Or do you want to know if the iodine crystals will not work if they are too old?
There should not be a problem with the iodine crystals aging.
As Arkady listened he found spoons in a desk drawer and looked for iodine crystals.
The hot-iodine method was supposed to employ iodine crystals over an alcohol burner in a glass box.
One little 1mm sized iodine crystal can tint a whole liter of water noticeably.
It is very simple to obtain iodine crystals.
If you let the alcohol evaporate the result will be iodine crystals deposited over the recipient walls.
I would suggest obtaining some iodine crystals and putting them in a sealed ampoule.
Care must be taken to prevent the small glass bottle of iodine crystals covered with water from freezing in cold climates.
I didn't have any trouble getting iodine crystals and ammonia.