Am just starting to brew more regularly again and question is I have half a bottle of Videne that's maybe 2 years old; is it still ok to use, does it lose it's antiseptic qualities over time?
should be ok i think, is there a date on the bottle??
However its not as good a sanitiser as starsan imho. videne is viable for a short period after mixing while starsan is persistent and you have no worries about expending the sanitiser before the job is complete.
dosing with a trigger spray bottle makes it go even further, even when mixed with 5l tesco ashbeck water to avoid cloudiness in the solution with our local water it still works out cheaper in the long run.
i switched 1/2 way thru a videne bottle with the intention of using up the videne first, - NAW the starsan is so much easier, no dbl checking the colour for viability, just a quick ph strip test to confirm a below 3 ph (which is redundant cos it always has been) before use and a bottle mixed up will last a number of brews before a new batch needs mixing up. Just lable the bottle as it looks like water