Ground meat has a shelf life of perhaps a few hours at room temperature. Lyophilization is then probably the only possible method to extend the shelf life to months, maybe even years (depending on the design and type of meat). After all, shelf life is the main issue here, because the weight loss is not that great. In fact, the yield from each batch is all the greater.
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
It is a good idea to grind the meat finely. If some parts of the meat are fatty, the coarse grinding may result in some of the 'strings' of meat being fat itself, which will not dry out. It is therefore necessary to grind and mix the fatty parts well so that the fat is spread out as much as possible.
Loading onto the shelf is relatively easy. The important thing is to cover the entire bottom of each of the five shelves that AMARU offers. The layer should not exceed 1 cm in thickness. We did not estimate the weight completely and in the end the whole load weighed 3.8 kg. Of course, AMARU could easily hold several kilograms more.
Freezing
With regard to the shelf-life of the processed meat, it is a good idea to get the meat onto the product trays as quickly as possible after grinding and start freezing. If you will be freezing in the AMARU, the "pre-seal" function will come in handy to ensure that the meat is not exposed to air while it freezes to the required temperature.
Thanks to the light weight of the load, we reached -30°C after just 9 hours, but for loads of around 5 - 6 kg I would recommend setting a freezing time of more like 12 hours.
Drying
As we noted in an earlier article, smaller pieces always freeze-dry better. Ground material is then clearly best for the speed of the drying process. Because of this and the relatively small amount of water in the meat, about 30 hours of drying was required.
Result
In terms of the original water content, the meat from previously freeze-dried foods is in a completely different category. As a result, we went from the original 3.8 kg to 1.45 kg by freeze-drying. This corresponds to about 37% of the original weight.
Visually, you can see the result for yourself in the video below:
Rehydration
Raw minced meat needs to be rehydrated in any case. I can't think of any use for it in dried form. The good news is that meat will always take back as much water as it needs and it goes fairly quickly. It's worth reiterating that freeze-drying is not sterilizing and even after drying it is still raw meat.
Uses
Weight reduction of about 60% is probably not the main reason for freeze-drying ground meat. This will instead be extended shelf life and the possibility of storage outside the fridge/freezer. Lyophilised minced meat can be easily rehydrated and used in spaghetti or burgers.