Star San Question

[Brew Engineer]

Not sure if this is the best place for this question, but I don't really care...

How long can I keep reusing a batch of Star-San? I've got a bucket of about 5 gallons in my basement (about 55-60 degrees). When I need to use it, I've been taking about half of it, heating it up and mixing it back to get the temp between 100 and 120. I've used this batch for three batches (brew days and bottling days). Is there any reason I can't keep using this stuff?

Am I doing anything that will decrease its effectiveness? Thanks!

[hopshead]

The sanitation archive will explain this better than I can, but..... When the ph of Starsan gets above 3 it is not longer effective. Depending on your water and the stuff you soak with starsan (i.e. how dirty it s) will reduce the length of time starsan is an effective sanitizer. I have had a few bad batches of beer in a row and after that I learned not to be to frugal with sanitation and cleaning supplies, so I generally mix a new batch of starsan before each bottling and brew day.

[BadRock]

Charlie Talley will tell you this all depends on the organic load. Tap water is by no means sterile, there is some organic matter as well as any organic matter that you have introduced. This depletes the sanitizer. Once it becomes cloudy it's shoot and\or like hopshead said the pH comes above 3, throw it out. The easiest way around this is mix up your solution in distilled water and use only what you need, then the rest will keep for months.

[DannyW]

Hmm. I know PBW works better warm/hot; did not know to do that with StarSan.

[J.Brew]

I second Danny although I'd like to know the effective temperature range of star san and if it functions better warm...I've been wondering for some time now and there's no information regarding temperature on the bottle.

[SunkenBier]

I wondered the same thing about temperature but decided since the bottle didnt say anything it must not have an affect.

[TMB]

Since I'm new to TBN, I'm also fresh on the archives. I remember the Star San guy saying that it would keep indefinitely if mixed with distilled. The minerals and stuff in normal tap would eventually react and kill the PH (and make it cloudy). I also remember him talking about a contact time of 30 seconds. So, who cares what the effective temperature is, if it's that fast. On the other hand, if you need to know, a general rule of thumb is that for every 10 degree C increase, the rate of reaction doubles. Works in the other direction too.

PBW should be warm because it generally needs a longer contact time to dissolve stuff.

Cheers

[Bugeater]

Even without checking with Charlie, I would shy away from heating Star San for a couple of reasons. First, I'm lazy and that would add an extra step.

The second reason is the possible effect of heat on the effectiveness of the sanitizer. I have worked a lot with chlorine as a sanitizer in food service establishments. Bleach works great in cold water. When you mix it into hot water, the chlorine ions are driven out of solution within a couple of minutes, rendering it ineffective as a sanitizer.

I realize that Star San is a different type of sanitizer, but I would still stay away from heating it for use without hearing from the manufacturer first.

Wayne
Bugeater Brewing Company