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Old 10-18-2010, 03:00 PM   #1
Beerrific
 
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I brewed a porter this weekend. First time I have ever used a pH meter to measure the mash pH. Thought I would share the results.

Original water (ppm):
Ca: 4
Mg: 1
Alkalinity as CaCO3: 22

In 5 gallons of mash water I adjusted to:
(Added 3g of CaCl2)
Ca: 47
Mg: 1
Alkalinity as CaCO3: 22

This gives an RA of -14.

Two commonly used water chemistry guides:
Palmer:
Using Morey this is a 31 SRM beer. Plamer calls for an RA of 256 to 315. To get the low end you would need 8g of baking soda in the mash.

Tasty Brew 2.0:
15.5 lbs total grain, 2.5lbs specialty non-roasted, 1.25lbs roasted. 31 SRM. Predicts a mash pH of 4.96 and I would need 8g of baking soda in the mash to get a pH of 5.2 which is my target.

Both those leave me with about 73ppm of sodium in the final beer. So not bad, below the threshold for a salty taste. I am lucky I have <10ppm Na in my tap water. If I did not have a pH meter, I could probably add this and not worry too much.

Actual brew day:
dough in, pH: 5.15
add 2g baking soda, pH 5.27
I let it sit for 5 minutes and checked it again: 5.24 and this is where it stayed for the length of the mash.

So a RA of 25 is sufficient for brewing a 31 SRM beer. I know others have said they have done similar things, but I guess it is nice to confirm this myself. I hesitate to draw any other conclusions from this being that it was just 1 sample. But, I am going to really try to take the mash pH for every beer from now on.

 
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Old 10-18-2010, 05:12 PM   #2
wildwest450
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I checked mine for the first time this weekend. The ez water calculator estimated the ph @ 5.25, my new meter read 5.3, kinda cool.

 
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Old 10-18-2010, 05:27 PM   #3
motobrewer
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interesting. so what would a RA of 287 do? i'm brewing a porter this weekend and my tap has a RA of 287

 
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Old 10-18-2010, 05:52 PM   #4
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Quote:
Originally Posted by motobrewer View Post
interesting. so what would a RA of 287 do? i'm brewing a porter this weekend and my tap has a RA of 287
If you plug your water numbers into the ez water spread sheet it will give you an approx ph, then you can do salt additions if necessary.

 
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Old 10-19-2010, 12:37 PM   #5
ajdelange
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Quote:
Originally Posted by Beerrific View Post
dough in, pH: 5.15
add 2g baking soda, pH 5.27
I let it sit for 5 minutes and checked it again: 5.24 and this is where it stayed for the length of the mash

So a RA of 25 is sufficient for brewing a 31 SRM beer.
And for a 4 SRM beer and a 84 SRM beer. There is really very little connection between color and RA. As you are now checking mash pH you can pretty much forget that you ever heard that the 2 are correlated (they are, of course, but it shouldn't affect the way you brew).

As you seem concerned about increased sodium in your beer let me suggest that instead of increasing mash pH with sodium bicarbonate you use calcium carbonate or calcium hydroxide (pickling lime) as the source of alkalinity. In either case you do the same thing - sprinkle the dose onto the mash, mix in thoroughly, wait a few minutes and then measure pH. Calcium carbonate is probably the most commonly used for this purpose because it is found in every LHBS. It works but slowly because it is insoluble and, according to Kai's experiments, not completely for that same reason. Lime, OTOH, is quite soluble and should, thus, work as fast as the sodium bicarbonate. It can be obtained in the canning department of most large supermarkets. In either case you are increasing desirable calcium rather than undesirable sodium in the course of adjusting mash pH.



Quote:
Originally Posted by Beerrific View Post
I hesitate to draw any other conclusions from this being that it was just 1 sample. But, I am going to really try to take the mash pH for every beer from now on.
Just write your obervations in your brewing log and draw conclusions when you have accumulated a number of them. What you saw seems completely normal to me.

