Sodium metabisulfite for water treatment

Hello,
I live not far outside Edinburgh and have never noticed a chlorine smell from my water before so never bothered treating it when brewing.. but just recently the water has started smelling quite strongly of chlorine for some reason.

So thinking I should sort that out before using for the next batch. I know most people use campden tabs... but I've got an unopened tub of sodium metabisulfite lying around which I know I could use instead, if I could work out how to measure the right amount..

So questions:

1. Can anyone tell me the rate of sodium metabisulfite to water I should be using? (have seen much speculation about this via google but little by way of consensus). I brew smaller batches than most btw - about 12L at a time.

2. Given the rate will likely be less than a gram.. any tips how to measure such a small amount? I thought about dissolving a gram in a set amount of water and then using an accurate syringe to dispense that (I have a 5ml syringe) - but then my brain started hurting trying to work it out.

3. Does it really matter being accurate - am I likely to ruin a batch by throwing in a good old pinch? Is too much bad?

4. Probably a stupid question, but do you only add it when the water is unadulterated? You can't add it to the wort?

Cheers for any help!
D.

If riding the chlorine from the water is your only concern I'm not sure I'd add anything to the water. If you are trying to build your water to a specific
profile then adding minerals and other chemicals is the way to go.

Chlorine is probably the easiest thing to get out of your water. First you could filter it with a simple inline home filtration system. Second if you don't want to spend the money on filters, measure out your brewing water the night before you brew and the chlorine will dissipate. Also boiling your water for 15-20 minutes prior to adding your extract/grains will drive off chlorine. No real need for chemicals.

You MUST add SO2 to get rid of the Chlorine compounds.
The easiest way is 1/2 a Campden tablet in the HLT per 5 gals.
Now here is where I fail you, I can't remember the weights of Campden tablets or the equivalent weight of Sod Met.
Moley has these figures at his finger tips!
A pinch, thumb and finger, of Sod Met will solve your problems.
Because I'm an idle git, I just bung a whole tablet in.

evanvine said:

You MUST add SO2 to get rid of the Chlorine compounds.

Click to expand...

Why MUST ?

When there are other ways to get rid of chlorine... such as boiling, etc...

Surely any method that works is fine ?


:

I agree strange; chlorine is a volatile compound which dissipates from H20 pretty quickly with either evaporation for a few hours or applied heat. Filtration is the quickest and easiest way, but it introduces a few issues. First of course the cost and replacement filters. Second you begin filtering other minerals from the water vital to yeast health and mash PH. For a beginner I'd just boil for a few min prior to making the wort.

Thanks for the replies... boiling sounds like the best way but I should have mentioned I'm only doing a partial boil (because I'm doing my boils stove-top and doubt I can keep the full volume at a rolling boil for an hour)...

So the other option would be measuring the additional water out the night before and leaving it.. thing that would worry me about that though is the chance of infection since I'm adding it post-boil.

I assume covering it and leaving it to sit in the FV would slow the dissipation of chlorine?

Boiling will get rid of the chlorine but not any chloramine your water company has added. For this you'll need a Camden tablet.

OK then... safest is to use half a campden tablet in case the smell I've getting is chloramine.
But still in the dark about how much sodium metabisulfite that translates to...

I googled some pictures of campden tab packets and one said it contained 550mg.
So if we're adding a half tab to 22L, for 12L it'd be 275mg.. roughly a quarter gram.

Sound about right?

keith1664 said:

Boiling will get rid of the chlorine but not any chloramine your water company has added. For this you'll need a Camden tablet.

Click to expand...

No comment re previous posts!

evanvine said:

keith1664 said:

Boiling will get rid of the chlorine but not any chloramine your water company has added. For this you'll need a Camden tablet.

Click to expand...

No comment re previous posts!

Click to expand...

The original poster asked about Chlorine, not Chloramine which not all water companies use but even then there is no MUST use a campden tablet as carbon filtration, ascorbic acid etc will also remove Chloramine.

:

daveozzz said:

OK then... safest is to use half a campden tablet in case the smell I've getting is chloramine.
But still in the dark about how much sodium metabisulfite that translates to...


Sound about right?

Click to expand...

The only thing I could find on the equivalents was...

"Campden tablets typically weigh 0.44 g each and 10 of these are equivalent to one level teaspoon of sodium metabisulfite"

So you need 1/20th of of a teaspoon ... however your going to measure that !

The bottom line is if your not actually getting any TCP like tastes in your beer you don't need to do anything ! I just leave my water to stand a little while before brewing and have never had a problem.

:

daveozzz said:

still in the dark about how much sodium metabisulfite that translates to...

Click to expand...

One Campden tablet in one gallon produces 50ppm sulphite

One campden table will neutralise 3ppm chlorine or mono chloramine in 17 UK gallons of water.

Is too much dangerous . . . Not really as sulphite acts as a reductone (helps prevent oxidation) . . . there is a rumor that it can contribute to sulphide production during fermentation (aka Burton Snatch) . . . but you have to have much higher quantities of sulphite for that to happen.

many water companies dose with chlorine only which can be removed by splashing it about when filling, or by heating the water up . . . However if that chlorine comes into contact with any ammonia in the pipeline it will form chloramine which is not removed by aeration or boiling (effectively), and you need an alternative method for removal.

GAC filters will adsorb chlorine and chloramine, but once the filter becomes saturated it has been known for the filter to dump what it has adsorbed back into the water! Also you don't get a lot use from a GAC filter for chloramine. The one I have is rated to 20,000 gallons for Chlorine, but only 2000Gallons for chloramine.

