Campden Solution prepared ahead of time?

Thought I'd make my own thread about this.

Normally when I brew and use my town water, I cut a campden tab in 1/4s and crush between 2 spoons, place in a small mason jar, add water, and shake for a few seconds. This usually gives a well-mixed solution which I add to the plastic jug before adding my water.

Now I wonder, would it be effective to prepare a 1/4 tab solution in a mason jar ahead of time and just keep them on the shelf?

Pressure canned?

That way I don't even have to crush the tablet and whatnot... I'm more curious than anything. Does the campden tab lose effectiveness after sitting around?

What do you smell when you put a campden tablet into water? SO2. Metabite is often called solid sulfur dioxide. If you can smell it it is leaving solution so if you want to premix be sure that you cap the container tightly. Other than loss to the air I don't see why it shouldn't have a reasonable shelf life.

Are you using the campden tables to sanitize? If you are, you can save time by mixing 2oz of Potassium Metabisulfite in a gallon of water and cap with a plastic cap. You can use this solution for months. Campden tablets are K-Meta (Potasssium Metabisulfite) mixed with a binder to form a tablet that is pre measured to aprox 1/32+ of a teaspoon (055mg).
Using in in the smaller fashon as you say, yes you can pre mix and store it for quite a while ( months ) Do not use metal, the K-Meta (actually the sulpher gas) will eat it. Use a plastic or glass container and lid. ( I keep some in a 750 bottle with a used plastic wine cork).
Hope this helped.

What I use it for is to remove the Chloramine from our city water system. When I called the city offices and asked the lady said the water guy told her we use chloramines because of our old pipes.

So I wondered if it would be reasonable to keep a mixture on hand and add some of the solution instead of digging out the tablets and crushing them each time. I'm already using a syringe to measure acid anyway. It would be pretty easy to mix up a solution and then draw up like 5 ml of the mixture and add to the water jug.

I never have smelled the stuff before. I'll have to do that next time I brew.

Yes, you can do that. It smells of sulpher, in that low of a dose it will be faint.

Get a small (~2oz) container of pure Kmeta. I hear that campden tabs can contain either NaMeta, or KMeta, depending on the day they are made.
Common dose is 1/16tsp/20g gallon.
Strange about ther earlier post saying campden tabs are 1/32, as I had heard one campden tablet treats 20 gallons.

Does anyone really care whether he gets 1.8 mg/L sodium or 3.3 mg/L potassium? These are the amounts required to treat water at 3 mg/L chloramine (see table in Sticky, https://www.homebrewtalk.com/f128/campden-tablets-sulfites-brewing-water-361073/).

cwi said:

Get a small (~2oz) container of pure Kmeta. I hear that campden tabs can contain either NaMeta, or KMeta, depending on the day they are made.
Common dose is 1/16tsp/20g gallon.
Strange about ther earlier post saying campden tabs are 1/32, as I had heard one campden tablet treats 20 gallons.

Click to expand...

For wine making, to kill wild yeast, use one campden tablet per gallon or 1/4 tsp K meta for 6 gallons.

As for conditioning water for brewing one tablet for 20 may be right.

ajdelange said:

Does anyone really care whether he gets 1.8 mg/L sodium or 3.3 mg/L potassium? These are the amounts required to treat water at 3 mg/L chloramine (see table in Sticky, https://www.homebrewtalk.com/f128/campden-tablets-sulfites-brewing-water-361073/).

Click to expand...

No, just that I had just heard that the dosage for water treatment is not the same when using units of 'campden tabs', since they mix and match the active ingredient (by weight only?). Also, I usually only see the little medicine bottles (for <$1/oz., by the way) of pure KMeta, not NaMeta. The main benefit of the pure product is there is no grinding/crushing needed, since it dissolves almost instantly, which seemed like the impetus for his desire to premix (although measuring a larger diluted volume might also be easier and more accurate). Also no 'cutting' tabs up, since it is available as is in salt grain size portions. I just eyeball it, myself. I pinch here, a dash there. As you said, it isn't that much added salt, even if you overdo it a bit.

I have read your post/report before, but it is fairly long for someone looking for a quick dosage guideline, especially a volumetric one for when your scale isn't handy (or you are just lazy, like me most times). After some protracted reading, I found someone who had converted worst case doses into tsp, dashes, and pinches. Also, about a hundred other posts (many with incorrect info) will show up in a search on the topic. It is a shame the Wiki isn't used more often than it is, especially since there is a time limit on editing posts.

BrewandWineSupply said:

cwi said:

Get a small (~2oz) container of pure Kmeta. I hear that campden tabs can contain either NaMeta, or KMeta, depending on the day they are made.
Common dose is 1/16tsp/20g gallon.
Strange about ther earlier post saying campden tabs are 1/32, as I had heard one campden tablet treats 20 gallons.

Click to expand...

For wine making, to kill wild yeast, use one campden tablet per gallon or 1/4 tsp K meta for 6 gallons.

As for conditioning water for brewing one tablet for 20 may be right.

Click to expand...

Not sure what the color war is about. It was obvious to me, even after the OP's first post, but certainly after his one stating it, that he was using it to remove chlorine/chloramine.
You stated that a campden tab is 1/32 tsp of kmeta/nameta. The recommended (worst case) dose for chloramine treated water, as I have heard many times, is 1 tab/20 gal. The recommended volumetric dose, as I have heard many times, of pure Kmeta is 1/16 tsp for chloramine. Something is strange with one of those dosing recs, not to mention your mass equivalent you stated as 055mg KMeta/campden tab, which sounds even stranger.

The link a few posts earlier has the dose by mass, which I can't recall with certainty at the moment.

What color war? just did a highlight and not a delete.
It was not clear to me until the third post what he was doing.
Yes you are right, 1 campden tablet is not 1/32 of a teaspoon, its 1/24 but I have not seen that in a set of measuring spoons. 1/32 is closest with out going over.
Yes you are right on the .055, just transposed the numbers as it should be 550 mg.
Sorry for my errors.
Here is where the info comes from:

BrewandWineSupply said:

Yes you are right, 1 campden tablet is not 1/32 of a teaspoon, its 1/24 but I have not seen that in a set of measuring spoons. 1/32 is closest with out going over.

Click to expand...

I believe the most common advice is to err on the safe side, since the additional load is so small, and may not even make it past the mash. The catch all recommendation (from memory) is ~700 mg KMeta per 20 gallons, which will neutralize the max concentration of chloramine permitted in many cities. One thread had found this amount to be ~1/16 tsp. There was also a tip to see how big your 'pinch' was by measuring/weighing ~10 pinches, so you can ballpark the amount needed for smaller volumes.

BrewandWineSupply said:

Yes you are right on the .055, just transposed the numbers as it should be 550 mg.
Sorry for my errors.
Here is where the info comes from:

Click to expand...

There is contradictory evidence that Campden tabs may contain either KMeta and/or NaMeta, even within the same brand. From memory, I think I read off a smaller packet/bottle of Campden tabs (from LD Carlson) that stated 'either/or' in the fine print (I then walked right over to the bulk chem area, and purchased a 4oz bottle of KMeta for $1.50). From other posts here, I believe it is swapped in equal weights, which would throw off molar calcs by ~20% (off the top of my head).

I have seen other LHBS's sub sodium cambden tablets for Potassium cambden tablets because they are cheaper. Not ethical though.