Starsan Shelf Life

[roadtodenali]

So I got tired of making big batches of Starsan so I did the math and figured the mix for a 26.5 oz spray bottle.

Do we have any idea what the shelf life is? How long can I keep a mix in a spray bottle and expect it to be effective?

Thanks

 

[petrolSpice]

Only way to know for sure is to measure the pH before you use it to ensure it's still effective. Shelf life will depend on the quality of the water used to mix it. Distilled water should provide the longest shelf life, that's what I use in my spray bottle.

 

[Yooper]

I mix up a gallon at a time, and use and reuse. I manage to spill most of it before the pH rises where it can't be used. I've been using star-san for nearly 8 years now, and I just bought my second bottle.

So I'd say it lasts a long, long time! The key is to use RO or distilled water, and discard it when it gets cloudy or the pH gets above a certain level (but I don't even know what that is, as I generally manage to spill it pouring it back into the jug and spray bottle before I worry about it losing effectiveness).

 

[roadtodenali]

That's right. Didn't even register that its an acidic sanitizer. I can't seem to find confirmation on the five start site (found msds and tech sheet but didn't see it on either) however it appears others have. The consensus seems to be below 3.5. Thanks guys.

 

[FuzzeWuzze]

I believe the Five Star guys said above 3ph.

 

[rave808]

How much do you mix for 1 gallon ?

 

[cluckk]

The Star San site also says that when it goes above that, rather than remixing you can "sweeten" it with a bit more.

 

[Dolomieu]

I have a small container sitting at work. Its 8 months old at this point. It was made with tap water and its cloudy. Its still at about 2.5 pH.

 

[roadtodenali]

I believe the Five Star guys said above 3ph.

Meaning above 3ph is NOT effective, right? Low PH is acidic.

 

[freisste]

Meaning above 3ph is NOT effective, right? Low PH is acidic.

Technically, anything under 7 is acidic...but yes, lower number = more acidic.

 

[roadtodenali]

How much do you mix for 1 gallon ?

Its 1oz to 5 gal and 1 gallon is 20% of 5 gal.

When you get into the really small Star San measurements I have had better luck converting to tsp. 6 tsp is 1 oz and 20% of 6 tsp is 1.2 tsp.

So a heaping tsp for 1 gal should get you there.

Anyone feel free to correct my math. I've been drinking.

Just as an FYI incase you want to do a spray bottle. 1/4 tsp should be good for around 26.5 oz. I just used a measuring cup to fill a 32 oz spray bottle up to 26.5 oz and marked it with a sharpie so it would be easy to fill going forward. All I need to do now is add 1/4 tsp and filler up to the line.

 

[petrolSpice]

I usually mix up 2.5 gallons at a time, and use a Tbsp of Star San.

 

[Clonefan94]

My guess is that it will last until it runs out. I mix up 5 gallons and re-use it all the time. I've kept it up to two months, with no loss of strength. The only reason I've swapped out for a new batch is that I've either used up a lot of it (spray bottles, forget to clean spoon after using in boil and just dropping it in star san bucket, etc.) or I find floaties in it.

I just keep adding to my spray bottle from the bigger container when it gets low. I check it with a test strip every time I use it and there's never been and issue.

 

[gromitdj]

^^^ That is also what I do, but at these quantities, it's easier to move to metric units for the StarSan. 1 oz. is approx. 30 ml., so 1 gallon gets 6 ml. I have a shot glass measuring cup that also has ml, but the cup that comes with cough syrup would work to measure it out.

 

[roadtodenali]

Technically, anything under 7 is acidic...but yes, lower number = more acidic.

Right. It wasn't the number so much as the "above" comment. In relation to 3ph, and given that it is an acidic solution, an acceptable situation should be on the acidic side of the number which would be "below" 3.

I was just confirming that the comment was the excusive statement meaning anything "above" 3 needs refreshing.

 

[Renoun]

^^^ That is also what I do, but at these quantities, it's easier to move to metric units for the StarSan. 1 oz. is approx. 30 ml., so 1 gallon gets 6 ml. I have a shot glass measuring cup that also has ml, but the cup that comes with cough syrup would work to measure it out.

Your math works out the same as mine. Don't forget that 1ml = 1cc. I have a 10cc syringe which makes it easy to measure out 6cc for a gallon, 3cc for a growler, or 1.5cc for a 1qt. spray bottle if I don't want to make up a larger quantity.

 

[gromitdj]

That's a great point too! I forgot that 1 ml is 1 cc I have few medicine syringes laying around.

 

[GASoline71]

I mix up 5 gallons of distilled water with Star-san in an old fermenter bucket. I just fill my spray bottles from there. I also use it to soak keg lines, taps, auto siphons, air locks, etc.... Just put the lid on when finished and use it for about 6 months. I just dumped my batch out today, and I had mixed it back in July. Next time I brew... I will whip up another 5 gallon batch and be good for another 6 months.

Gary