Water help

Physics, chemistry and biology of brewing. The causes and the effects.

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Water help

Postby Freon12 » Wed Mar 13, 2002 2:56 pm

What are the methods for mash PH adjustment between a very pale beer and an amber one? I usually start with water that has a PH of 7.8 and very hard water,and if the beer has any dark malts I usually end up at 5.7. I try to adjust the mash to below 6 with lactic acid(also the sparge with lactic to 5.3), but sometimes I get a lactic after taste on a young beer that fades with age. I trying to round off the edges of an ALT, but it falls in the middle of dark and light malts for PH reaction. This beer should not be grainy or harsh in any way due to the single 60 min. hop addition. Any help?
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Phosphoric Acid

Postby BillyBock » Wed Mar 13, 2002 3:28 pm

You mention your water is hard, so I assume you don't use gypsum or calcium chloride to adjust the mash pH. Not knowing your water chemistry, I'd suggest those first. Otherwise, have you considered phosphoric acid? I've heard that it's preferable to lactic acid. I personally use lactic only because that's what I can get @ the LHBS.
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restart H2O

Postby Fraoch » Thu Mar 14, 2002 1:48 am

Why not boil your water for 15mins the night before and allow to cool over night. The chalk will precipitatye out of solution and sink to the bottom allowing you to rack off soft water from above. This can then be modified with Gypsum etc to whatever the requirements of the style of beer. Saves blasting the buffering effects in your water with L.acid to adjust PH.
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Boiling and Hardness Precipitation....

Postby Mesa Maltworks » Thu Mar 14, 2002 7:02 am

The suggested technique of boiling water and cooling prior to brew day is a ggod idea as it will precipitate a PORTION of the precipitate load. BUT... only the temporary hardness elements, not those permanantly entrained in the water. Depending on the local water chemistry of the postor, this may or may not be enough. This technique does NOT render water to a "soft" condition. There will still be a good portion of minerals left behind. The use of phosphoric acid improves the hardness break when using this technique without any other water quality effect (unless overused !). To go through this process and then add gypsum or epsom salts (known as "Burtonizing") makes no sense at all since their use ELEVATES hardness and sulfate concentration and would obviously be counterproductive.

For those who like to know the technical details of what is at work here, read below:

Water is composed of ions with negative (anions) and positive (cations)charges. The water molecules (H2O) themselves are also partially dissociated into hydroxide (OH-) and hydrogen (H+) ions, and the pH, or percent Hydrogen, indicates the relative concentrations of these ions. Neutral water has OH- and H+ concentrations of 0.1 ppm, which corresponds to a pH of 7. Lower pH values indicate a higher H+ concentration and a higher acidity, while higher pH values correspond to a higher OH- concentration and a higher alkalinity. In brewing, the pH is determined by the hardness, alkalinity and buffering salts derived from the ingredients.

Alkalinity refers tp the capacity of the dissolved anions to neutralize reductions in the pH value of the solution. The most important anion at the pH of brewing water and wort is bicarbonate (HCO2)-, which reacts with Calcium (Ca+2) ions when heated to form a calcium carbonate precipitate and water:

Ca+2 + 2(HCO2)- = Ca2CO3 (ppt) + H2O + CO2 (gas)

This removes Calcium ions from the water, reducing the temporary hardness. Permanent hardness is a measure of the cations that remain after boiling and racking the water from the precipitate, and is primarily due to Ca+2 and
Magnesium (Mg+2) ions. These cations are permanent if they are derived from sulfate or chloride salts and temporary if they originate in carbonate or bicarbonate salts.

