Mash Ph

[Keifer]

I did a basic AG on the weekend and got a ph of 3.9, how will this affect my brew, palmer says a high alkalinity may extract tannins but does not say what a high acidity will do..

Here's what i used by the way:
0.25kg wheat malt
0.5kg pale crystal
5kg jw traditional ale
normal tap water

also i cleaned the HLT and copper mash manifold with vinegar before hand, rinsed well but maybe not well enough?

 

[Stuster]

It must have been the vinegar, but even then it would take a fair amount of it to make your mash that acidic. Since the ph scale is logarithmic, that pH is nearly 20 times more acidic than it should be. There's nothing in your grain bill that would cause such a low pH. I can't find a reference now, but I think I read that a low pH can lead to an acrid taste. :unsure:

 

[DJR]

What was the efficiency? Might have been a bad reading, acidity will affect the enzyme efficiency in the mash but i can't think of what else it will affect. You might end up with a very acidic beer that yeast doesn't want to grow in very well if that was the real pH. At least you'll have no problem with infection

 

[sah]

Wow apprentice, that is acidic! What is the pH of your brewing water before adding to the mash tun? It'd have to be very low to start with. I would think well below 7. Probably enough to corrode copper pipes.

Do you suffer from heart burn? :blink:

regards
Scott

 

[Adamt]

How did you measure your pH? It may be time for a re-calibration.

 

[KillerRx4]

How should PH be measured? Does heat have an effect?

I ventured into ph adjustment last brew. I measured the water pre mash @ strike temp & also pre sparge @ sparge temp. I added a little Citric acid to get it down from ~6 - 7 to ~5.*

But at the time i considered maybe heat will make a difference to measured ph.

btw i used ph paper for measuring.

 

[sah]

I don't think heat makes a difference to the pH. It might make a difference to the instrument you use to measure it?

The pH you need to be concerned about isn't that of your water, its that of your mash. The water pH is generally in the 7 to 8 range, when you mash-in the pH will come down hopefully to the 5 to 6 range. Anyway the point is if you are going to test the pH test the pH of the mash.

regards
Scott

 

[barneyhanway]

I too have too low ph - my water starts off below 7 and my mash ph falls off the bottom of my spa pool test strip range (have to get some paper in the correct range!)
so, I know you can add various types of acid to add to water to lower ph, what do you generally add to raise it?

 

[DJR]

Chalk (calcium carbonate) raises mash pH... there is a good section on it at howtobrew.com.

 

[Keifer]

I have a digital ph meter, not yet calibrated and only used a couple of times but my water reads just less than 7. It was indeed the mash ph i was testing and did so multiple times.

My efficiency turned out to be 62% and no i don't have heart burn

 

[Norsman]

I currently us citric acid to get my pH down as I have the opposite problem with high alkalinity (pH 8.6). I have found a little bit goes an encredibly long way in dropping th pH. I have found my self adding more water to bring the pH back up on occasion.

I have a question though, goes gypsum (calcium suphate) help to reduce the mash pH??

 

[Stuster]

Norsman, gypsum will lower ph in the mash. The articles and calculators on this page should give you a start on brewing water chemistry.

 

[crells]

A ph of 3.9 sounds a bit unbelievable to me. I say calibrate your ph meter, and if does not have ATC adjust the temp first. Also make sure you are only measuring liquid (no/minimal grain bits in sample).

 

[lonte]

Might as well add my couple of questions here ...

Given that conversion is "so quick" with today's highly modified malts (I've heard the bulk of the mash can be over in as little as 10 minutes) how do you measure and adjust the pH quickly enough for it to make an effect on the mash? I am creeping up on 5.2 by adding 1ml phosphoric more each time I brew lately (all pale-ish beers of late) but the next brew is a stout and I understand that all grain bills are different (especially all those dark grains) and so there'll be no magic number of ml that will cover all mashes.

Also, what effect do the grain "bits" in the sample have?

 

[Ash in Perth]

temperature has a fairly significant affect on pH, just attemperate your samples to room temp before measuring and that should be accurate enoguh.