First of all: good frozen meat should be almost odorless.Even meat in (slightly) spoiled condition should not really smell you. Check first if your freezer at least reaches-18 degrees Celsius. The specially designed fridge-thermometers that are available for this purpose generally give the actual temperature quite accurately and are relatively affordable. In fact, if your freezer is not cold enough, it may be that your frozen meat does not enter the freezer lightly, but it becomes correct.
I therefore assume that in your question you are referring to the fact that your minced beef smells like vinegar during freezing, or maybe just when defrosting.The answer is: that is not the intention. Minced meat just hears to smell fresh flesh, point. How Fresh Meat smells? That is difficult to describe and more a matter of experience. The air of fresh meat is certainly not really unpleasant to mention.
If meat has smells like an air reminiscent of ammonia, acid/vinegar or the really pungent and some metallic smell of rotten meat, this is really the result of bacterial growth in the flesh.
That said: a lightly acidic or ammonia-like air to thawing meat does not necessarily mean that meat is actually “tainted”. Especially for ammonia money that it is naturally already in blood and muscles, and therefore also in meat.Freezing of meat leaves part of the cell walls/membranes of the cells in the flesh because the water in the cytoplasmen of the cells freezes and expands. In this process (the meat is still freezing), this moisture is driven to the outside of the flesh, where it eventually freezes. However, meat that is not preserved in the freezer dries out in the freezer, which ensures that the juices formed during freezing on the outside of the meat lose water and thus become concentrated.
So if the meat already contained in freezing some by-products of bacteria (bacteria produce by-products, as gases, acids and liquids when digesting their food, which explains smells that we often experience as unappetizing.), it shall contain the Freezer “thickened” vleessap on the outside of the meat there an extra high concentration of.Sometimes some slimy and bloody moisture that you often find on a plate where you have defrosted a piece of meat or chopped up is also an example of this moisture.
Because of the higher concentration of these substances in this moisture, a piece of meat that is frozen for freezing, or at or after thawing, can smell a bit unwell.Whether you want to consume the piece of meat in question now or not, I leave it to everyone. Yes, the air in question is the result of bacterial growth in the flesh. But on the other hand, this does not have to be a problem for consumption, especially when the meat in question is heated well and through and through.
One final point in this story is that this phenomenon seems surprisingly more common when minced meat comes from, also reputable, (keur) butchers than in “supermarket meats”.This is probably because, for example, the butcher in question will be more likely to process “those lightly discolored riblappen” from the showcase in the minced meat. This while for “minced meat from the supermarket” as a rule, just directly at the flesh processor only the fresh leftovers/trimmings and qualitatively less high-struck parts of the animal are used. I personally don’t have such trouble with it as a butcher does this. In any case, minced beef should be well and through and heated and the meat in question is still perfectly suitable for consumption. It is only dangerous if this type of meat is processed in non-heated products like fillet Americain. A good butcher will never venture there. In addition, we must realise that in the Western world we sometimes strike a little with the freshness of our food: there are even very many voices that the enormous increase in conditions such as allergies and autoimmune diseases are a result of our very high hygiene and Food safety requirements which, in particular in our youth, on immune system “does not get enough training.” Anyway, personally I rate all food, also that with expiry date, on odor, color and sometimes also taste. More often than not, the food in question is still well suited for consumption. Or, we may be more confident in our nose.
In summary, a slight smell of acid or ammonia from frozen or defrosted meat from the freezer is a result of bacterial growth in the meat, but this certainly does not necessarily mean that the meat in question is no longer suitable for consumption. One has to ask yourself if you still want to use this meat in cases where it is not heated by and through, as is often common with so-called “red meat” like steak and lamb, steak tartare and so on.
That doesn’t sound right, e.g. Ossewurst if it’s about to get bad it starts to taste sour, think it’s either a smell of your freezer or is not good anymore.