Coca Cola Water Treatment?

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matt76

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Bear with me here, daft idea maybe, but I Googled this and didn't find much info and, well, I'm curious

I had a Coke at lunchtime - and you know that thing about "if you leave a tooth in a glass of Coke overnight..." well it's not exactly a secret it's quite acidic...

Anyway, I grabbed my pH meter, I measured about 2.75! I was surprised it was as low as that!

Now i don't know exactly what is the pH of the lactic acid or CRS I use normally as part of my water treatment. And also I understand that when we add acids to our mash water we're not really changing the pH - but somehow, once we add the grain we've magically given the mash pH a nudge in the right direction.

But it got me thinking, what would happen if I was to add, say, the contents of a 330ml can of Coke to my 15L mash water (about 2% by volume) instead of 5ml lactic acid or 10-15ml CRS?

(N.B. I brew small 10-12Lish batches, BIAB, full-volume no-sparge mash)

- I might have done it wrong but an online calculator I tried told me 15L water + 330ml Coke @ pH 2.75 would give me pH 4.4
- We'd be adding some sugar presumably - but don't some folks do that for some beers anyway? Albeit late in the boil I believe rather than in the mash? Never done it myself, but I'd expect a drier finish???
- Also some flavourings... Hmm...
- And we're adding a bit of colour... I'd guess fairly dilute/subtle though...

Anyone want to have a go at speculating what the outcome might be and whether there's any mileage in it? Not that we don't already have good methods for water treatment, but experimenting can be fun too...
 

GerritT

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Bear with me here, daft idea maybe, but I Googled this and didn't find much info and, well, I'm curious

I had a Coke at lunchtime - and you know that thing about "if you leave a tooth in a glass of Coke overnight..." well it's not exactly a secret it's quite acidic...

Anyway, I grabbed my pH meter, I measured about 2.75! I was surprised it was as low as that!

Now i don't know exactly what is the pH of the lactic acid or CRS I use normally as part of my water treatment. And also I understand that when we add acids to our mash water we're not really changing the pH - but somehow, once we add the grain we've magically given the mash pH a nudge in the right direction.

But it got me thinking, what would happen if I was to add, say, the contents of a 330ml can of Coke to my 15L mash water (about 2% by volume) instead of 5ml lactic acid or 10-15ml CRS?

(N.B. I brew small 10-12Lish batches, BIAB, full-volume no-sparge mash)

- I might have done it wrong but an online calculator I tried told me 15L water + 330ml Coke @ pH 2.75 would give me pH 4.4
- We'd be adding some sugar presumably - but don't some folks do that for some beers anyway? Albeit late in the boil I believe rather than in the mash? Never done it myself, but I'd expect a drier finish???
- Also some flavourings... Hmm...
- And we're adding a bit of colour... I'd guess fairly dilute/subtle though...

Anyone want to have a go at speculating what the outcome might be and whether there's any mileage in it? Not that we don't already have good methods for water treatment, but experimenting can be fun too...
Interesting thought experiment. The amount of sugar in a can would be in the 30-35 gram range (hardly noticable, if), colouring and taste come mostly from caramel and flavouring.
Which reminds me, I have a bottle of Pepsi in the fridge, and some pH-strips. Maybe a good Sunday morning activity :)

Found it:

Ingredients
 

matt76

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Ah, interesting and so obvious - I hadn't thought of the stated ingredients...

Coke UK website gives those ingredients exactly as you list them, specifically listing sugar (I think it would be chosen syrup in the US though).

I'm intrigued by the mention of phosphoric acid though - I'm sure I've read some people use it for water treatment anyway.

Oh, and it says 10.6g sugar per 100ml, so 35g per 330ml can.
 

Pennine

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take it easy on the number of cokes you use or else you'll end up with a diesel.
 

Pennine

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also try the pH when its flat. supposedly it will drop even more.
 

matt76

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also try the pH when its flat. supposedly it will drop even more.
Good point.

Actually the meter was jumping around between 2.7-2.8, I assume because of the bubbles...

But I think you're right that carbonic acid (a.k.a. fizzy water) is acidic, although fairly weak IIRC.
 

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