Ss Brewing Technologies Giveaway!

Home Brew Forums > Home Brewing Beer > Brew Science > Conflicting info on amount of Sodium Metabisulfite to de-Chlorinate/de-Chloraminate
Reply
 
LinkBack Thread Tools
Old 02-16-2010, 12:25 AM   #1
hafmpty
Feedback Score: 1 reviews
Recipes 
 
Join Date: Jan 2010
Location: Cincinnat, OH
Posts: 294
Liked 12 Times on 11 Posts
Likes Given: 5

Default Conflicting info on amount of Sodium Metabisulfite to de-Chlorinate/de-Chloraminate

So I seem to be finding conflicting testimony on HBT and the Internet (surprise!) on how much SODIUM METABISULFITE powder I should use to treat my strike and sparge water. For the sake of simplicity let's say I use 20 gallons of water total.

I've been reading that ONE .5gram Campden Tablet is 1/16tsp of Sodium Metabisulfite and will treat 20 gallons of water.

So why am I reading on here that people use 1/8tsp, 1/4tsp, or even 1/2tsp to treat 10 gallons of water. Based on my numbers at least that's overkill. Or is it? Are my numbers wrong? At most, people should be using like 1/32tsp for treating 10 gallons or 1/16tsp for treating 20 gallons. Is is just not that big of a deal? I'm going to be adding brew salts and I know they have to be pretty exact. Maybe Sodium Metabisulfite isn't the same as that?

I'm trying to figure out how much I should use to treat my water. Thanks!

__________________

Last edited by hafmpty; 02-16-2010 at 01:50 PM.
hafmpty is offline
 
Reply With Quote Quick reply to this message
Old 02-16-2010, 01:17 PM   #2
Saccharomyces
Be good to your yeast...
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Saccharomyces's Avatar
Recipes 
 
Join Date: Jun 2008
Location: Pflugerville, Texas
Posts: 5,444
Liked 80 Times on 52 Posts
Likes Given: 2

Default

Our water has a ludicrous amount of chloramine, and one campden tablet in 20 gallons works like a charm. You are correct that would be about 1/16 of a teaspoon in powder form. It doesn't hurt to add too much though since it will just boil off.

Since so little is almost impossible to measure, I crush up one tablet and dissolve it in a few cups of water which then gets added to the four buckets of water in equal 1/2 cup portions.

I have also read of folks using vitamin C tablets to dechlorinate water.

__________________
[How to Calculate Mash Efficiency | Do I Need a Yeast Starter? | My Ghetto Fermentation Chamber | Twitter | 6 Gal. HDPE Fermenters | Slanting Yeast | No Sparge Brewing]

Quote:
Originally Posted by Soperbrew
big brother only monitors facebook and untappd
Saccharomyces is offline
 
Reply With Quote Quick reply to this message
Old 02-16-2010, 01:36 PM   #3
Bobby_M
Vendor and Brewer
HBT_SPONSOR.png
Vendor Ads 
Feedback Score: 2 reviews
 
Bobby_M's Avatar
Recipes 
 
Join Date: Aug 2006
Location: Whitehouse Station, NJ
Posts: 22,014
Liked 976 Times on 653 Posts
Likes Given: 28

Default

Quote:
Originally Posted by hafmpty View Post
So I seem to be finding conflicting testimony on HBT and the Internet (surprise!) on how much SODIUM METABISULFITE powder I should use to treat my strike and sparge water. For the sake of simplicity let's say I use 20 gallons of water total.

I've been reading that ONE 5.5gram Campden Tablet is 1/16tsp of Sodium Metabisulfite and will treat 20 gallons of water.

So why am I reading on here that people use 1/8tsp, 1/4tsp, or even 1/2tsp to treat 10 gallons of water. Based on my numbers at least that's overkill. Or is it? Are my numbers wrong? At most, people should be using like 1/32tsp for treating 10 gallons or 1/16tsp for treating 20 gallons. Is is just not that big of a deal? I'm going to be adding brew salts and I know they have to be pretty exact. Maybe Sodium Metabisulfite isn't the same as that?

I'm trying to figure out how much I should use to treat my water. Thanks!
I don't know where you get your campden tabs, but I've never seen a 5.5 gram one. That would look like a horse pill. Mine weigh .5 grams (500mg) each. You're right about 1/16th tsp in powder form is right for 20 gallons. I use a "small pinch" as my exacting measurement.
__________________
BrewHardware.com
Sightglass, Refractometer, Ball Valve, Weldless bulkhead, Thermometer, Decals, Stainless Steel Fittings, Compression Fittings, Camlock Quick Disconnects, Scale, RIMS tube, Plate Chiller, Chugger Pump, Super Clear Silicone Tubing, and more!