 
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Old 10-19-2010, 01:24 PM   #6
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Quote:
Originally Posted by ajdelange View Post

As you seem concerned about increased sodium in your beer let me suggest that instead of increasing mash pH with sodium bicarbonate you use calcium carbonate or calcium hydroxide (pickling lime)...
At what point should i start worry about the sodium? With 2g in the mash and none in the sparge that leaves something like 24ppm before the boil. From this experience I doubt I will ever need much more than 2g. I have some pickling lime in the closet, maybe I will try that next time.

 
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Old 10-19-2010, 01:40 PM   #7
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Quote:
Originally Posted by ajdelange View Post
And for a 4 SRM beer and a 84 SRM beer. There is really very little connection between color and RA. As you are now checking mash pH you can pretty much forget that you ever heard that the 2 are correlated (they are, of course, but it shouldn't affect the way you brew).
BTW Kai found that: "the specific acidity (titratable acidity per kg of malt) of crystal malts increases at a slope of about 0.13 mEqkg-1EBC-1 (r2= 0.77), [and] roasted malts have a specific acidity of about 40 mEqkg-1 regardless of their color." (see: http://braukaiser.com/documents/effe...on_mash_pH.pdf Sections 3.3 - 3.5 PLEASE READ).

The reason I mention this is to point out that the EZ 2.0 asks for SRM (and % of malt types) for the purpose of figuring out the breakdown of the grist - i.e. how much (and what color) is crystal, how much roasted, etc., so it can then, based on kai's experiments, estimate mash pH. It does not necessarily use SRM to make a direct correlation to RA as a whole.

Quote:
Originally Posted by ajdelange View Post
Just write your obervations in your brewing log and draw conclusions when you have accumulated a number of them.
AJ, I presume that by now you have made a substantial number of entries in your brewing log. Any chance you would be able to share some of your data with me?
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Old 10-19-2010, 01:42 PM   #8
ajdelange
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Quote:
Originally Posted by Beerrific View Post
At what point should i start worry about the sodium? With 2g in the mash and none in the sparge that leaves something like 24ppm before the boil. From this experience I doubt I will ever need much more than 2g. I have some pickling lime in the closet, maybe I will try that next time.
Unless your doctor has told you to avoid sodium then you should start worrying about it when you find the beer tastes of it more than you want it to. I often suggest people dissolve a little sodium bicarbonate in a glass of water to get a feel for what it tastes like. When you use sodium bicarbonate to set mash pH most of the bicarbonate turns into CO2 and escapes but not all of it. At pH5 4% remains; at pH 5.2, 6%; at pH 5.4, 9.5% and so on. If you use chalk (calcium carbonate), the same thing happens but you wind up with less residual at a given pH because it takes half as many CO3-- ions as HCO3- ions to neutralize the same amount of acid (and you get the secondary benefit of beneficial calcium instead of useless sodium as the cation). If you use lime (Ca(OH)2), there is no residual bicarbonate (the product of the neutralization is water) and you get calcium as the anion.

Now some authors feel that some residual bicarbonate is important in some beers. For example, Daryl Richman in his monograph on Bock beer recommends it.

Once you get the mash pH under control by proper use of a pH meter, salts, acids and grains (the science part) , the rest of the job is tuning for taste - the artsy part.

 
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Old 10-19-2010, 01:47 PM   #9
cheezydemon3
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Awesome thread. This PH problem with dark grains is amplified in PM brews.

Having gone back to PM's I put baking soda in any dark brew.

I believe this is the source of the extract TWANG myself, which I have eliminated.

 
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Old 10-19-2010, 02:47 PM   #10
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Quote:
Originally Posted by cheezydemon3 View Post
Awesome thread. This PH problem with dark grains is amplified in PM brews.
PM?

Post modern?

Phase modulated?

Beers brewed in the afternoon?

TH: Haven't forgotten about you. Just haven't gotten around to it.

 
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