Sauces and casseroles can both be vacuum packed. There are three reasons why you may want to do this.

To retain flavour and consistency of sauces. The absence of air and the consequent lack of oxidation mean that sauces will keep their flavour better than if they were stored in the fridge without being vacuum packed. They can then be reheated by being placed in a pan of hot water. Unlike reheating the sauce in a pan, no water is lost in evaporation and the sauce will retain its consistency. If you are working in a commercial kitchen then you can reheat several different sauces in the same pan of hot water which saves space on the stove as well as the need to wash multiple pans.

To reheat casseroles while maintaining texture. Reheating casseroles in a vacuum pouch avoids the problem of drying out because there is no water lost in evaporation. In addition, the heat is applied from all sides so that you don’t need to stir the casserole during reheating. This prevents any cooked meat and vegetables from breaking up and means that the reheated food looks as good as it did when it was first made.

Making larger quantities saves time and money. It makes a lot of sense economically to make sauces and casseroles in larger quantities. This is because the time and effort involved in purchasing the ingredients, preparing them and cleaning up afterwards is not greatly affected by the amount made. It is also usually cheaper to buy ingredients in larger quantities than in smaller ones.

Having made a casserole or sauce, you will need to chill it before vacuum packing it. This is done to make it more viscous (thicker) and to prevent any liquid from being drawn into the machine. Decide what sized bags to use based on portion sizes. The table below shows the optimum bag size for different numbers of portions

Having chilled the sauce or casserole down to about 4 degrees Celsius, you should turn down the top 5cms of the bags. This prevents the top portion of the bag from coming into contact with the food which can prevent a good heat seal from being made. If you are bagging a lot of food then it is worth obtaining some lengths of plastic tubing about six inches long and between 4 and 6 inches in diameter. The end of the plastic tubing can be placed in the vacuum pouch to hold it open and it can be used as a sort of funnel. This makes filling the bags single-handed much easier and ensures that you don’t get any food on the top part of the vacuum pouch.

It may be a good idea to raise the vacuum packing machine a few inches up off the work surface so that the vacuum pouches can be kept more upright. This, plus the chilling, should prevent any liquid from being drawn into the vacuum packing machine during the packing process. You should also remember that you do not need a very powerful vacuum inside the bag. The main reason for removing the air is to prevent the bag from bursting when the contents are reheated. If you have a variable pressure machine then you could pack at a lower pressure (for example 0.1 Bar) or if you have a manual machine you could press the sealing switch as soon as it looks as though most of the air has been drawn out of the vacuum pouch.

When you come to reheat the sauce or casserole, place the vacuum pouch in a large pan of very hot but not boiling water. Do not puncture the vacuum pouch, if you have removed the air then it will not burst when reheated. You will need to make sure that the contents are thoroughly reheated before serving.