There are two options when it comes to cooking frozen meat with sous vide:
If all this talk of freezing, cooling, thawing and slightly lower temperature sous vide cooking makes your head dizzy, just stick to the simplest sous vide cooking method:
With meat, there are serious health risks that can occur if you don't properly handle cooling and freezing. Food poisoning is a real danger and requires the necessary care, including with sous vide. How long the meat remains in certain temperature zones determines the risk. We recommend preparing meat with a core temperature of at least 55 degrees for cooling and freezing to minimize risks, but also to maintain the quality of your product. When freezing raw meat, you can set your water bath a few degrees higher for, for example, the first half of the cooking time so that it reaches the desired core temperature more quickly.
In order not to give bacteria, or at least insufficient, a chance to multiply too much, or to produce harmful quantities of toxins, you should preferably cool a piece of meat from the sous-vide bath with ice water to sufficiently low temperatures to be able to put it in the freezer. to lay.
Americans often talk about the “danger zone”: a certain range of temperatures that would be dangerous with meat. However, it is a combination of time and temperature, and in addition, the “danger zone” ends at 52 degrees instead of just the usually mentioned 60. To be sure, keep a core temperature of 55 degrees and cool your product in this way quickly in a bath with ice water or shock freezer.
However, a well-controlled sous-vide cooking process with adequate temperature and duration can kill all germs, allowing a safe shelf life of 2-4 weeks in the vacuum packaging (depending on fish, meat, vegetables, etc.). With sous-vide cooking, as well as many other cooking techniques, it is important to work carefully and hygienically. Food contamination problems are very real. So if you are not quite sure about this process, we recommend to follow the simple method which does not include a series of baking and freezing cycles before consuming the food.
The table opposite shows the combinations of time and temperature to reduce salmonella by 99.99999%. When determining the total cooking time you have to add the time that is needed to bring the core to the desired temperature and take into account that the heating times are usually given for a core temperature that is 1 degree lower (so if the sous vide is set to 57 degrees, then use the pasteurization time for 56 degrees).
The during are shown in hours (h), minutes (m) and seconds (s). Keep in mind that a reduction of 99.99999% is sufficient in a normal situation where you have handled the food normally. For example, if you first kept the food at 41 degrees for a long time (so that the salmonella grows to the maximum), 99.99999% may not be enough.
Furthermore, it is of course also important that the thermometer of your sous vide is properly calibrated and the temperature is kept constant. If you want to serve red steak to a pregnant woman and you are unsure about the temperature of your sous vide, it is best to be sure to take the time for 1 or 2 degrees lower.