My wort is ready to put in secondary fermenter. 1 oz of star San makes 5 gallons, can I use what I saved from last Saturday or do I need to make more?
You can use it. Good on you for keeping it around. Not sure how long that'll be good for but you're definitely ok for now.
Personally I would make new, unless you made it with distilled water? My starsan lasts about 30 min to an hour when made with tap water, then it is usually off the required effective ph.
Check pH if possible, I think starsan needs to be under 3.0 to be effective. If you don't have pH meter, make new. Star San can be kept for a month in sealed container, by always check pH on old solution.
IIRC, pH 3.0 is the cutoff the guy from Five Star (can't think of his name) quotes in one or more webcasts.
Damn I've been reusing batches of starsan (never checked the pH) for up to 5 days at a time with no ill effects for years (80+ batches of beer) now. Maybe I'll buy a lottery ticket today!
I keep a 32 oz spray bottle of StarSan/RO water on hand all the time in my bar/brewhouse. It lasts for months. In fact, one 32 oz bottle of solution will last two or three batches of beer, including santizing the post-boil equipment, carboys, kegs, etc. No need to soak anything - you only need to get it wet. Used this way, an 8 oz bottle of product will last years.
I'm reading about this PH of 3.0 or lower stuff, mikehartigan. Does RO water maintain a low PH? I need to read up more on water/ph stuff.
I do the same as @mikehartigan My understanding is it is the minerals in tap water that screwup starsan (i.e. the Ph increases too much). If you use RO water then you basically have water without minerals so no problems. I mix up a gallon at a time and fill the spray bottle when needed.
It will keep a long time (months) in soft water, which you probably have. Super hard Midwestern water is another story. In fact if I lived in some places, I'd check the pH of fresh made solution to make sure the recommended 1oz/5gal was adequate.
I don't know the tds reading, but I do know that my well water creates plenty of scale in the shower faucet!
I stand corrected; I assumed you were in the mostly good metamorphic terrain in north-central NJ... but those rocks are a mess, as they are here in VT. There is some horrible well water less than 5 miles from Hill Farmstead's magical liquor. Our own well water does generate a little scale but it's mostly silicates, which don't raise the pH much.
I too have reused star San for a few months. I have had this cross my mind before but decided to reuse. No problems to date. But after reading this thread I will probably become a worry wort and change it out.
If you have a reliable pH meter you can test it to make sure before dumping a batch of sanitizer. I had a batch last for about two months without a major pH swing that I dumped due to unwanted particles floating in it from storage. I have found that the cloudiness is often a result of dissolved calcium if your water is from a deep source like a well or spring and that the clarity is not a reliable gauge of usability. There are a few podcasts on the Brewing Network regarding sanitizers and cleaners. One in particular is an interview with Charlie Talley from 5-Star Chemicals: http://thebrewingnetwork.com/shows/...Session-03-19-06-Sanitation-w/-Charlie-Talley
I usually keep my bucket of star san from brew day around in the garage next to the kegerator and rinse off my tap plugs in it from time to time. Guess Ill start keeping some RO water around to have an extended life solution...
My understanding is that it will remain usable for several weeks if you use distilled water and keep it in a closed contained. That's usually what I do. Since I don't have a pH meter I usually toss it after about 4 weeks.
