegal, any refrigerant is to be recovered and handled properly! if that was don back in the R-12 days it wouldn't be banned as it is now. now days you still have idiots venting the stuff guaranteeing that ozone hole stays big n healthy!
    Now in Redvers Sask.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by The MG Pony View Post
    that is incredibly irresponsible and illegal, any refrigerant is to be recovered and handled properly! if that was don back in the R-12 days it wouldn't be banned as it is now. now days you still have idiots venting the stuff guaranteeing that ozone hole stays big n healthy!
    hey idiot i dont know how small ur reclaim unit is but mine would cycle off on lp if i tryed to recover the 200 grams in a small chest freezer so a few seconds of letting the gas go is the same as purging your gauge line 20 times, do u do that or are u so worried about the enviroment u just let air enter the system

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    Re: How to make freezer slow freeze poultry

    oh yeah all the ideas of buying this and installing that also are causing the hole to get bigger by adding a car on the road to get the parts and the manufacture to make more parts only to find out it doesnt work anyways just let 50grams out and ull be right

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    Re: How to make freezer slow freeze poultry

    I have a standered proper recovery unit, and it does a great job on 16 grams or less, it is not hard at all to properly recover a charge. not hard to make them either to code if you don't one small enough make it!!

    As for gauges? I use quality ones with anti-blow back valves, no air in system.

    I guess this is the difference between a skilled tech and a non skilled one? One buys the tools and uses them in a way that achieves his goal, rather then finding excuses and cop outs to not do there duties diligently?

    and all your excuses still comes down to it is illegal, and I'd report you in an instant had I have more info on you.
    Last edited by The MG Pony; 13-07-2013 at 05:53 PM.
    Now in Redvers Sask.

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by rjsinoz View Post
    hey idiot
    There is no need to take that kind of tone.
    Mostly found in Oxfordshire, UK :)

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    Re: How to make freezer slow freeze poultry

    Quote Originally Posted by The MG Pony View Post
    I have a standered proper recovery unit, and it does a great job on 16 grams or less, it is not hard at all to properly recover a charge. not hard to make them either to code if you don't one small enough make it!!

    As for gauges? I use quality ones with anti-blow back valves, no air in system.

    I guess this is the difference between a skilled tech and a non skilled one? One buys the tools and uses them in a way that achieves his goal, rather then finding excuses and cop outs to not do there duties diligently?

    and all your excuses still comes down to it is illegal, and I'd report you in an instant had I have more info on you.
    of course you would u sound like a snitch, as for the correct tools i have a cps Recovery Unit which does 10.4 Kg/Hr Vapour its 1 HP and Oil Less cost $3000 AU
    thats 174gram a minute so thats 43.5 grams every 25 seconds now considering i would purge the unit due to the large supermarket racks i work on either have co2/r134a or r404a in them, (i would assume the chest freezer has r12 in it maybe r134a) a complete purge of the recovery unit would be required anyways, its internal volume capacity would be about 30-50grams so lets say i lose 15 grams to a purge to ensure no cross contaimination occurs i am fairly confident the unit will cycle off on LP pretty quickly as my compressors efficiency (which does get checked regularly) is correct.
    perhaps you should check the piece of crap unit you have and see if its still pumping correctly, unless of course you work on household fridges and only need a slow recovery unit.or of course u dont know how to check it.
    as for my gauges i have digital fieldpiece gauges type SMAN4 Digital Manifold 4-Valve which cost $700 AU i also have anti-blow back valves or inline ball valves on mine but due to the ever changing world we live in i am constantly working on different systems with different refrigerants.ie the charge has to come out if there isnt a unit with that gas located near by. then u must purge the line.
    maybe you work on one type of unit with the same gas all the time but i am constantly being sent to different systems to service and repair them no install work just breakdowns.
    if you think you are so skilled go to this forum and lets here your answer
    http://www.refrigeration-engineer.co...PROVE-ME-WRONG

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