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Increase pH in mash

mgranath

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Hi

My water is totaly useless for brewing, so I use deionized water and the add the salts in the mash. The problem is that the deionized water gets a bit acidic really fast. Therfore I exaggerate the addition of CaCO3, but I don't know how to calculate it. The acid calculator in BS is really good but wouldn't it be nice to have a calculator for increase of the pH?
 
I use RO/DI water for all my brews and don't have an issue unless brewing a stout or something with lots of heavy roast malts. I'm curious how much of an issue you're having?

also, for reference i've only had a couple times i've needed to increase PH and have used slaked lime in VERY minimal additions. like 2g in a 25 Gallon batch
 
CaCO3 has very low solubility.  You are better off using baking soda to balance out pH and supply carbonates to the water.
 
mgranath said:
The problem is that the deionized water gets a bit acidic really fast.

The acidity is because the water absorbs CO2 from the atmosphere. I'm betting that it settles around 5.8 pH. This isn't a problem and can be ignored because it has nothing to do with buffering malt.

You can do a quick test of this with a few ounces of crushed pale malt. Wet it with an equal weight of heated water and leave it for 10 minutes. You should see close to 5.5 pH. It will vary a bit depending on which pale malt you use, how old it is and when it was crushed.
 
You're spot on my PH of RO/DI water, generally its between 5.83-5.9 for me, and my Mash PH is usually spot on around 5.3 for MOST mashes, although i've had a few closer to 5.5-5.6 and some down around 5.2 my lowest mash was 5.11 which i brought up with a touch of slaked lime because i didn't have any dissolved CaCO3 on hand at the time.
 
Here's the recipe on my chocolate dubbel. The pH in the mash was 4.9 with a calibrated pH meter.
http://beersmithrecipes.com/viewrecipe/2066003?&doid=5c420f239b943
 
Not too much of a surprise.  First, the chalk is not very soluble as I pointed out above and 15 grams for a 5 gallon recipe is an awful lot.  Solubility of chalk without bubbling CO2 through the water is around 15 mg/L at 25C, so you only saw about 0.5 to 0.6 grams of that actually dissolving in the water at best.  At what point did you add the Carafa Special to the wort?  If it was during the mash then this would add a lot of acidity to the wort. 

Also, I think your SRM value for the Carafa Special is the color of the Carafa Special III not the Special II as you have listed.
 
Oginme said:
Not too much of a surprise.  First, the chalk is not very soluble as I pointed out above and 15 grams for a 5 gallon recipe is an awful lot.  Solubility of chalk without bubbling CO2 through the water is around 15 mg/L at 25C, so you only saw about 0.5 to 0.6 grams of that actually dissolving in the water at best. 

At what point did you add the Carafa Special to the wort?  If it was during the mash then this would add a lot of acidity to the wort. 

Also, I think your SRM value for the Carafa Special is the color of the Carafa Special III not the Special II as you have listed.

I added all the salts in the mash. Is chalk difficult to solve even if I add it to the mash?

I added the Carafa wort in the main wort after the mashing.

According to Weyermann it is the right color: https://www.weyermann.de/usa/gelbe_Seiten_usa.asp?snr=1&idkat=1303&umenue=yes&idmenue=269&sprache=10

Anyway, I haven't experimented so much with water additives during the 15 years I've brewed. Therefore I'll immerse myself more in this subject now.
 
Responding to your points/questions in order:

Chalk is naturally difficult to dissolve having a low solubility in water.  It is also inversely soluble with temperature, meaning that as temperature increases the solubility decreases.  Calcium carbonate (Chalk) is commonly used as filler pigments in paper, paints, and coatings due to its low solubility and whitening/opacifying properties.  It is also the main constituent in the formation of stalactites and stalagmites in caves as the slow dissolving of the chalk and quick deposition from evaporating water helps to form these structures.  Part of the formation is also due to high levels of Carbon dioxide dissolved in the water which increases the solubility of the chalk.  For this reason, the only feasible way to add Calcium carbonate is to infuse the water with Carbon dioxide.  Again, this solubility has limits. 

Did you take the pH reading before or after the addition of the steeped Carafa?

Weyermann lists the range of color for Carafa Special II at 415 - 452 SRM.  Carafa Special III is listed at 491 - 566 SRM.  In your recipe, the color for the Carafa Special II is listed as 583.8 SRM.

A good source to look for on water chemistry is Martin Brungard's treatise on 'Water Knowledge' which I have attached for you.

 

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  • Water Knowledge by Martin Brungard.docx
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I'll add to Oginme's post this bit from braukaisers site about Chalk in brewing, as it really helped me understand it. I'd also recommend picking up the book "water" which is the last(?) book in the four book series on brewing ingredients (See also: hops, malt, yeast)

http://braukaiser.com/wiki/index.php/Building_brewing_water_with_dissolved_chalk

additionally, I also see the carafa II in your recipe listed at the color of carafa III
 
Slaked lime also raises pH and gives yeast and kettle reactions a great boost with the calcium. It's much more soluble than chalk; about the same as gypsum in my experience.

Cheers,

Mark
 
Thanks for all your answers and tips! I now must go deeper into water chemistry, it's interesting!
 
Download a copy of Bru'n water. Voila. Problem solved. I know its not ideal to use two brewing programs but the water calculations on beersmith just aren't very accurate. I use uit more as a recipe database for all of my recipes. Also, the starting pH of your water is irrelevant and won't have an effect on the outcome of the mash if you've accounted for grain acidity contributions. Use Bru'n water and you'll see.

Cheers,

Mark
 
The water calculations on BeerSmith actually agree quite well with Bru'n water.  Are you actually referring to the mash pH calculations?  There is an easy work around if you find that the acid recommendations are off for you which is to change the % acid in the lactic or phosphoric acid (which ever you are using) to bring it in line with your actual needs.  Beyond that, I have found that both programs (and others I have tested) seem to have their own foibles which must be taken into account.  For my process and starting materials, I find a consistent offset in predicted pH using BeerSmith which I can then use to reach the actual target I am looking for.  I have documented this in other message threads if you have an interest in searching. 
 
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