Magnesium Testing

(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
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crashmat
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Magnesium Testing

Post by crashmat » Wed May 17, 2017 8:45 pm

Severn Trent don't seem to give magnesium figures in their detailed water reports, so I dug out one of my old Salifert test kits but noticed that it is for testing marine water only. Has anybody had a go at 'marinising' their water (maybe by adding NaCl???) so that you can test it with one of these kits? And if you did would you get a sensible reading for mg?

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Eric
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Re: Magnesium Testing

Post by Eric » Thu May 18, 2017 12:41 am

Don't waste your time. Barley won't grow unless there is sufficient magnesium in the soil.

Magnesium is more soluble than calcium and finds its way into the finished beer in circumstances where calcium won't. Malt supplies many times more magnesium than it does calcium and makes any amount of it in water relatively insignificant.

Worry about magnesium only when there is little in your water supply or when brewing high gravity beers to support the yeast or when you desire its influence on flavour.
Without patience, life becomes difficult and the sooner it's finished, the better.

crashmat
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Re: Magnesium Testing

Post by crashmat » Thu May 18, 2017 6:49 am

And that's why I asked the question........I'm brewing an Imperial Stout and, as per my original post, the Severn Trent water supply report does not list the mg content. I'm not asking about whether I should worry about mg levels in my brewing, I'm asking whether I can measure it using a marine testing kit.

WallyBrew
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Re: Magnesium Testing

Post by WallyBrew » Thu May 18, 2017 8:56 am

I do not know which kit you are talking about but the magnesium content of sea water is much greater than in drinking water so the kit may be useless for low levels.

If you want to determine it you will need a total hardness testing kit (not the karbonate hardness one) and a calcium testing kit. Express both as calcium and multiply the difference by 0.6 to get magnesium. Doubt it will be better than =/- 100% of the real figure.

crashmat
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Re: Magnesium Testing

Post by crashmat » Thu May 18, 2017 12:08 pm

Makes sense.....I'll get a fresh water kit.

Haydnexport
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Re: Magnesium Testing

Post by Haydnexport » Thu May 18, 2017 10:04 pm

you might be better off sending a sample of your water for a proper analysis

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orlando
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Re: Magnesium Testing

Post by orlando » Fri May 19, 2017 8:31 am

Haydnexport wrote:you might be better off sending a sample of your water for a proper analysis

....to WallyBrew.
I am "The Little Red Brooster"

Fermenting:
Conditioning: Hazey Shade Of Winter, St. Petersburg (RIS)
Drinking: Kernel Bogey (India Porter), Mild Boys, Chocolate Girl
Up Next: Black Dog, London Calling, Gertcherbrewed, Autumn Almanac
Planning: Autumn drinking beer.

aamcle
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Re: Magnesium Testing

Post by aamcle » Fri May 19, 2017 9:25 am

just email them and ask!

aamcle

Haydnexport
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Re: Magnesium Testing

Post by Haydnexport » Sat May 20, 2017 5:58 pm

orlando wrote:
Haydnexport wrote:you might be better off sending a sample of your water for a proper analysis

....to WallyBrew.
Indeed , but i don't like naming people !

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orlando
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Re: Magnesium Testing

Post by orlando » Sun May 21, 2017 6:33 am

Haydnexport wrote:
orlando wrote:
Haydnexport wrote:you might be better off sending a sample of your water for a proper analysis

....to WallyBrew.
Indeed , but i don't like naming people !
It's not a secret. :D
I am "The Little Red Brooster"

Fermenting:
Conditioning: Hazey Shade Of Winter, St. Petersburg (RIS)
Drinking: Kernel Bogey (India Porter), Mild Boys, Chocolate Girl
Up Next: Black Dog, London Calling, Gertcherbrewed, Autumn Almanac
Planning: Autumn drinking beer.

RobP
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Re: Magnesium Testing

Post by RobP » Sun May 21, 2017 11:16 pm

If it's just for a one-off brew, and you think it's that important, the cheapest solution is to buy some cheap bottled water from a supermarket. The label tells you the quantities of ions in it.

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