Many of you write to us asking why we only freeze-dry the ingredients themselves and not the ready meals. So it is definitely worth experimenting a bit in the area of so-called outdoor food or expedition food. For our first experiment we chose a goulash, which would sometimes also be translated as stew.
Note: This test was performed on an earlier model of the AMARU lyophilizer. We have made several improvements since then and today the capacity would be higher and the process faster.
Preparation
For the first ready meal we chose beef goulash. In 415 g tins, the preparation of the loading is really easy and it is an excellent test material. In the case of commercial food freeze-drying, it would of course be worthwhile to cook your own without the added unnecessities.
I only cut some of the larger pieces of meat a little more before loading them into the machine so that they didn't slow down the drying process unnecessarily.
Freezing
I have one more thing to confess, and that is the miscalculation of the number of cans. This resulted in a total load of 8.3 kg instead of the planned 6.5 kg. Fortunately I realised this before I left and so set the freezing time to 15 hours. We have discussed how it is possible that we loaded more than the stated capacity into the AMAR in the article How to determine the capacity of a food freeze dryer (see below linked articles).
The required minimum temperature was finally reached in about 14 hours. The stew was, of course, at room temperature when the cooling started.
Drying
Considering the larger weight of the load, we were under no illusions of a quick process, as suggested by the slightly longer freezing time. According to the data we track on our test AMARU, the process took 39 hours to reach the final stage.
Result
I approached the lyophilizer with a bit of suspicion. I myself estimated that it would take at least 45 - 48 hours to dry almost 8.5 kg of stew. However, I was in for a surprise when I opened it. The stew was completely dry and showed it with large cracks across the brine layer as well as peeling off the side walls of the product trays. This is always a sign of a high degree of dryness. I wouldn't be afraid to try removing the stew 1-2 hours earlier next time.
After drying, we weighed the stew again and the weight was exactly 1.3 kg. This means that the freeze-drying brings the goulash to just over 15.5% of its original weight.
Rehydration
There is probably no point in mentioning that the goulash needs to be rehydrated, and probably no one will want to eat it dry. Regular readers of our articles will have guessed that here it is a matter of minutes to bring the freeze-dried stew back to its original state.
Usage
This is probably obvious. Ready meals like just goulash have their place in various expeditions and expeditions where weight or shelf life plays a big role in the food. It is enough to add an adequate amount of hot water to such dried stew and it is ready for consumption.