How important is the PH?

[the red devil]

Just fininshed my 3rd AG yesterday. Grain volume was over 6kg, so a big beer! Thought i'd done everthing right this time (learning from the threads on this site) when blow me if i didn't see something new on the brewday threads, PH
Now, i live in a hard water area so decided to use bottled water. The PH on the bottle was 7.4, seemed OK to me Then i saw on the thread that you should be aiming for a mash PH of 5.4ish
How important is this and what are the effects on getting it wrong?

[SiHoltye]

I found listening to this useful http://media.libsyn.com/media/basicbrew ... -11-07.mp3
It's covered in his book too http://www.howtobrew.com/section3/chapter15.html
Lot's of other authors cover this as well, it's just I had these to hand.

[agentgonzo]

As with a lot of things, you can still make pretty good beer by completely ignoring it. You can make even better beer by paying attention to it. The pH of the mash is important, not the pH of the water that goes into the mash as the grist and ion content of the water affects the final pH. I tend to not bother and make some damn good beer. I could probably make better beer and achieve better efficiencies if I paid attention to pH but don't bother.

[mysterio]

Dont worry. The water ph is completely unrelated to the mash ph. After you've mashed in, given everything a good mix, the ph will drop to around that range. Get yourself some ph strips, and test the mash liquor if you're worried. Most water is fine to brew with as-is, but you should make adjustments if it's much outside the 5.2 - 5.4 range.

I'm lazy and use the 5.2 buffer salts.

[confused]

to date I have done nothing to my water other than add a campden tablet. all through my "kit life" and now in the AG era I have been very happy with the products of my brewing.

I did start looking at water quality a couple of weeks ago, it gave me a bigger headache than a night on my "owd thumpa" barley wine. So it's back to the campden tablet for me and I'll remain satisfied with what I'm brewing. I think the biggest area may be efficiency - perhaps I am not extracting as much of the sugar during the mash as I could, but I am a bear of little brain, and will accept my limitations.

[Aleman]

Water pH is of b*gger all importance, mash pH is relevant but not critical although a lot is said that it must be 5.3 that is an optimum for the amylase complex . . . the individual enzymes have their own pH optima (5.0 for Beta and 5.7 for alpha IIRC) . . . but they will work outside these optima and normally quite effectively. My IRS had a mash pH of around 4.8, and that converted fine, and although the pH was better for beta amylase I haven't ended up with a thin beer there is still plenty of body in it.

it really starts to come into its own when you have really got the brewing process cracked, and are consistently turning out good beers . . . . then you start identifying very minor flaws, and its these that can be 'improved' with fiddling with these less important factors . . . like mash pH, water chemistry, liquor/grist ratios etc

[the red devil]

OK, theres some very good answers to my question there, thanks all
So far i have had good results with efficiency so i'm guessing i must be hitting the mash PH window (ish).
i will get myself some PH papers, if only for interest until i'm more proficient in brewing.

[Madbrewer]

Ok my turn to chip in because I am clueless also, but (Aleman) it does sound like you know your onions (or ions) certainly more than me!

The John Palmer how to brew chapter has a pdf slide-rule on paper tool to work out what to add to get your ph correct. I live in a real hard water area. Hogs Back water supply expressed as Calcium 109 mg/l, Magnesium 4 mg/l &
Total hardness as Calcium Carbonate 289 mg/l.

So I mark 109 ppm on the Ca ppm scale, then 4 on the Mg scale and draw a line as stated by the JP chapter 15 documentation and it says my effective hardness is somewhere around 70-75

Then i put the total hardness as Calcuim Carbonate figure in the Alkalinity as CaCO3 scale and plot a course by joining the effective hardess to the CACo3 figure and seeing where it hits the SRM scale above. It says 27 SRM is the optimum colour to head for. Then I decide to see what I need to add to get a 12.5 SRM beer I plot that line through the effective hardness scale, line that up with Mg ppm and extend the line telling me i need 350 ppm calcium meaning i need to add 241 ppm - ??

Have I got this right, to make it more acidic/ lower PH I need to add more calcium? as that doesn't sound right to me

[Aleman]

Palmer certainly knows how to complicate things

The most important thing to know is what the alkalinity of the water is, reduce this to 50 or below and increase the calcium to 150-200ppm mash pH will be pretty much in the ball park.

Yes adding calcium (either as the sulphate or chloride) will reduce the pH of the mash (It raises the pH of the liquor but that's not important). Basically what happens in the mash is that phosphoric acid is released from the phytase reaction in the malt. The calcium binds with the phosphate and precipitates leaving free hydrogen ions floating around which cause the pH to fall. I've seen figures quoted that suggest increasing calcium to 300ppm that I have doubts about, but working it though as a theoretical exercise then your figure of 350 isn't too far off. .. . . . Having said that Fix has quoted a minimum calcium level of 60ppm . . . personally I think both are somewhat off . . . but then I often forget about adding the salts until its too late and I still get a good beer out of it . . . and that's with a calcium level around 16ppm