An important process in brewing that helps adjust the pH of the mash is the enzymatic degradation of phytin in the malt which forms phytic acid and magnesium or calcium phosphates, which will precipitate. Most of the phytic acid combines with free Ca+2 to form more calcium phosphate, causing the release of hydrogen ions. This reaction generally takes place during the acid rest, making the mash pH fall within the 5.2-5.7 range, which is facilitates the breakdown of starches and proteins. Some waters are too high in alkalinity for this process to be effective, so the pH must be reduced by adding lactic or sulfuric or phosphoric acid. I prefer phosphoric over sulfuric due to safety and storage concerns and over lactic due to higher dosages required and flavor problems in the final product.

The most important cation in brewing is Calcium, due to it being required to reduce the mash pH to the appropriate range, retaining oxalate salts in solution (they form haze and gushing if they precipitate), reduces the extraction of tannins, and assists in protein coagulation in the hot and cold breaks. Magnesium ions participate the same way, but are not as effective. Yeasts require 10-20 ppm as a nutrient, but higher amounts give a harsh, mineral-like taste. Another important cation is Sodium, which will accentuate the perception of sweetness at low levels, but will result in a salty flavor at higher concentrations.

The most important anion in brewing is carbonate, which neutralizes acids from dark and roasted malts, co-reacts with Calcium to reduce hardness and accentuates the extraction of tannins and color extraction. It is normally in solution with the carbonate (CO3)-2 ion, but the carbonate is by far the most important component at typical pH values of water and wort. The sulfate (SO4)-2 ion does not play a significant role in the brewing process, but accents hop bitterness and dryness such as with the high concentrations found in the waters at Burton-on-Trent. (ie... why adding gypsum or epsom salts is called "Burtonizing". Another anion is chloride (Cl-), which enhances sweetness at low concentrations, but high levels can hamper yeast flocculation.
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Boil

Postby Freon12 » Thu Mar 14, 2002 7:52 am

I do boil the water and sometimes cut it down with bottled water. Based on what I read below, I think the problem lies with the Lactic acid, and I will try phosphoric for the sparge water. This should move me to the next lighter beer from Brown. Thanks for the reply. Dortmunder export coming this way!
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Dilution is SOMETIMES the solution....

Postby Mesa Maltworks » Thu Mar 14, 2002 12:00 pm

Regarding the dilution of brewing water with bottled water... remember... most bottled water is HIGH IN SULFATES and a lot of bottled water, particularly that labled "spring" or "mineral" water is also very hard ! If you want to dilute, use distilled water. This water is devoid of mineral content and therefore is very "soft". Another bonus is that newly opened distilled water does not have to be boiled as it is essentially sterile as is. Sulfates, however, can still be an issue depending on the pre-distillate water source.

And an aside... I really only feel it is necessary to adjust your water for a very narrow group of styles that would otherwise not taste even close to the specifications. One such style category is the Bohemian Pilsner style (Czech) which uses incredibly soft water. The other Pilsner styles use water that is MUCH harder.

A personal opion/aside: Since water makes up the largest portion of ingredients in beer, it is also one of the greatest sources of unique advantages to differentiate your brews from that made by others. If you always adjust your water to some "idealized" standard, you may miss out on a pleasant experience. In my opion, the only reasons to adjust water is to increase potability (ie... filtration or de-mineralization (like iron & sulfur)and decrease pH for mashing or if like the Pils example, there is no other way to get a particular attribute that definitively defines a style.
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Charactor

Postby Freon12 » Fri Mar 15, 2002 1:49 pm

Yes of course you are correct. The only reason I am adjusting water is because the end results of tannins and other unwanted sharp or enhanced tastes exist in some but not all of the beers I have made with this water. I only want to do the minimum to the water because it is basically good.(and hard) Maybe, I'm being too picky for a homebrewer because none of the beers are bad so to speak.
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ever tried acid malt?

Postby mvoigt » Mon Jun 12, 2006 12:08 pm

I use acid malt to lower the PH of my wort. I do not treat my sparge water for PH. for my local water i use .75 ounces of acid malt per every pound of grain in the mash. this lowers the PH from 7.0. to about 5.3. any sever incorrect thinking on my part?
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