I did a brew last night and after pouring the wort into the fermenter i realised I'd forgotten to empty out the sanitizer i'd put in it. It was about 300 ml of Chemsan (described as "A blend of phosphoric acid, benzenesulfonic acid and isopropanol.") (that is, 300 ml of the diluted sanitizer, which, since it has a 2ml to 1 litre dilution ratio, about 0.6 ml of the undiluted sanitizer). So, this ended up mixed in with about 30 litres of wort.

That comes out, assuming that it doesn't settle to the bottom or evaporate out or something like that, about a teaspoon (5ml) per pint. Chemsan is a "no rinse" sanitizer, which I assume means it's not super toxic, but I assumed that meant if there's a small residue left on a surface, rather than a whole teaspoon poured into a pint, so to speak.

I'm going ahead with the brew anyway, but this beer was intended for a friend's party (how typical that it would be the one i potentially poison!), and I was just trying to get a handle on the risk involved.

The instructions say:

Apply diluted solution on surfaces with a cloth, mop ,brush, sponge, spray or by immersion.

After 2 minutes contact time, drain solution thoroughly.

For all applications, allow to air dry, however surfaces must remain wet for at least two minutes.

Do not rinse after Chemsan application. 

The "do not rinse" thing kind of suggests that it's not going to poison anyone, but like I say I think they were talking about a thin residue on a surface.

  • 1
    Agree with other answer, I'd just ask the manufacturer. The likely case is- it probably won't cause you serious harm. However it might mess with your stomach a bit if you've had a few. I wouldn't start chuggin' before you find out ;)
    – rob
    Jun 21, 2021 at 17:07

1 Answer 1


That sucks. I'd probably try contacting the Chemsan manufacturer (https://chemisphereuk.com/) while things are fermenting. Or, just dump it and brew another batch.

  • Thanks. I have a feeling that they will say "We recommend that you throw it away" rather than take a risk of advising someone to poison their friends, even if they secretly think it will be fine, which makes it a bit pointless to ask them. But i'll try. Jun 22, 2021 at 12:18
  • They said "Although we say non rinse it wouldn’t be advisable to consume the beer with that much chemical in". I might keep it for myself anyway. Jun 22, 2021 at 13:45
  • That's a tough decision. Myself, I'd pitch it (due to the isopropyl and other constituents) and go buy a pack of my favorite off-the-shelf microbrew as a treat. It might not be enough concentration of isopropyl to kill or blind me, but It's just not worth adding the extra abuse on my organs. I'd rather I have an enjoyable time when I do it :)
    – HomeBrew
    Jun 24, 2021 at 9:09
  • last night I dumped it down the toilet (crying) and brewed another batch of the same recipe (minus the sanitizer). I asked about this on the Medical Science SE site and basically just got shouted at for even posting it :) Jun 24, 2021 at 13:44
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    Sorry bud. This hobby isn't real forgiving at times. During the pandemic last year, I bought several extract kit beers because my LHBS was closed up. These were around $30-$40 a pop. I still have a few sitting on my shelf. Probably over 6 months old. I made one a few weeks ago and it's not pleasant. Been trying to choke it down but it's just not enjoyable. I brewed a fresh AG batch last weekend and as soon as it's ready to keg, the extract is getting dumped. Happens to all of us at times. Hope your new batch turns out better 👍
    – HomeBrew
    Jun 26, 2021 at 12:59

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