Chloramine + Ascorbic Acid / Vitamin C Questions

I've never had noticable issue with Chloramines but I know my water company uses them and the levels they use can vary, so I picked up some Vitamin C / Ascorbic Acid to treat my water. From what I've read, a quarter of one tablet at the dosage I bought will do the job for my typical 5 gallon batches. Seems like it would be a couple of cents well spent.

Hope someone can clarify a few couple of things, though.

Sometimes, especially when I brew with extract, I'll top off at the end of the boil with a gallon or so of tap water. Will the Ascorbic added to the pot at the beginning of brew day still work on the new addition of water? Or will the heat (or something in the wort) have broken down the Ascorbic acid and will I need to re-treat the new water before topping off?

Also, I've found a number of places regarding the chloramines warning Vitamin C "degrades in a day or two which only make it usable for short-term applications" with the implication that the chloramines will return. I assume that's bogus, right?

It's used to neutralize Chlorine and Chloramine by a lot of people who raise fish -- this document from the Forest Service states "Once it is placed in solution, however, vitamin C degrades in a day or two" but the document also goes on to recommend its use as a dechlorinator for water for fish.

www.fs.fed.us/t-d/pubs/html/05231301/05231301.html

I assume the reference to degrading over a couple of days is just a warning that you can't add new water with chlorine or chloramine to a batch of water treated with Vitamin C a couple of days in the past. But I can't imagine someone would put a thousand dollars worth of fish into water that would kill them in day or two, right?

While I'm at it, I assume there's nothing in particular to consider otherwise, right? Everything I've read says at the amounts I'm looking at, there's no meaningful change in PH, the only inactive ingredient listed is cellulose and that can't be more than a few mgs per batch at any rate.

Vitamin C is an antioxidant/reducing agent, which is how it neutralizes the (oxidizing agent) chloramines. Anything left is going to react with the oxygen in air over time.

The risk would be that once the chloramines are gone, if there is anything in the water (residual organics, etc.) that critters could eat, they may colonize your water after a while. That is a pretty minor concern especially if you're going to boil that water.

I wasn't going to calculate it, but the pedant in me said to put down the beer and do some logarithms. 1000 mg of ascorbic acid is quite a bit...it will drop 19 L (5 gal) of distilled water to a pH about 3.9. I don't know what the typical residual of chloramine is, but at 10 ppm (which seems really high!), 1000 mg ascorbic acid is enough to treat 1500 liters. You could probably get away with a 10th of a tablet.

Thanks for the reply.

>Vitamin C is an antioxidant/reducing agent, which is how it
>neutralizes the (oxidizing agent) chloramines. Anything left is
>going to react with the oxygen in air over time.

>The risk would be that once the chloramines are gone, if
>there is anything in the water (residual organics, etc.) that
>critters could eat, they may colonize your water after a while.
>That is a pretty minor concern especially if you're going to boil
>that water.

What I was wondering about was the odds of the chloramines or related compounds reforming over time, although I wasn't too concerned -- the sites I saw which warned of such a thing seemed to be kind of loopy water treatment government conspiracy types. From what you're saying, it sounds like these ideas are about as reliable as the General in Dr. Strangelove, and I assume if fish owners use it, then it's fine, since those people need to be even more careful than brewers.

I am curious about the effect of heat on the vitamin C treatment, if you have any idea, though. If I top off with fresh tap water after an hour long boil, do I need to treat the fresh water? I'm not a chemist, but it seems at least feasible that the ascorbic acid breaks down or reacts to something during the boil. But, I never know until the end how much I need to add, and measuring out the right amount of ascorbic for top off water of 1.33 gals or .75 gal or whatever starts seeming like a pain. Although maybe at those volumes, the amount of new chloramine is too low to worry about....

> I wasn't going to calculate it, but the pedant in me said to
> put down the beer and do some logarithms. 1000 mg of
> ascorbic acid is quite a bit...it will drop 19 L (5 gal) of distilled
> water to a pH about 3.9. I don't know what the typical
> residual of chloramine is, but at 10 ppm (which seems really
> high!), 1000 mg ascorbic acid is enough to treat 1500 liters.
> You could probably get away with a 10th of a tablet.

My back of the envelope calculations were this: My tablets are 500 mg. I read that 1000 was enough for a 60 gallon bathtub, so one of my tabs would be good for 30, and a quarter would be good for about 7.5 gallons, which is close enough to what I start with. That means I'd be adding about 125 mg, which is pretty close to what you recommend. Maybe I'll scale things down just a touch, if I can manage it at these tiny quantities.

midlantic said:

From what you're saying, it sounds like these ideas are about as reliable as the General in Dr. Strangelove, and I assume if fish owners use it, then it's fine, since those people need to be even more careful than brewers.

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I don't care if their fish die. I do care about what can live in my beer. I want the yeast to live, for a while, and everything else to die.

midlantic said:

Thanks for the reply.

