Would you recommend starsan as the number one for sterilisation? I have seen its very common for brewers to use.
Starsan doesn't sterilize, it
sanitizes, which is usually all we need to do for brewing, winemaking, etc.
Mind, we can only sanitize a surface that's already clean. IOW, you can't sanitize dirt.
Iodine (Povidone) based sanitizers are very good to use too. And arguably even better than Starsan in killing surface germs. But a working solution is only active for 24 hours (max).
A Starsan working solution can last for weeks, or month even. Many of us, homebrewers, can give testimony to that. That is, as long as the pH remains under 3.0, which is easy to check with a small piece of pH paper. See
*Note below.
I'm a stubborn Starsan user, clinging to the old (proven) method and storage, trusting my half-sized bucket with 3 gallons of working solution until
I'm getting grossed out by it.
Haven't encountered any issues yet, and there must me legions of users out there that haven't either.
Now, when I handle yeast, such as making starters, I use a
freshly made solution, no older than a week or so, as I've have always done, and successfully.
* Note:
At least, that's been the traditional knowledge on Starsan and its use for many, many years.
Until fairly recently... when the manufacturer changed their "recommendations." [
Link to their FAQ]
They now recommend not to use it after 1 hour (!). No explanation for that sudden and drastic change to be found, while the (reported) ingredients have remained the same.
Go figure...