Campden Tablets and Foam

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SaltNeck

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Does anyone know the science behind the foam produced by a campden tablet dissolved in water and then boiled?

For example, dissolving a campden tablet in a gallon of water and boiling it will produce the foam.

Maybe the more campden used per volume of water the more foam is produced?

What is the white foam that forms?
What is it comprised of?
Why or how does it form?
Is it safe to leave in a beer?

I know campden tablets are used in chlorine/chloramine removal and sanitation but what is the raison d'être of the foam?
 
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SaltNeck

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Good point. Don't have any Na or K metabisulfite ATM. Anyone willing to boil a gallon (half gallon?) of tap water with a teaspoon of one these chemicals and report how much foam they get?
 

MaxStout

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Good point. Don't have any Na or K metabisulfite ATM. Anyone willing to boil a gallon (half gallon?) of tap water with a teaspoon of one these chemicals and report how much foam they get?

I'm on it.

Edit: Boiling 1 tsp. of sodium metabisulfite in about 1/2 gal RO water in the microwave. Will keep you posted.
 
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Bramling Cross

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I'm making pasta atm, once my DC tap water hits a boil I'll toss in a crushed campden tablet and see what happens. If that doesn't create foam, I'll toss in a non-crushed tablet.

You see where I'm going with this?

Edit: Crushed campden tablet = zero foam with DC tap.

Edit II: Some modest foam off of the nucleation from an un-crushed tablet. No honest to goodness foam, though. Bummer.

DC tap is really forgiving brewing water, so I'm assuming that you're not seeing a campden phenomenon so much as a your water phenomenon.
 
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MaxStout

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(Used stovetop, microwave too slow.)

Vigorous boil for 2-3 mins, no foam.
metaboil.jpg
 
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SaltNeck

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Here's some pictures of it, tried a different vessel this time, rinsed it and pre-boiled some water in it. Crushed the Campden between two spoons and put it in at the start of the heating cycle. Like you guys said, I suspect there's something in the tap water or some detergent left behind. It doesn't seem to happen w/o the Campden though.
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Bramling Cross

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Since neither I nor @Bramling Cross could get any foaming, maybe there is either something in your water, or perhaps some detergent film or debris in the boil vessel causing nucleation?

For @#(%* and giggles, once I get done with dinner I'll run a small, filtered, acidified, and mineralized batch of DC tap that is set up for brewing. I doubt there'll be a change though.
 

Bramling Cross

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Here's some pictures of it, tried a different vessel this time, rinsed it and pre-boiled some water in it. Crushed the Campden between two spoons and put it in at the start of the heating cycle. Like you guys said, I suspect there's something in the tap water or some detergent left behind. It doesn't seem to happen w/o the Campden though.View attachment 751237 View attachment 751238 View attachment 751239

Nothing at all like that on my end. That's some chunky looking water.

Boil your water, decant, then do it again and see what happens. Moreover, grab some distilled water at the grocery store tomorrow and try again. I think you'll see different results.
 
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SaltNeck

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Not sure what "chunky water" is, but I believe the town softens the water.
 

Bramling Cross

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Yeah, by "chunky" I mean not soft. It has stuff in there, and not just a little bit of stuff in there. That's a lot of stuff. Which may or may not be good. It's up to you to figure it out.
 

MaxStout

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Here's some pictures of it, tried a different vessel this time, rinsed it and pre-boiled some water in it. Crushed the Campden between two spoons and put it in at the start of the heating cycle. Like you guys said, I suspect there's something in the tap water or some detergent left behind. It doesn't seem to happen w/o the Campden though.View attachment 751237 View attachment 751238 View attachment 751239

So you're adding it before it comes to a boil, and not adding it into the boil. If you did the latter, I would say nucleation from the powder being added.
 
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SaltNeck

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Yeah, by "chunky" I mean not soft. It has stuff in there, and not just a little bit of stuff in there. That's a lot of stuff. Which may or may not be good. It's up to you to figure it out.

