Free BJCP Prep Course: Class 5 -Water

Your water source is drinkable?

• remove chlorine: boiling of off-gassing(sit overnight)
• remove chloramine: charcoal filteration or campden tablet(1 tablet/20gal)
• reverse osmosis(RO)=all minerals stripped out
• BJCP states RO or deionized water<mineral or spring water

Alkalinity, pH, hardness?

• water=negative anion(hydroxide OH-)+positive cation(hydrogen H+)
• pH=the concentration of hydrogen ions(H+)
• eg. pH 7 means: same amount of H+ and OH-
• higher concentration of hydrogen(H+) ions=lower pH(acidic)
• higher concentration of hydroxide(OH-) ions=higher pH(alkaline/basic)
• alkalinity is a measure of the capacity of the dissolved anion(eg. HCO3-, bicarbonate)
• bicarbonate(HCO3^-)+calcium(Ca²⁺)=calcium carbonate precipitate+water+carbon dioxide
• means reducing amount of bicarbonate=reducing alkalinity
• permanent hardness: remaining cations after precipitate(eg. Ca²⁺, Mg²⁺)
• these are permanent: from sulfate or chloride salts
• these are temporal: from carbonate or bicarbonate salts <- after boiling, it remove 

Why pH and minerals so important?

• an enzymatic degradation of phytin->form of phytic acid(storage of phosphates)->release phosphates->combine w/ calcium or magnesium->calcium(magnesium) phosphate+hydrogen(H+) ion->optimal pH!(5.2~5.7)=mash with excellent efficiency
• if your water have too much alkalinity: 
• add gypsum salt or epsom salt
• add phosphoric acid or lactic acid(short cut)

Important ions in brewing water

• cations
• calcium 
• essential for reducing pH
• keep oxalate salt(clarity)
• reduce tannin
• aids protein coagulation(precipitation)
• magnesium
• less effective than calcium
• put too much, harsh mineral taste
• sodium: sweet. put too much, salty
• anions
• bicarbonate(HCO3^-)
• determine alkalinity
• neutralize acid from dark/roasted malt
• increase tannin and color(darker) <- brighter beer=acidic water
• sulfate(SO4^-2): bitterness and dryness
• chloride(Cl^-): sweetness(at lower level). put too much, hamper flocculation

Related fault

• sulfur like: check ion content if not a lager
• metallic: check high ion content
• harshly bitter: check sulfate level
• overly malty: check chloride level
• salty: check sodium content or add too much salt?

Water chemistry

Alkalinity

• alkalinity will effect mash pH
• mash pH will effect: 
• enzyme activity
• yeast acitivity
• beer pH
• tannin extraction
• Residual alkalinity is a measure of the buffering effect of water
• alkalinity is caused by carbonates(CO3--, from the ground), CO2(from the air)
• expressed as ppm CaCO3

Hardness

• hardness is a measure of ions, Ca and Mg ions present in the water
• expressed as CaCO3(Calcium carbonate)
• hardness=50*([Ca]20+[Mg]/12.1) *Mg's influence is half of Ca's
• alkalinity generally bad, hardness reduce alkalinity, hardness is good for brewing
• hard water can be manipulated by the brewer(to achieve desired characteristics we want in our beer, or simply mash pH)

Residual Alkalinity

• RA is the buffering effect of the water/ after Ca&Mg react with phosphates in the malt(to reduce alkalinity)
• if RA is too high, need to adjust the mash(add more hardness or acidify)

Water composition

• potable(safe to drink) water generally suitable for brewing
• except for Chlorine
• activated carbon is used to remove chlorine(&stabilizer)
• especially when you sanitize the brewing water with chlorine
• sulfate(SO4--): 

1. large effect on hop usage(bitterness)
2. more assertive hop character
3. increase bitter linger time
4. too many sulfates bring low quality bitterness=astringent(>300mg/L)
5. concentration should be in the range 0~250mg/L

• Sodium: 

1. can sweeten the malt character at low amounts
2. leads to salty taste in high concentrations
3. concentration should be <50mg/L

• Chlorides: (vs. sulfate)

1. salty taste in high concentration, pasty in very high(>300mg/L)
2. round, sweet quality to malts in modest amounts(bad for hop aroma)
3. concentration should be 0~100mg/L

• Iron: 

1. the less is better, tinny and inky, metallic character
2. concentration when brewing should be Nil(zero content)

• Copper: 

1. metallic taste, indicate pipe corrosion
2. need a small amount for yeast enzyme cofactor 
3. concentration should be <1mg/L

How to understand the water report

• Calcium improves beer clarity, increase yeast flocculation, protect enzyme from heat
• the equation for calculating RA(as CaCO3 in mg/L, like alkalinity): 
• RA=total alkalinity-[Ca]/1.4-[Mg]/1.7  
• Kolbach's rule: link 
• also, what's Kolbach index: link
• mEq/L RA=mEq/L alkalinity-[mEq/L Ca]/3.5-[mEq/L Mg]/7 *mEq/L=milliequivalents per liter 