New Stuff?

Last edited by Bobby_M; 02-16-2010 at 01:40 PM.
Bobby_M is online now
 
Reply With Quote Quick reply to this message
Old 02-16-2010, 01:39 PM   #4
GilaMinumBeer
In yo' garage, steelin' yo parts.
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
GilaMinumBeer's Avatar
Recipes 
 
Join Date: Jan 2008
Location: Oblivion
Posts: 47,643
Liked 4742 Times on 4380 Posts
Likes Given: 59

Default

I use an 1/8th tsp because that is the smallest measuring spoon I have and I don't feel like weighing out a gram of powdered campden.

Yes, I usually get the powdered stuff or I run the tablets through a coffee mill to powder them. Makes dissolving the chemical much easier.

__________________
GilaMinumBeer is offline
 
Reply With Quote Quick reply to this message
Old 02-16-2010, 01:49 PM   #5
hafmpty
Feedback Score: 1 reviews
Recipes 
 
Join Date: Jan 2010
Location: Cincinnat, OH
Posts: 294
Liked 12 Times on 11 Posts
Likes Given: 5

Default

Quote:
Originally Posted by Bobby_M View Post
I don't know where you get your campden tabs, but I've never seen a 5.5 gram one. That would look like a horse pill. Mine weigh .5 grams (500mg) each. You're right about 1/16th tsp in powder form is right for 20 gallons. I use a "small pinch" as my exacting measurement.
Yeah, sorry. My bad. I should have put .5g. Original thread will be edited to reflect the correct amount.
__________________
hafmpty is offline
 
Reply With Quote Quick reply to this message
Old 02-18-2010, 05:18 PM   #6
AiredAle
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2006
Posts: 474
Liked 17 Times on 13 Posts

Default

Campden tablets contain sodium metabisulfite, Na2S2O5, they weigh 0.44 g according to wikipedia. According to the chemistry, 1 milligram of chlorine is neutralized by 1.5 mg of bisulfite. Typically municipal water has 3 or less ppm of Cl2 or NH2-Cl (chloramine). So, if one liter of muni water has 3 mg of chlorine, it needs 4.5 mg of bisulfite for chlorine removal. 20 gallons is roughly 80 liters, so 3 X 80 = 240 mg chlorine X 1.5 mg bisulfite = 360 mg bisulfite to neutralize the chlorine in 20 gallons. Since one tablet is 440 mg and probably includes some binder to hold it together, the one tablet per 20 gallons makes sense.

__________________
AiredAle is offline
 
Reply With Quote Quick reply to this message
Old 02-18-2010, 06:47 PM   #7
hafmpty
Feedback Score: 1 reviews
Recipes 
 
Join Date: Jan 2010
Location: Cincinnat, OH
Posts: 294
Liked 12 Times on 11 Posts
Likes Given: 5

Default

Thanks a lot AiredAle. That was very helpful. I'll use those numbers to help me figure out the amounts to put in my water for treatment. It seems like you'd have to try to mess up your water with Campden Tablets. I think I was more concerned with the actual numbers of sulfites going into the water that would be "leftover" than I was anything else. But it seems like the numbers are so minimal it really isn't a problem. Thanks again all.

__________________
hafmpty is offline
 
Reply With Quote Quick reply to this message
Old 11-29-2010, 03:48 AM   #8
DeafSmith
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
DeafSmith's Avatar
Recipes 
 
Join Date: Jan 2009
Location: Richardson, TX
Posts: 1,447
Liked 33 Times on 31 Posts
Likes Given: 9

Default

FYI, I just weighed out 1/8 tsp of potassium metabisulfite powder (packed down) at just about 800 milligrams. So 1/16 tsp would be 400 mg (more or less depending on the accuracy of my measuring spoon) or just almost equivalent to one Campden tablet. I haven't seen any recommendations for using different amounts of K meta vs. Na meta, so I would assume that 1/16 tsp of either is about right for 20 gallons of water.

__________________
DeafSmith is offline
 
Reply With Quote Quick reply to this message
Old 11-29-2010, 12:23 PM   #9
ajdelange
Senior Member
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2010
Location: McLean/Ogden, Virginia/Quebec
Posts: 5,944
Liked 588 Times on 486 Posts
Likes Given: 16

Default

When I came up with the 1 tablet per 20 (US) gal number originally I assumed:
1. A Campden tablet was made up of 695 mg of potassium metabite (because the Campden tablets I had at the time I wrote the article weighed 695 mg and were made of potassium metabite). There could, I suppose, also have been some binder in there.
2. The water being treated contained 3 mg equivalent free chlorine - all as chloramine. 3 is the highest concentration allowed by regulation.

