why would you not just buy the large bottles of the Real Lemon brand lemon juice. I think they have a long shelf life........Just curious.......I bet fresh lemon juice would taste much better but I am not sure its worth the effort.
Last fall I had extra lemons from canning and put them in a brine in the fridge. Still taste great - just wash off the salty water. I understand that is how sailors would prevent scurvy - lemons packed in barrels of salt water.
lemon juice can be canned like any other acidic fruit. You don't need to vacuum can it but it will take up a lot of space. If you dry it (try setting a half glass of juice in your frost free freezer until it is reduced to a couple of table spoons) then you can store a lot more of it in less room. You can dry it to a crystal powder and store it in plastic containers.
A note of caution- A north polar expedition in the 1800's took cans of commercially-bought concentrated lemon (or lime?) juice along with them to prevent scurvy, and although they took regular sips of it, they still got scurvy! It turned out the factory process had accidentally destroyed the Vit C content.
I'm not a nutrition expert so i'd research things fully on the net before I tried messing about with stuff.
Freeze drying (in a frost free refridgerator) will retain all the vitamins. Only the water is evaporated - like the way your ice cube tray dries out in the freezer over a couple of months. You do have to start with reall fruit juice and not the stuff from concentrate.
I've just found the relevant scurvy passage in the book 'Tales of Endurance' in an account of the British Royal Navy-sponsored George Nares Arctic expedition of 1876, these extracts are from pages 437 to 440-
"...scurvy...how this could have happened he did not understand.They had been taking regular sips from their bottles of lemon juice; by rights they should be perfectly healthy.....Nares's lemon juice had been issued in concentrated form, so that when it froze it did not crack the bottles in which it was stored.
The concentrating process involved boiling the juice in copper containers. Heat destroys vitamin C and copper leaches it."