Author Topic: Contact time for Potassium Metabisulfite  (Read 1304 times)

Offline ynotbrusum

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Contact time for Potassium Metabisulfite
« on: March 18, 2013, 03:08:42 PM »
I racked over my Berliner Weisse and mixed a gallon of water with an ounce of potassium metabisulfite to sanitize the tubing and autosiphon, bung and airlock.  Any idea how long the soak would need to be at that concentration (I used a wallpaper tray to hold the tubing, canes, bung and airlock).  That will tell me whether I need to soak the 6 gallon fermenter with 6 gallons of the same concentration or just swirl up a gallon in it.
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Offline denny

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Contact time for Potassium Metabisulfite
« Reply #1 on: March 18, 2013, 03:58:21 PM »
Can't answer your question, but I've always been told that metabisulphite isn't a good sanitizer for beer.  It works for wine because of the lower pH and higher alcohol content.  Is that incorrect?
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Offline ynotbrusum

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Re: Contact time for Potassium Metabisulfite
« Reply #2 on: March 18, 2013, 05:17:50 PM »
Typical that my LHBS said to use it to sanitize after doing a sour - he has led me astray before...anyway, maybe the better question for me to ask is "what sanitizer do you sour brewers use on your equipment?"  I would hate to have to dedicate a second set of equipment to just sour beer handling.
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Online mtnrockhopper

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Re: Contact time for Potassium Metabisulfite
« Reply #3 on: March 19, 2013, 09:04:24 AM »
Can't answer your question, but I've always been told that metabisulphite isn't a good sanitizer for beer.  It works for wine because of the lower pH and higher alcohol content.  Is that incorrect?
Denny, you're right if you're talking about knocking back wild yeasts in wort vs must. But ynot's asking about making a sanitizer with a high concentration of sulfite in water, which is common (in winemaking anyway).
 
I heard two minutes is fine. Add some to your carboy and shake, then let it sit with a stopper on. The sulfur fumes do as much of the work as the liquid. Many also add citric acid to the water bring the pH down - a low pH makes the sulfite work better.
 
I'm not sure why your LHBS recommended sulfites over other sanitizers.  I don't think it's necessarily better than star-san or other sanitizers. I think you can get away with one set if you are super careful about cleaning. You could get a stainless steel racking cane and just keep a second set of tubes.
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Offline kramerog

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Re: Contact time for Potassium Metabisulfite
« Reply #4 on: March 19, 2013, 01:21:16 PM »
starsan is what I use.  While I have gotten away with using the same equipment for sour and non-sour beer, I know that I should dedicate some tubing to sours as it is hard to keep tubing really clean.
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Offline dbarber

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Re: Contact time for Potassium Metabisulfite
« Reply #5 on: March 20, 2013, 06:45:26 AM »
I use starsan as well.  I'm a little paranoid and have dedicated tubing, siphon and airlocks for sours.
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Offline euge

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Re: Contact time for Potassium Metabisulfite
« Reply #6 on: March 20, 2013, 07:36:48 AM »
I can only think of any good reason would be using it in the beer to halt the fermentation process and preserve flavor.
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Offline tomsawyer

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Re: Contact time for Potassium Metabisulfite
« Reply #7 on: March 20, 2013, 10:35:21 AM »
Kmeta won't work in beer because you need a pH below 4.0 for it to produce any decent quantity of SO2.  Above that it is ineffective.  some wines are up close to 4.0 and you have to add a rather large dose of kmeta for it to produce enough free SO2.

As for a sanitizer, if you add some acid to your mix it will work fine.  Be careful of the fumes, it'll smell of sulfur from the SO2.  A couple spoonfuls of acid blend or even viniegar, of course you'll have to rinse afterwards.  You could probably use phosphoric and not rinse as long as you drain it well.  Typically a concnetration of 1% kmeta in acidified water is used as a sanitizer for winemaking.  as for contact time, a few seconds is all it'll take to sanitize.

I use starsan, much easier.
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Offline ynotbrusum

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Re: Contact time for Potassium Metabisulfite
« Reply #8 on: March 20, 2013, 11:24:31 AM »
I've always used Star San, but I just thought maybe it was too dilute at 1oz /5gal to kill the bugs that are in a sour beer.  My first sour, so that is why I asked.  I'm not adding it to beer or wine.  Thanks for the insight - sounds like I will soak it in some Star San next just to be sure and probably use the tubing for only sours - tubing is cheap!
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Offline tomsawyer

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Re: Contact time for Potassium Metabisulfite
« Reply #9 on: March 20, 2013, 02:01:46 PM »
I've done many sours/lambics, and cleaning with PBW plus sanitizing with Starsan has always worked for me.  I do keep a separate autosiphon for them but thats about it.  I've successfully sanitized plastic buckets, Better Bottles and certainly glass carboys.
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Offline ynotbrusum

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Re: Contact time for Potassium Metabisulfite
« Reply #10 on: March 20, 2013, 03:40:48 PM »
I've done many sours/lambics, and cleaning with PBW plus sanitizing with Starsan has always worked for me.  I do keep a separate autosiphon for them but thats about it.  I've successfully sanitized plastic buckets, Better Bottles and certainly glass carboys.

Thank you Sir!  I will follow your direction.
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Offline malzig

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Re: Contact time for Potassium Metabisulfite
« Reply #11 on: March 21, 2013, 04:06:24 AM »
Just make sure you wash first.  Washing with a peroxide cleaner, like PBW or Oxyclean, will likely kill and remove most of the bugs before it ever even sees sanitizer.