Begin by washing your tomatoes to remove any debris.
Dry the tomatoes well.
Remove the stem and core.
Remove any bruises, insect holes, or bad spots.
Slice, dice, or blend the tomatoes and place onto a freeze dryer tray that fits inside of your machine. Do not overfill the trays. Only fill them in a single layer diced or sliced, and no more than half full of tomato sauce.
Prefreeze the tray of tomatoes for at least 24 hours.
Place all of the trays into the freeze dryer and follow the instructions on the screen.
When the process is complete and before defrosting your machine, make sure the tomatoes are dried all the way. Feel them to make sure that no moisture remains and none of them are gummy.
When the process is complete, defrost your freeze dryer or open the door and let it defrost naturally.
Remove the trays and place the food into short or long term storage.