Adjusting water

• adding sulfates and chlorides should be the first step
• sulfates: chlorides ratio effects taste
• up to 9:1 for really hoppy beer(safer to stick around 4:1)
• 1:2 for malty beer
• calcium sulfate(gypsum salt)
• calcium chloride
• magnesium sulfate(epsom salt)
• magnesium chloride
• now your mash pH reaches 5.3? 
• acid can be used to lower mash pH if the RA is too high
• phosphoric acid(H3PO4)
• citric acid(C6H8O7)
• and lactic acid

article summary: the principles of pH

source: https://byo.com/malt/item/1494-the-principles-of-ph

pH change that happens during the mashing

• mashing=precipitation of phosphates(found in brewing water)+amino acids derived(taken) from the malt
• phosphoric acid(H3PO4) disassociate
• (if calcium ions are present)calcium phosphate disassociate, leaving behind hydrogen ions
• higher(than 10^-7mol/L) H+ concentration in a solution=acidic link
• (if magnesium ions are present)magnesium phosphate do the same thing, but the effect on pH is less dramatic
• if calcium sulfate is added, the calcium ions react with the amino acid group(present within the solution)then leave behind hydrogen ions
• these changes in mineral composition+the precipitation of calcium salts->pH decrease(prior to fermentation)
• the carbonate(CO3-2), bicarbonate(HCO3-) ions act as buffers to pH decrease

Proper mash pH

• optimal pH of an infusion mash: 5.2~5.6
• high pH during the mash increase the amount of dextrins, less fermentable wort
• polyphenols(such as tannins), silica compounds easily extracted under high pH: instability, astringency*
• *when sparging, pH of the last running climbs to 5.8~6.0, stop the sparging

Controlling Mash pH

• with lots of carbonate ions in the water(high mash pH): 
• add calcium ions from gypsum(calcium sulfate) or calcium chloride
• or add organic acids(phosphoric acid, lactic acid)
• if a brewer is using very soft water(low mash pH):
• add a little bit of chalk(calcium carbonate), baking soda(sodium bicarbonate)
• link Understanding residual alkalinity&pH

The importance of boil pH

• during the boil, calcium phosphate continue to be precipitated
• optimal post-boil wort pH: 5.0~5.2
• Maillard reactions are not favored at lower pH(for light colored beer)
• to lower pH, add a little bit of calcium(gypsum, calcium chloride, acid)

Fermentation

• optimal ending pH less than 4.4(larger 4.2~4.6, ale 3.8)
• during fermentation, pH continue to drop: 
• yeast take in ammonium ions(strongly basic) and excrete organic acids

other helpful articles

Residual Alkalinity and pH for All Grain Beer Brewing

Effective hardness=Ca(ppm)/1.4+Mg(ppm)/1.7

RA=Alkalinity(as CaCO3)-Effective hardness or (50*Bicarbonate)/61-Effective hardness

Residual alkalinity and mash pH

full size Residual Alkalinity Nomograph link

pH stories

Here is a fun article about making 'glowing sushi' with a glowing protein, called GFP.

article

ok, then what about the glowing beer? Is it possible to brew the glowing beer with the yeast where GFP can be activated? According to the article, the answer is no. Because the glowing protein actually is dependent on pH conditions, and a majority of target pH of finish products is below pH 3~4 where there is no way to activate for GFP.
Then, why does pH condition go down during beer fermentation? I googled.

1.
(from there)
Fermentation is the oxidation of organic carbohydrates(means starch) under anaerobic(means no oxygen) conditions.  The classic example is the fermentation of sugars into ethanol and carbon dioxide utilizing yeast for beer and wine production. During this process, CO2 is released into the air in the form of gas bubbles.  But much CO2 is also dissolved in the water solution.  CO2 dissolved in water produces carbonic acid (H2CO3) in small quantities according to the equation below:

H2O + CO2 --> H2CO3

Carbonic acid is a weak acid that will lower the pH slightly.  So this is why the pH changes slightly during fermentation.

2.
(from there)
Substantial factor:

• Organic acid excreation(means separated from a bigger body)
• Absorption of basic amino acid(basic blocks that comprise proteins, from malted grains*)

Less extent factor:

• Solution of carbon dioxide
• Absorption of primary phosphate(PO3-4)

* leave it for smarter future me... 

What is free amino nitrogen(FAN) link

amino acid link

3.

(from there)

• pH affects the shape of proteins.
• (If pH is increased, this affects the shape of proteins, by disrupting bonds in the protein.)
• Enzymes are responsible for the metabolic processes that occur. 
• Enzymes are proteins. 
• Enzymes work best in acidic condition, when pH is lower, which bend the protein into the correct shape to allow fermentation to occur. 

conclusion: lower pH is good for your wort. 

4.

and the good basic lesson about pH for homebrewers is here

leave it for the future me, too.

Yeast cells take in ammonium ions (which are strongly basic, similar to alkaline) and excrete organic acids (including lactic acid)