WRT 1 above - Campden tablets can be made of sodium metabite in which case (1) 695 mg tablet would treat more than 20 US gal. One mg chloramine (as Cl) requires 3.127 mg potassium metabite but only 2.674 mg sodium metabite (because sodium is lighter than potassium). The ratio is 1.169 thus you can use 17% less of the sodium salt. Campden tablets may weigh more or less than 695 mg depending on whose you buy.

WRT 2 above -Obviously, if you know that the available chlorine level is less than 3 mg/L you can use less metabite. Furthermore, it takes about twice as much metabite to reduce chloramine as it does chlorine so if you know that part of the available chlorine is chlorine you can use less.

In other words, the 695 mg/20 gal number is designed to protect you against the worst case and is more than is needed in any other case. The good news is that the products of reacted and unreacted metabite (with the exception of the cation) are beneficial to beer in various ways so over dosing is not a problem. OTOH you can use the incremental approach. Crush a Campden tablet with a spoon and add pinches at a time until the chorine odor is gone. When it is, so is the chloramine.

[Edit] The comment about excepting the cation does not mean that they are detrimental. Neither sodium nor potassium in the amount found in a Campden tablet could be considered harmful.

__________________

Last edited by ajdelange; 11-29-2010 at 02:57 PM. Reason: See [Edit]
ajdelange is offline
 
Reply With Quote Quick reply to this message
Old 11-29-2010, 03:07 PM   #10
DeafSmith
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
DeafSmith's Avatar
Recipes 
 
Join Date: Jan 2009
Location: Richardson, TX
Posts: 1,447
Liked 33 Times on 31 Posts
Likes Given: 9

Default

Quote:
Originally Posted by ajdelange View Post
When I came up with the 1 tablet per 20 (US) gal number originally I assumed:
1. A Campden tablet was made up of 695 mg of potassium metabite (because the Campden tablets I had at the time I wrote the article weighed 695 mg and were made of potassium metabite). There could, I suppose, also have been some binder in there.
2. The water being treated contained 3 mg equivalent free chlorine - all as chloramine. 3 is the highest concentration allowed by regulation.

WRT 1 above - Campden tablets can be made of sodium metabite in which case (1) 695 mg tablet would treat more than 20 US gal. One mg chloramine (as Cl) requires 3.127 mg potassium metabite but only 2.674 mg sodium metabite (because sodium is lighter than potassium). The ratio is 1.169 thus you can use 17% less of the sodium salt. Campden tablets may weigh more or less than 695 mg depending on whose you buy.

WRT 2 above -Obviously, if you know that the available chlorine level is less than 3 mg/L you can use less metabite. Furthermore, it takes about twice as much metabite to reduce chloramine as it does chlorine so if you know that part of the available chlorine is chlorine you can use less.

In other words, the 695 mg/20 gal number is designed to protect you against the worst case and is more than is needed in any other case. The good news is that the products of reacted and unreacted metabite (with the exception of the cation) are beneficial to beer in various ways so over dosing is not a problem. OTOH you can use the incremental approach. Crush a Campden tablet with a spoon and add pinches at a time until the chorine odor is gone. When it is, so is the chloramine.

[Edit] The comment about excepting the cation does not mean that they are detrimental. Neither sodium nor potassium in the amount found in a Campden tablet could be considered harmful.
So if I'm doing this correctly, for K meta I can multiply 3.127 mg by 3 mg of Cl per liter to get 9.38 mg K meta per liter needed to neutralize 3 mg Cl per liter and then multiply 9.38 by 76 liters per 20 gallons to get 713 mg K meta needed for 20 gallons as the maximum needed? So it might be advisable to use 1/8 tsp (about 800 mg) of the K meta powder per 20 gallons water in order to be certain of neutralizing all the chloramine?
__________________
DeafSmith is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do campden tablets de-chlorinate water King of Cascade All Grain & Partial Mash Brewing 71 05-08-2013 08:53 PM
Does a small amount of mead need to age the same amount of time as a larger batch? Apendecto Mead Forum 4 12-08-2009 10:08 AM
Secondary temps--Search gives conflicting info xcap Beginners Beer Brewing Forum 6 04-28-2009 06:29 PM
Conflicting Info. Set me straight? BWRIGHT Beginners Beer Brewing Forum 19 01-25-2008 05:43 PM
Sodium Metabisulfite magno Mead Forum 4 06-22-2006 02:21 AM