Mash pH questions.

HomeBrewTalk.com - Beer, Wine, Mead, & Cider Brewing Discussion Community.

Help Support Homebrew Talk:

interplexr

Well-Known Member
Joined
Feb 22, 2010
Messages
72
Reaction score
2
Location
Lynchburg, VA
My water is very soft. Ca - 6ppm, Mg - < 1ppm, Na - 7ppm, SO4 - 3ppm, Cl - 4ppm, HCO3 - 12ppm.

I've been adding CaCl and MgSO4 to my mashes lately to try and bring up my Ca and Mg levels. I use EZWater to determine the amounts I want.

My question revolves around measuring my mash pH and how much effect that has on my efficiency. I've been using beermaking test pH strips. (4.6 - 6.2) Whether I make a water modification or don't, I can't get any reading on those test strips. I dip them in my mash at various times but I always get the same color as befor I even dipped it in. I dip the strip in for 1-2 seconds then pull and try to read. The only time I've gotten any kind of reading was when I dumped some baking soda in the mash. I got it to read then. Could my pH be lower than 4.6? What effect on my efficiency am I getting. It's all over the map which I'm hoping is more just my inexperience and making attempts at different techniques and whatnot as I learn.

I've currently trying my hand a hefeweizens. I've been anywhere from 50% eff. to 75%. I'd like to know if my pH issues could play into this much. I'm hoping that my decoction methods or choice of mash times and temps are to blame. ;)

What do you folks think? I appreciate the help ya'll have given me so far.
 
Joined
Aug 28, 2009
Messages
2,714
Reaction score
135
Location
Raleigh
I would think that with such low alkalinity buffer it is possible you are getting very acidic mashes. How acidic would depend on the amount of dark vs pale malts in your grain bill. The more dark malts you have, the more acidic the mash. I would imagine that an all-base-grain bill would be OK in terms of acidity and may give you better efficiencies. Including malts that have been roasted longer will drop the pH of the mash and if you don't have the proper residual alkalinity to buffer against this drop, the mash pH will fall below the range favorable for starch conversion. If it is too acidic your efficiency will indeed suffer as the beta-amylase enzyme will not be acting in it's working range (alpha amylase works at an even higher pH). Your best bet is to do as you indicated in the past, add baking soda to the mash to boost your alkalinity buffer.
 
OP
I

interplexr

Well-Known Member
Joined
Feb 22, 2010
Messages
72
Reaction score
2
Location
Lynchburg, VA
Would adding baking soda not cause my color to be darker? I've been trying to get very light colors for the hefe's as well as the other things I've tried. I'm looking for SRM 2-7 or so.
 

remilard

Well-Known Member
Joined
Nov 19, 2008
Messages
3,654
Reaction score
53
Location
Kansas City
With that water your pH is very close to 5.8 with an all pilsner malt beer.

No, your mash pH is not below 4.6 unless you are mashing all roasted barley or something like that.
 
OP
I

interplexr

Well-Known Member
Joined
Feb 22, 2010
Messages
72
Reaction score
2
Location
Lynchburg, VA
I've been using pilsner and wheat for the hefe and the previous batches used mostly pale malt. I agree that my pH should be higher but according to those little strips it just doesn't register. I want to say it's a bad batch but I don't have a good way to say that. I know if I add baking soda they will get dark but thats it.
 
Joined
Aug 28, 2009
Messages
2,714
Reaction score
135
Location
Raleigh
For these lighter beers I would think you are fine without adding baking soda. If you do start using darker roasts you will want to add an alkalinity buffer.
 
OP
I

interplexr

Well-Known Member
Joined
Feb 22, 2010
Messages
72
Reaction score
2
Location
Lynchburg, VA
When should you take a pH reading of your mash? Should it be taken righ at the beginning or after some time has passed?
 

maida7

Well-Known Member
Joined
Nov 10, 2009
Messages
2,827
Reaction score
50
Location
Asheville, NC
I'm having the same issue as the OP. I just brewed a very pale beer (pilsner) and I used salts to adjust my residual alkalinity. My mash PH was crazy low. Like 4.6 ish. Efficiency was around 70% so maybe it is not such a big deal.

What effect does having a low mash PH? I assume it would effect the efficiency and conversion but what else? Will it effect the flavor of the beer? Yeast health? Fermentability?
 
Top