I've been drinking this water for years and I haven't notice anything ... o_O
 
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SaltNeck

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So you're adding it before it comes to a boil, and not adding it into the boil. If you did the latter, I would say nucleation from the powder being added.

Yes, adding the crushed campden tablet to the cool water before the heat is turned on.
 

MaxStout

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Yes, adding the crushed campden tablet to the cool water before the heat is turned on.

That weeds out nucleation by adding to boil.

Try with a clean pot and distilled or RO water. If it doesn't foam, it's likely your tap water. If it still foams, there's something fishy about those campden tabs.

Edit: I assume you've been completely dissolving the campden before you bring the water to a boil? No undissolved bits of campden floating around in there to cause nucleation?
 

Bramling Cross

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I've been drinking this water for years and I haven't notice anything ... o_O

Relax! Your water is perfectly fine and very healthy.

As water approaches a boil some chemistry starts to happen and minerals that used to be stable within the solution suddenly become free. That's why your water gets cloudy before it starts to boil. Your water is fine as drinking water, guzzle it with abandon!
 
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SaltNeck

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Edit: I assume you've been completely dissolving the campden before you bring the water to a boil? No undissolved bits of campden floating around in there to cause nucleation?

Yes, I do stir until it appears to be completely dissolved in the cool water. Seems to dissolve easily and doesn't take much stirring.
 

Bramling Cross

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For @#(%* and giggles, once I get done with dinner I'll run a small, filtered, acidified, and mineralized batch of DC tap that is set up for brewing. I doubt there'll be a change though.

Nope, no difference. Campden does not create foam in my DC water that has been treated with acid and minerals for brewing a pilsner beer. I tried it crushed, then I dropped a tablet in the water.

No foam.

I suppose that I could build a small batch of chunky English Porter water...but I expect the result will be the same. I've been brewing for thirty years, foamy water isn't something that I've ever seen.
 
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Bramling Cross

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I'm bored, so I built some porter water.

No foam crushed. No foam with a tablet. It was very cloudy and chunky looking as it approached the boil, but no foam.

Edit: In the prior two posts I spanned the gamut of decent brewing waters. I built a pilsner water that resides on the soft side of the brewing spectrum and a porter water that is legendarily chunky. Neither foamed.

Whatever you have going on there isn't related to campden tablets added to good brewing water in clean brewing vessels.
 
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SaltNeck

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Thanks for testing this guys.

Boiling my regular tap water doesn't produce the foam (see picture) but adding the campden tablet does.

As previously mentioned it might have something to do with the binder in the tablet.

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To produce foam, of course.

I will be the fool that asks, as this is not my process for prepping my HLT. Why are you bringing the water up to a boil, if there is any other reason than to make it foam?

I filter my water and add 1/4-1/2 Campden tablet to 7-10G of HLT H2O, which only gets heated to 165F normally before mash-in. So, no foam, but also, no boiling.

I am just curious.
 
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SaltNeck

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Well actually, since I only do 1-2 gallon batches my sparge water got to boiling accidentally and I noticed it was foaming... the only thing I had added to it was some crushed campden tablet so logically I tested it and boiled some more water with crushed campden in it and voila it foamed. That prompted me to come here and make this post seeing if anyone else had experienced this.
 

IslandLizard

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For example, dissolving a campden tablet in a gallon of water and boiling it will produce the foam.
That's one hefty overdose!!!
1 Campden tablet will treat 20 gallons of water (removing Chlorine and Chloramines).

You don't have to use Campden tablets, just use a proportional amount of K-Meta (or Na-Meta) powder. IIRC, I paid $2.00 for a pound of K-Meta.
 
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SaltNeck

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That's one hefty overdose!!!
1 Campden tablet will treat 20 gallons of water (removing Chlorine and Chloramines).

You don't have to use Campden tablets, just use a proportional amount of K-Meta (or Na-Meta) powder. IIRC, I paid $2.00 for a pound of K-Meta.

True, but smaller amounts also foam and I certainly don't use that much when brewing. Normally I would use K or Na meta but, as previously mentioned, I ran out and decided to use these campden tablets.
 
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