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Carnivorous / Zero Carb Approach / Dangers of thawing and refreezing
« on: March 04, 2009, 03:40:49 pm »
In various places, I have read the same two health warnings about thawing meats:
1. The first is that you should always thaw meat in the fridge, never at room temperature.
2. The second is that you should only thaw raw meat once, so you should never put raw meat that has been thawed back into the freezer. (This even means the time in between buying frozen meat and placing it in the fridge should be short enough that the meat does not thaw in transit.)
One reason given was that both thawing slowly in the fridge, and thawing only once, retains the meat juices better, making the meat less dry, more tasty and more nutritious.
But I only want to focus on the second reason, which is that bacteria have less chance of proliferating. Outside of the fridge the proliferation of micro-organisms occurs extremely quickly. When you thaw large pieces of meat in the open air, it is possible that the outside of the meat is already at room temperature, while the inside is still frozen.
And when freezing meat a second time, the meat has to be frozen quickly. If the inside of the meat does not freeze quickly enough, micro-organism can keep multiplying in the core until all the meat eventually freezes. When thawing again, this increased biomass can grow larger once more. That is why freezing must happen extremely quickly, and must occur at a temperature of at most -24 °C (-11 °F), which is a temperature lower than what most freezers can handle, -18 °C (0 °F).
Now on this forum the dangers of micro-organisms are generally downplayed. Still, I would like to eat my meat with as little proliferation of micro-organisms as possible. I am not yet convinced by the benefits of "high meat". Also, in paleolithic times the entire animal would normally be eaten almost immediately after it was hunted. Even if raw meat was eaten after several days in the paleolithic era, after freezing the cellular structure of meat is completely damaged by the expanding ice crystals, so decay of frozen raw meat should happen much faster than fresh raw meat.
What are your thoughts?
I would prefer scientific arguments over anecdotal evidence ("I eat refrozen meat all the time and nothing bad ever happened"), but if the latter is all you have that would also be useful.
(This issue is very relevant at the moment: I only have access to frozen grass-fed beef, and from one company only. They package muscle meats in small portions, but I just ordered organs. Because delivering organs is unusual for them, they want to vacuum-seal the organs as a whole, as they said it was easier for them. But a lot of organs such as liver are huge, and way too much for me to eat in a few days. This would mean I would have to refreeze the organs again, something of which I doubt the safety. I will try to arrange if thet can deliver smaller portions, but would like to hear your thoughts.)
1. The first is that you should always thaw meat in the fridge, never at room temperature.
2. The second is that you should only thaw raw meat once, so you should never put raw meat that has been thawed back into the freezer. (This even means the time in between buying frozen meat and placing it in the fridge should be short enough that the meat does not thaw in transit.)
One reason given was that both thawing slowly in the fridge, and thawing only once, retains the meat juices better, making the meat less dry, more tasty and more nutritious.
But I only want to focus on the second reason, which is that bacteria have less chance of proliferating. Outside of the fridge the proliferation of micro-organisms occurs extremely quickly. When you thaw large pieces of meat in the open air, it is possible that the outside of the meat is already at room temperature, while the inside is still frozen.
And when freezing meat a second time, the meat has to be frozen quickly. If the inside of the meat does not freeze quickly enough, micro-organism can keep multiplying in the core until all the meat eventually freezes. When thawing again, this increased biomass can grow larger once more. That is why freezing must happen extremely quickly, and must occur at a temperature of at most -24 °C (-11 °F), which is a temperature lower than what most freezers can handle, -18 °C (0 °F).
Now on this forum the dangers of micro-organisms are generally downplayed. Still, I would like to eat my meat with as little proliferation of micro-organisms as possible. I am not yet convinced by the benefits of "high meat". Also, in paleolithic times the entire animal would normally be eaten almost immediately after it was hunted. Even if raw meat was eaten after several days in the paleolithic era, after freezing the cellular structure of meat is completely damaged by the expanding ice crystals, so decay of frozen raw meat should happen much faster than fresh raw meat.
What are your thoughts?
I would prefer scientific arguments over anecdotal evidence ("I eat refrozen meat all the time and nothing bad ever happened"), but if the latter is all you have that would also be useful.
(This issue is very relevant at the moment: I only have access to frozen grass-fed beef, and from one company only. They package muscle meats in small portions, but I just ordered organs. Because delivering organs is unusual for them, they want to vacuum-seal the organs as a whole, as they said it was easier for them. But a lot of organs such as liver are huge, and way too much for me to eat in a few days. This would mean I would have to refreeze the organs again, something of which I doubt the safety. I will try to arrange if thet can deliver smaller portions, but would like to hear your thoughts.)
and because I feel there is a lot of expertise on this forum.
) The book then mostly collected dust on the shelf.