StarSan with Distilled Water

How long will this keep in a standard cleaned bucket or spray bottle? I've read various opinions on the matter. Right now I have a bucket filled with 5 gallons of distilled water that I use whenever I need to sanitize something as well as two spray bottles filled with the same. How long should I expect to be able to keep this before needing to dump it and put fresh distilled water and sanitizer in it?

Star San is effective as long as the pH is below 3. From what I understand its life time is largely dependent on the amount of soils you have on your equipment when you sanitize it. If you're following good cleaning practices then it should last quite a while... I think heard a podcast from the creator who claimed "weeks to months" when using distilled water. I don't personally keep my starsan around long (keep a few spray bottles that are refilled every brew day) but if I did I would use some pH strips to know when I needed to dump and mix up a fresh batch. That is cheaper than losing a whole batch due to improper sanitation.

In distilled or RO water, Star San should be stable indefinitely. I've routinely used mixed SS in a jug that's stayed in the basement overwinter with no ill effects.

I don't understand the gain of mixing with distilled water and reusing. I can get a 32 oz bottle from my local supply shop for about $20+tax. I mix of 5 gallons each brew day, which requires 1.5oz of product. Works out to be about $1.00 per batch. If I buy distilled water, it will cost about $1.00 per gallon, plus the star san. I just mix up a fresh batch with tap water each time I brew, then fill up a spray bottle for cleaning spigots, faucets, etc.

autobaun70 said:

I don't understand the gain of mixing with distilled water and reusing. I can get a 32 oz bottle from my local supply shop for about $20+tax. I mix of 5 gallons each brew day, which requires 1.5oz of product. Works out to be about $1.00 per batch. If I buy distilled water, it will cost about $1.00 per gallon, plus the star san. I just mix up a fresh batch with tap water each time I brew, then fill up a spray bottle for cleaning spigots, faucets, etc.

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I mix up ONE gallon of star san with distilled (or RO) water. The RO water comes from my house. I use that one gallon of sanitizer over and over and over. A 32 oz bottle of star-san that I bought in 2006 is about half full. It's very cheap to reuse, and it lasts indefinitely with distilled water. There is no reason to use 5 gallons of sanitizer on each brewday and bottling day. I keep a 1-gallon jug of sanitizer under my sink, and a spray bottle filled. That's all I need for months at a time.

I don't know the per batch cost, though. Maybe 2 cents?

Yooper said:

I mix up ONE gallon of star san with distilled (or RO) water. The RO water comes from my house. I use that one gallon of sanitizer over and over and over. A 32 oz bottle of star-san that I bought in 2006 is about half full. It's very cheap to reuse, and it lasts indefinitely with distilled water. There is no reason to use 5 gallons of sanitizer on each brewday and bottling day. I keep a 1-gallon jug of sanitizer under my sink, and a spray bottle filled. That's all I need for months at a time.

I don't know the per batch cost, though. Maybe 2 cents?

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hmm, I guess my process is just different. I greatly multi-task while brewing, and like to have the fermenter filled at least 1/3 of the way (I use a 13 gallon vittle vault). I like to just rotate it occasionally while everything else is going on to insure that every internal surface gets a good soaking.

Yooper said:

I mix up ONE gallon of star san with distilled (or RO) water. The RO water comes from my house.

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+1 to this. I use spray bottles extensively. Flasks for starters, airlocks, my big fermenters, and any other small stuff just needs a spray. For more than that, I keep a 5 gal bucket with RO/Star San and a spigot full and another bucket with a gamma lid so it's easy to close and re-open. That gets reused over and over and over until it's either just gross looking or the pH gets too high. Most of the time I throw it when it looks soiled, even though the pH is still plenty good. I know it's cheap, but no sense wasting time and money mixing up sanitizer every time I need it.

I mixed starsan with 18 M ohm (Milli-Q) eight months ago, and pH is still in the red. Distilled is approx 2 M ohm, IIRC.

MilliQ water rocks

autobaun70 said:

I like to just rotate it occasionally while everything else is going on to insure that every internal surface gets a good soaking.

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The thing about star san is it only needs 30 seconds of surface contact. The surface needs to be wet, and that's it. Soaking is pointless.

I've also got some nice 18 megaohm water on tap at work, I just bring home a gallon whenever I need it. Maybe that's why so many engineers are brewers

i have a 5gal bucket full of star san/water mix that i use to sterilize my kegs, fv, and tools. i use if for about 10 batches and then dumb it. i make sure my stuff is clean before it goes in anyways. i also have a 48oz spray bottle incase i forget to star san the scissors or something. have a 16oz spray bottle in my keezer to spray down the taps from time to time.

autobaun70 said:

I don't understand the gain of mixing with distilled water and reusing. I can get a 32 oz bottle from my local supply shop for about $20+tax. I mix of 5 gallons each brew day, which requires 1.5oz of product. Works out to be about $1.00 per batch. If I buy distilled water, it will cost about $1.00 per gallon, plus the star san. I just mix up a fresh batch with tap water each time I brew, then fill up a spray bottle for cleaning spigots, faucets, etc.

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For me it's not a matter of wanting to reuse it, so much as not wanting to mix up a fresh batch every time I brew or bottle. I mix up 2.5 gallons with distilled water and keep it in a covered bucket so it's ready whenever I need it. Like others have mentioned, I find a spray bottle very helpful for sanitizing many items.

chicken said:

For me it's not a matter of wanting to reuse it, so much as not wanting to mix up a fresh batch every time I brew or bottle. I mix up 2.5 gallons with distilled water and keep it in a covered bucket so it's ready whenever I need it. Like others have mentioned, I find a spray bottle very helpful for sanitizing many items.

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This. Waste not, want not. I've found that as long as the SS solution is clear, it passes the <3 pH test, so I pour it back in the jug and reuse it. The only stuff that gets soaked (I use a 30" wallpaper tray) are small parts. I use a spray bottle to coat everything else. This makes using Star San extremely economical.

Whatever floats your boat. I have 5 gallons in a carboy all the time, reuse it forever. I spray it in everything, soak everything and have no stress whatsoever over sanitization: when in doubt spray! My 32 oz container has lasted a couple of years.

Hey, someone above said he uses 1.5 ozs per 5 gallons. I have always used 1 oz per 5 gallons. Have I been doing it wrong all this time?

PJM said:

Hey, someone above said he uses 1.5 ozs per 5 gallons. I have always used 1 oz per 5 gallons. Have I been doing it wrong all this time?

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Starsan directions indicate 1oz./5gal.

Probably doesn't matter how much you add as long as the pH is below three and the mixed sanitizer looks clear. I bet you could use a lot less than an ounce in RO water, but haven't tried it.