Water chemistry Primer questions/advice - Page 24 - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > Brew Science > Water chemistry Primer questions/advice

Reply
 
Thread Tools
Old 09-01-2011, 07:46 PM   #231
-TH-
Recipes 
 
Oct 2008
Zeeland, Michigan
Posts: 903
Liked 90 Times on 53 Posts


AJ, how many minutes have you seen it take for a mash pH to stabilize?
__________________
TH

Builds, etc: E-Brewery | Pneumatic Bottle Capper | Fermentation Chamber | Stirplate | Bottle Cabinet
Water Spreadsheet: www.EZWaterCalculator.com

 
Reply With Quote
Old 09-01-2011, 09:54 PM   #232
ajdelange
HBT_LIFETIMESUPPORTER.png
Recipes 
 
Aug 2010
McLean/Ogden, Virginia/Quebec
Posts: 9,025
Liked 1400 Times on 1067 Posts


Hard question to answer as pH changes continuously throughout the mashing process. The only time one really has to wait, in my experience, is when sauermalz is used. The pH can be alarmingly low at a first measurement but then drifts upward at a pretty good rate. After 10 minutes it will have increased dramatically. After 15 it should be close enough to it's "final" value that you could consider that an appropriate time to determine whether you have hit your target or not. Beyond 20 min it shouldn't change much.

If CaCO3 is used I'd expect equally long, or longer stabilization times but then I never use CaCO3 so I haven't much experience with that.

 
Reply With Quote
Old 09-01-2011, 11:26 PM   #233
emjay
Recipes 
 
Jan 2011
Toronto, Ontario
Posts: 12,794
Liked 1719 Times on 1606 Posts


I'm surprised to hear that about sauermalz. I would have expected pH to be a bit high at first, and then drift downwards.

And why does CaCO3 take a long time? Is it just the poor solubility?

I just moved, so I have yet to brew a batch where I intentionally adjust pH. I have a gallon of Five Star 75% phosphoric acid, and also a small container of calcium hydroxide (for raising pH) that I bought in a Tamil grocery store, of all places. While looking for a specific ingredient for a beer I was planning, no less. No idea what they use it for (the owner took another little container and just showed me that he gets a bit on his finger and puts it on his tongue!), but it's clearly food-grade.

One thing I'm wondering though is that, even though the CaOH is a powder, the ingredients list says it contains both calcium hydroxide AND water. Is there a typical hydrate or something, or am I going to have to perform a titration to figure out what I'm working with?

 
Reply With Quote
Old 09-02-2011, 01:09 AM   #234
ajdelange
HBT_LIFETIMESUPPORTER.png
Recipes 
 
Aug 2010
McLean/Ogden, Virginia/Quebec
Posts: 9,025
Liked 1400 Times on 1067 Posts


I'm guessing that the lactic acid is quickly "washed" off the surface of the malt thus acidifying the liquor but takes time to penetrate into the grist where it reacts with the buffers in the malt.

Yes, calcium carbonate reacts slowly unless the pH is very low. IOW, if you put it in a beaker and pour strong mineral acid over it it will fizz giving off carbon dioxide. If you put it in water and bubble CO2 through the water it will take seemingly forever to dissolve.

Ca(OH)2 is used in western food preparation to offset acidity especially in the making if pickles.

Don't think slaked lime (calcium hydroxide) has water of hydration but if it is exposed to humid air it will, as will most substances, adsorb some water. It's probably not enough that it needs to be accounted for except in the most precise work.

 
Reply With Quote
Old 10-04-2011, 07:38 PM   #235
pickles
 
pickles's Avatar
Recipes 
 
Feb 2008
Columbus
Posts: 2,007
Liked 49 Times on 41 Posts


Quote:
Originally Posted by ajdelange View Post
A way around the lag question is to make a test mash - i.e. scale everything down to about a pound of grist and check the pH. If it doesn't come in right adjust the acid and try again. You will then know what to do for the main mash.
When doing this test is it appropriate to scale the mash water quantity down as well or is it irrelevant? Also, should it be mashed at the actual mash temp for the desired recipe?
__________________
Gaptooth Brewhouse

 
Reply With Quote
Old 10-04-2011, 07:53 PM   #236
ajdelange
HBT_LIFETIMESUPPORTER.png
Recipes 
 
Aug 2010
McLean/Ogden, Virginia/Quebec
Posts: 9,025
Liked 1400 Times on 1067 Posts


Yes (it's relevant though mash pH is not strongly dependent on amount of water) and yes, test mash should be doughed in at the strike temperature you plan to use though the sample of liquid on which the pH is measured should be cooled to room temperature.

 
Reply With Quote
Old 10-05-2011, 02:20 PM   #237
jmf143
Recipes 
 
May 2010
Wixom, Michigan
Posts: 609
Liked 21 Times on 19 Posts


Quote:
Originally Posted by ajdelange View Post
Yes (it's relevant though mash pH is not strongly dependent on amount of water) and yes, test mash should be doughed in at the strike temperature you plan to use though the sample of liquid on which the pH is measured should be cooled to room temperature.
What if you re using an ice bath to cool the sample and wait too long i.e. it cools to 40 - 50 degrees? Will the pH measurement still be accurate?
__________________
Vir sapit qui pauca loquitur

 
Reply With Quote
Old 10-05-2011, 04:36 PM   #238
ajdelange
HBT_LIFETIMESUPPORTER.png
Recipes 
 
Aug 2010
McLean/Ogden, Virginia/Quebec
Posts: 9,025
Liked 1400 Times on 1067 Posts


No, the pH will continue increase as the temperature decreases.

 
Reply With Quote
Old 08-29-2015, 12:30 AM   #239
J_MAR
Recipes 
 
May 2013
New Braunfels, TX - Texas
Posts: 7


Quote:
Originally Posted by -TH- View Post
Did you put it in the EZ 2.0? I've had pretty good luck with it so far.

I know for beers with SRM > about 40 things get skewed and I am working on that.
,





Quote:
Originally Posted by SC_Ryan View Post
So 0.4g of Chalk or 0.28g of pickling lime is potentially enough to move the mash pH from 5.2 to 5.4? That seems like very little. Is it that much per gallon?

 
Reply With Quote
Old 09-04-2015, 03:09 PM   #240
TastyAdventure
Recipes 
 
Sep 2013
Posts: 668
Liked 44 Times on 38 Posts


Hey guys, I'm about to brew an Octoberfest Ale and have been reading that soft water is important for this style. All I have ever really done before in the past is adjust for mash pH and add some calcium chloride (per this website: http://www.brewersfriend.com/mash-ch...er-calculator/ ) to as close to what they call a "Balanced profile"

Anyways, here's my water stats. How can I make my water softer?
Alkalinity: 73
Calcium: 48
Mag: 7
Sodium: 33
Sulfate: 74
Bicarbonate: 73
Chloride: 38
Hardness: 144

Thanks!

 
Reply With Quote


Reply
Thread Tools



Forum Jump