How Long Does Diluted Sanitizer Last?

[drtomc]

Hi All,

I regularly use Starsan and Iodophor (though not at the same time). I have not found anything saying how long they are good for once diluted. I usually tip the diluted stuff at the end of the task, but that wastes quite a bit. Do they last hours? Days? Weeks?

T.

 

[MarkBastard]

With Starsan it's meant to last until it goes cloudy, but people here often say that's only when used with pure water. Not tap water.

For me it depends on the task. I still keep Starsan in a spray bottle for a while to do some basic sanitising but I wouldn't sanitise a keg with anything but a fresh mixture.

 

[kuntushi]

The technical sheet can be found at: http://www.fivestarchemicals.com/tech/starsan.pdf

It only mentions it once, but after "part soaking" it says "When solution begins to cloud, sweeten with Star San or Phosphoric Acid. Solution must remain at a pH at 3 or below to maintain proper sanitizing level."

I personally made up a big batch of 20L in a sealed drum with a tap on it. It's nearly all used up, but in the 3 weeks since we made it, we've used it for the primary, secondary and bottles of a wheat beer. I tasted one last night (1 week after bottling) and it didn't seem to have an infection. Admittedly, the last time it was used was 2 weeks ago (for the bottles). I used it again yesterday, but won't know if those few bottles weren't santised properly until they start exploding. But the solution wasn't cloudy, so I think it'll be right.

 

[peaky]

I also use a spray bottle, it's only 1 litre so it gets refilled every few brews/bottling, prob refill every 2 weeks or so. I find the amount of StarSan that gets used during a bottling or fermenting procedure is minimal, I just mix a fresh lot every time. I've fermented and bottled 10 brews with the current bottle of starsan I've got and I've used about 3oz.

I would imagine starsan would only get cloudy by reusing it? Or does it become cloudy over time just from being diluted?

 

[Hogan]

Heard a podcast from the manufacturer of Iodophor. He says that when the mixture is red the bugs are dead. When it turns clear (after about 24 hours) then it has lost its effectiveness. I find that the mix when confined to a spray bottle stays brownish for some time but that could be the product staining the plastic.


Cheers, Hoges.

 

[keifer33]

I'm sure someone will correct me if I'm wrong but if using tap water and storing for extended periods it would lose it's effectiveness due to minerals in tap water and will drop below the required ph. This would also require everyones tap water to be the same for a comparison on time people have been able to store it successfully. It might be worth while investing or borrowing a ph tester and running a trial to get an idea of storage while still above the required ph with the water you will be using.

Using distiller or reverse osmosis water willbe costly and alitmore than another bottle of starsan.

 

[MarkBastard]

I basically put a 1L mixture in the keg and use co2 to force it out, then collect it and fill up my 500ml spray bottle and use the other 500ml for other things (e.g. the filter + housing).

The 500ml spray bottle is used to spray disconnects etc but I keep it around after the kegging procedure and use it for cleaning the tap after hydromatre samples and things like that. It's probably not as affective but it doesn't bother me. The fermenter tap gets fresh starsan on it before the real racking anyway.

 

[Bubba]

I use iodophoe in a spray bottle and keep it in the fridge when not in use.
Basically it is OK to use as long as it is discoloured, when it clears it is no good.
A bottle will last me weeks in the fridge once diluted.

 

[Sammus]

I use starsan and reuse it, emptying it back into the same bucket everytime. I remix it (1L) every month or so, reuse it for all my kegs, fermenters, bottles, etc. No infections yet...been doing this for years now. Tap water too, not distilled.

 

[Nick JD]

Is it okay on skin? Should I be washing it off if it gets on my hands?

 

[marksfish]

the dilute solution of starsan is o.k if below a p.h of 3.5, and on a b.n podcast the maker said you can use it for tinea!.

 

[sama]

Is it okay on skin? Should I be washing it off if it gets on my hands?

never had any iritation on the skin(in the correct dilution rate)and i spray my hands and forearms wit hit when handling/culturing yeast. I havent bothered to wash it off afterwoods.Apparently the warning label is a prerequisite of the food regulators in the usa,but the **** is harmless at the correct concentration podcast on sanitation with 5 star chem guy

 

[felten]

It ***** my hands up, I have to wear gloves.

 

[zebba]

I just poured some down the sink. Wasn't cloudy, but a very strong sulphur smell was coming from the solution. Stored in glass, regular tap water - 2 weeks old. Anyone else experienced the stink from it? Fresh stuff I mixed up smells fine.

 

[gregs]

Would it be fair to say that when using Starsan, if the correct PH of 3 is required for sanitation then a PH test of the mixture a week or so later should tell you if it is still good to use, give it some thought.

 

[manticle]

A pH test would be the obvious solution.

Myself I only mix up 500 mL at a time and usually brew enough so that it is used up pretty quickly. On the odd ocassion it turns cloudy I turf it. I also use other sanitisers in conjunction though so between them all I reckon I'm safe if I'm clean.

 

[sama]

It ***** my hands up, I have to wear gloves.



what happens to them?

 

[thesunsettree]

i use it in a 500ml spray bottle, and often spray it on my hands purposefully with no issues. obviously it may affect some people because it is an acid.

matt

 

[felten]

It dries up my delicate skin, it takes a lot of moisturiser (mens moisturiser of course) to get them back into shape.

what happens to them?

 

[hoohaaman]

the dilute solution of starsan is o.k if below a p.h of 3.5, and on a b.n podcast the maker said you can use it for tinea!.

Had it last months,test the pH every now and then.Tap water only.Turns milky with repeated use,but I trust the maker and continue using it while at correct pH levels.

Interestingly he also said PBW was still effective even if the solution was black in colour,also true.

Great products