Apart from brewing at weekends I'm not to paranoid about using sulphite to remove chlorine (At the weekends its left on automatic, and the 'engineers' tend to tweak it to slightly over dose and you can smell it gassing off when you run the water into the sink). The vast majority of TCP tastes found in beer stem from bacterial infection caused by contamination and inadequate disinfecting of the brewing vessels. The other prime cause is that of not rinsing chlorine based cleanser sanitisers properly . . Here again a final sulphite rinse cane be a big help as it will neutralise any remaining chlorine.

StrangeBrew said:

The bottom line is if your not actually getting any TCP like tastes in your beer you don't need to do anything ! I just leave my water to stand a little while before brewing and have never had a problem.
:

Click to expand...

I agree... there's an awful lot of countermeasures you can take in brewing - generally I try not to bother with any of them until I find I have a problem that needs fixing.
Never had a TCP smell before.. but then again I've never smelt chlorine from my tap water until recently...

Hmm Perhaps I should just bang on and do a batch as normal and hopefully won't notice a difference.. otherwise I'll forever be attempting to measure 1/20th teaspoons of SO2 and not really know if it's actually helping or not!

Very informative replies though - thanks guys..

daveozzz said:

I'll forever be attempting to measure 1/20th teaspoons of SO2 and not really know if it's actually helping or not!

Click to expand...

Make a 10% solution 10ml of your 10% solution is the equivalent of 1 campden tablet 1ml - 1/10th of a campden tablet = 5ppm

Schimples Tchck

daveozzz said:

Hello,
I live not far outside Edinburgh and have never noticed a chlorine smell from my water before so never bothered treating it when brewing.. but just recently the water has started smelling quite strongly of chlorine for some reason.

So thinking I should sort that out before using for the next batch. I know most people use campden tabs... but I've got an unopened tub of sodium metabisulfite lying around which I know I could use instead, if I could work out how to measure the right amount..

So questions:

1. Can anyone tell me the rate of sodium metabisulfite to water I should be using? (have seen much speculation about this via google but little by way of consensus). I brew smaller batches than most btw - about 12L at a time.

2. Given the rate will likely be less than a gram.. any tips how to measure such a small amount? I thought about dissolving a gram in a set amount of water and then using an accurate syringe to dispense that (I have a 5ml syringe) - but then my brain started hurting trying to work it out.

3. Does it really matter being accurate - am I likely to ruin a batch by throwing in a good old pinch? Is too much bad?

4. Probably a stupid question, but do you only add it when the water is unadulterated? You can't add it to the wort?

Cheers for any help!
D.

Click to expand...

I'm relatively new to brewing, I brew in Sheffield which has chlorine in the water (took couple of brews to work out it's the water and not me) I now use sodium metabisulphate, I purchased it online thinking it would come in tablet form now stuck with 100g powdered form.
I just measure 1 gram and add to 20L of water which works, and I'm not dead so you'll be fine just adding a pinch. I'm sure someone will ridicule me for doing it that way but there we go.

@original poster. Use .5gram for 10l batches and you'll be on the money

I just used 1/2 gram for a 25 litre batch so a quarter should do you.
I have a set of scales that measure from 0.01g upwards.

daveozzz said:

Hello,
I live not far outside Edinburgh and have never noticed a chlorine smell from my water before so never bothered treating it when brewing.. but just recently the water has started smelling quite strongly of chlorine for some reason.

So thinking I should sort that out before using for the next batch. I know most people use campden tabs... but I've got an unopened tub of sodium metabisulfite lying around which I know I could use instead, if I could work out how to measure the right amount..

So questions:

1. Can anyone tell me the rate of sodium metabisulfite to water I should be using? (have seen much speculation about this via google but little by way of consensus). I brew smaller batches than most btw - about 12L at a time.

2. Given the rate will likely be less than a gram.. any tips how to measure such a small amount? I thought about dissolving a gram in a set amount of water and then using an accurate syringe to dispense that (I have a 5ml syringe) - but then my brain started hurting trying to work it out.

3. Does it really matter being accurate - am I likely to ruin a batch by throwing in a good old pinch? Is too much bad?

4. Probably a stupid question, but do you only add it when the water is unadulterated? You can't add it to the wort?

Cheers for any help!
D.

Click to expand...

Yeah. Treat your water. Chlorine will boil off (waste of energy) but chloramine won't. Metabisulfite will remove both. I use a good pinch per 10 litres of water. About a quarter of a Campden tablet would be much more than enough, but you can't overdose at these levels. Then a stir, the effect is almost instantaneous.
If you forgot, you could try adding it to the unhopped wort, it certainly won't do any harm.

pmh said:

I'm relatively new to brewing, I brew in Sheffield which has chlorine in the water (took couple of brews to work out it's the water and not me) I now use sodium metabisulphate, I purchased it online thinking it would come in tablet form now stuck with 100g powdered form.
I just measure 1 gram and add to 20L of water which works, and I'm not dead so you'll be fine just adding a pinch. I'm sure someone will ridicule me for doing it that way but there we go.

Click to expand...

That's the way I do it. After all the boiling, it ends up by adding a tiny amount of sulphate to your water. It won't kill you, they add it to wine as an antioxidant.

Would boiling evaporate the chlorine since the chlorine would have reacted with the water to produce HOCl and HCl? Boiling may lead to reactions with the boiling vessel and further oxychlorides such as HClO3.