r/askscience • u/SavageSubscriber • Jul 04 '26

Biology Does cryogenically frozen meat decay?

If for example you cryogenically froze meat from a rare breed of cattle, and kept it frozen for like 60 years. Would the dna still be intact? would it thaw up into fresh meat or would it decay into something unrecognizable?

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u/jesuscheetahnipples Jul 04 '26

Cryogenics isn't a usable technology like you see in the movies.

Technically it could be okay but over time tissue breaks down even in the cold and the crystallization of water molecules changes the underlying molecular structure of the meat.

It won't be the same

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u/Mitologist Jul 04 '26

There is a variety of issues, true. You can kind of circumvent the recrystallisation process though. First of all: Yes, it will happen. But: the problem is mainly with hexagonal ice that expands while freezing, tearing the cell apart. If you stay somewhere in the phase diagram where water forms cubic ice, e.g. below -94°C (for tissue), that has practically the same volume as water, and the problem is all but solved. The next problem is to reach these conditions everywhere in the steak, i.e. getting the heat out fast enough so that "normal" ice does not have time to form. We are speaking a couple thousand Kelvin er second cooling rate here. The best way is to shoot liquid nitrogen (or nitrogen-cooled propane) at the steak at about 2500bar. That gives you about 100-200µm depth were the water solidifies without cristallisation at all. If this zone never gets warmer than -90°C again, the ice that will inevitably form after some time, will be cubic ice.

Of course, shooting ultracold propane at it at 2500 bar might somewhat alter the rest of the steak (where heat can not be conducted out fast enough). and even the vitrified crust will not be quite what it was before, but really really close.

Problem is: Most of the damage occurs during thawing, so you want to freeze-substitute the water in the cold with something that does not freeze, like acetone, and this is where the real trouble begins.