Can alkalinity be too low?

(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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guypettigrew
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Can alkalinity be too low?

Post by guypettigrew » Thu Jan 10, 2019 4:56 pm

Getting ready to brew tomorrow.

The Wallybrew analysis reports my water as 204ppm alkalinity. Graham's water treatment calculator tell me 50l of water needs 50ml AMS to bring it down to 20ppm.

Adding 50 ml gave me an alkalinity (Salifert test) of 16ppm.

Does this matter? Should I add some more tap water to get it up to 20ppm?

Or should I have checked the alkalinity with the Salifert kit before doing anything else?

Thanks.

Guy

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Aleman
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Re: Can alkalinity be too low?

Post by Aleman » Fri Jan 11, 2019 9:05 am

Always add the acid in two lots .... 2/3 of the recomended amount, stir wait 5 minutes, test with Salifert ... Adjust final amount of acid to take into account the salifert reading.

Wallybrews test was a point in time, your water changes daily ... sometimes it's significant. Always test alkalinity before adding acid ... A £4 eBay Cheapy Chinese TDS meter will tell you if your water has changed 'significantly' and you need to do an alkalinity check, if you dn't want to test each time.

Carnot
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Re: Can alkalinity be too low?

Post by Carnot » Fri Jan 11, 2019 9:33 am

Guy,

I do not think 16ppm vs target of 20 ppm is going to make much difference. Test kits are never super accurate so your 16 might even be 14 or 18. When you are getting to the extreme end of the range it is always a little tricky. When you get to 20 ppm alkalinity there is not much alkalinity buffering left. Aleman's advice was spot on. Don't add all the acid in one slug. I would add 70% , then 20% and the final 10% would be for trimming. If the pH is about right - in the target range- I would run with what you have.

guypettigrew
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Re: Can alkalinity be too low?

Post by guypettigrew » Fri Jan 11, 2019 10:51 am

Thanks both

The mash has a pH of 5.4 at 15 minutes in. Reasonable.

The AMS will definitely be added in a couple of lots from now on.

Guy

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Jim
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Re: Can alkalinity be too low?

Post by Jim » Fri Jan 11, 2019 10:54 am

The last analysis of my water (a few years ago now) showed total alkalinity of 14mg/l; I don't have any problems with it, so I would reckon you'll be fine.
"Reality is that which, when you stop believing in it, doesn't go away" - Philip K. Dick

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