What I was wondering about was the odds of the chloramines or related compounds reforming over time,
...
I am curious about the effect of heat on the vitamin C treatment
...
Although maybe at those volumes, the amount of new chloramine is too low to worry about....

Click to expand...

The chloramines won't come back.

The heat will destroy the vitamin C. That's why they say vegetables are most nutritious with minimal cooking.

You could boil or treat some water and keep it sealed in sanitized gallon containers, or use water from the store. We normally use jugs of spring water for *all* brew water, which is kind of pricey but I haven't gone to the effort of setting up dechlorination. I don't have anything big enough to conveniently handle 20 gallons of water anyway.

The reaction between chloramine and ascorbic acid is
NH2Cl +( )(OH)2 ---> NH4+ + Cl- +( )(O)2

The empty parentheses, ( ), represent everything in ascorbic acid except the two hydroxyl groups opposite to the O in the lactone ring. Thus what is left over is ammonium ion (yeast nutrient) and chloride ion (both of which are produced when metabite is used to reduce chlorine) plus dehydroascorbic acid rather than the sulfate ion which is produced when metabite is used. It's this stuff that I am a bit skeptical of as it can, for example, degrade valine to isobutyraldehyde and, in the presence of metal ions become an oxidizing agent. So while it is probably OK in the amounts involved I am a little nervous about it in the mashtun, fermenter and finished beer but I'll note that ascorbic acid has been used to stabilize beer though it is usually mixed with metabite to keep the dehydroascorbic acid from oxidizing further.

Another thing that bothers me a bit about ascorbic acid is that it is a strong acid (pK1 = 4.10) and quite soluble in water (330 g/L). It's interesting stuff in that it can either give up the two hydrogens in those OH groups with their electrons in a redox reaction (as they do when reducing chloramine) in which case there is no pH effect, or without their electrons in which case it is an acid/base reaction and there is a pH effect. The bottom line is that if you dose in extra ascorbic acid (more than will be oxidized by the chloramine) the remainder will give up protons and the pH will fall so you have to be more careful with dosing than you would with bisulfite.

Given that, why not use metabite? It is readily available either in the form of Campden tablets or as powdered sodium or potassium salts from wine making suppliers.

I've added ascorbic acid dosing information and some of these remarks to the Campden Tablet sticky.

ajdelange wrote:

> Another thing that bothers me a bit about ascorbic acid is that it is
> a strong acid (pK1 = 4.10) and quite soluble in water (330 g/L). It's
> interesting stuff in that it can either give up the two hydrogens in
> those OH groups with their electrons in a redox reaction (as they do
> when reducing chloramine) in which case there is no pH effect, or
> without their electrons in which case it is an acid/base reaction and
> there is a pH effect. The bottom line is that if you dose in extra
> ascorbic acid (more than will be oxidized by the chloramine) the
> remainder will give up protons and the pH will fall so you have to be
> more careful with dosing than you would with bisulfite.

Wow, that's great detail, although I have to admit that the chemistry is beyond me.

On a related note, one thing that occured to me regarding Vitamin C is that a lot of fruit beers must contain quite a bit. Some quick Googling leads me to think that recipes calling for pounds of cherries or raspberries or whatever must add a lot more Ascorbic acid than the 100 mg recommended for dealing with Chloramine when making a 5 gallon recipe. Also, people add a gallon of cider treated with Ascorbic acid to apple ales, and of course people make hard cider out of sweet cider treated with Vitamin C.

I'm guessing the effect differs on when the fruit is added -- I've seen recipes out there which add it to the pot right away when the heat is first turned on; at flameout; in a secondary fermenter; and even at bottling time. I'm sure it's also partly a function of what else is in the recipe.

Given your concerns above, do you have any input on what effect Vitamin C may have on fruit beers, and any best practices for when to add fruit?

I always advocate checking mash pH (and wort and beer) pH with a good meter. If you do this you will know whether you must make adjustments for fruit acidity (be it from ascorbic or citric or another acid). If you are going to brew beers with fruit that means you have accepted any risk associated with the effects of dehydroascorbic acid (if there even are any) but its an unknown world, at least to me, and so I suppose it's a good idea to be aware of these things. I'd try to find brewers that are experience in using fruit in their beers. That's not me.

ajdelange said:

I always advocate checking mash pH (and wort and beer) pH with a good meter. If you do this you will know whether you must make adjustments for fruit acidity (be it from ascorbic or citric or another acid). If you are going to brew beers with fruit that means you have accepted any risk associated with the effects of dehydroascorbic acid (if there even are any) but its an unknown world, at least to me, and so I suppose it's a good idea to be aware of these things. I'd try to find brewers that are experience in using fruit in their beers. That's not me.

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I ferment low to get rid of fruity esters as it is. Fruit in beer almost always sounds better than my taste buds judge it.