I’ve always been interested in making my own freeze-dried food for camping or emergencies, and I’ve also been interested in the process in general. I picked up a small vapor trap capable of reaching -50C on eBay and a small vacuum pump off Craigslist. I don’t have any machine tools but I managed to drill and tap a 4″ disc of aluminum with a cordless drill and some tenacity. Despite NOT being designed for this, the vapor trap actually seals pretty well against the metal bucket inside (normally they use a glass jar) and reaches an absolute vacuum of about 30 microns.
