I mixed 5 gal of starsan about a month ago and stored it in a spare glass carboy and have kept it covered. I went to the pool supply store to buy pH test strips to see if its still below the 3 pH suggested elsewhere. The guy said I’d be fine with the ones I bought and I got them home and their range is like 6.2-7.5…even after asking the owner if they would detect down to 3pH.
Anyway, back on topic. I was wondering if you guys think this is still usable for sanitizing. I plan on bottling this weekend and want to avoid mixing up a whole entire batch cause I’m kinda frugal. Should I risk it or just be safe and mix up some new stuff?
Cheap. Understood. But I always keep a gallon mixed for gravity tests, etc. I have found that it works well for up to several months. As Nighthawk pointed out, pH is key.
As to cloudiness, my starsan is always cloudy the second I mix it up. Strangely enough, it turns crystal clear after a few days in an airlock. So I never pay attention to clear/cloudy. To satisfy cheapness, I swirl two gallons around in a five gallon fermentir, then put some leftovers in a spray bottle. I’ve never kept it longer than a month, but it isn’t really that expensive to start with.
It is not expensive, but if it isn’t sold where you live (as is my case) you learn to stretch it. If it was good a month ago when you sealed it up in that carboy, it should be good now. I’ve kept batches for up to three months without problems, until I start to see some precipitate then I mix up fresh. Strangely, I’ve never seen a batch get above pH 3.0.
I use the cheap Ph tests strips. When it’s not red, it’s dead. This system has worked for me for years and has saved me some $. Dude at NB said he used a fresh batch every time. Not only is that expensive, it’s probably not that great for the environment.
The real test of starsan is its ph. As long as its below 3 you’re fine. If you’re really cheap you can even freshen it up with more concentrate at that point. Cloudiness is due to minerals precipitating out of hard water, and it can be a sign that its time to replace but it doesn’t always mean that.
My water is soft enough that it never gets cloudy, and I used to check pH but my internal “its probably time to replace the starsan” meter always went off before the pH was ever too high. These days I don’t bother with the pH, and I reuse the same starsan for 2 or 3 batches typically. 1 month is no biggie.
Interestingly, I live in the city where the water isn’t as hard but mine clouds up a couple hours after mixing it. I mixed a new batch this weekend just to be safe. I’ll order some pH test strips on my next NB order.
