Water Flashcards
Temporary hardness
-Carbonate & bicarbonate salts of calcium and magnesium can be boiled out
-Will raise pH
Permanent hardness
-Non-carbonate salts eg sulphates, chlorides, nitrates cannot be boiled out
-Will decrease pH
Removing temporary hardness
-Can be boiled out, but leaves scaling
-Lime/calcium hydroxide additions + bicarbonates = calcium carbonate–will precipitate out!
-OR Acid treatments to release co2 and form calcium salts
Removing permanent hardness
-Ion exchange
–anion and cation exchange sites
-Reverse osmosis
–concentrates dissolved materials on one side up to 98%
Filtration/clarification
Removal of suspended solids
(Filtration) Screening
Filter through metal grills/screens to filter out larger or smaller particles, depending on mesh size
(Filtration) Coagulation and sedimentation
Chemical coagulants reduce time for solids to coagulate or flocculate out
(Filtration) Sand filtration
Removes turbidity, algae, microorganisms
(Filtration) Cartridge filtration
Polymer fibers wound into a spiral that traps particles. Used for water with low levels of suspended solids.
(Filtration) Membrane filtration
Semi-permeable membrane:
1. Microfiltration
2. Ultrafiltration
3. Nanofiltration
4. Reverse osmosis
Microfiltration
Removes down to 0.1µm
-Yeast, solids, colloids, most bacteria
Ultrafiltration
Removes down to 0.01µm
-Most viruses, colloids, large organics
Nanofiltration
Removes down to 0.001µm
-Most organics, salts
Reverse osmosis
Removes to 0.0001µm
-Most dissolved ions and molecules
Carbon filtration/Activated charcoal
Removes chlorine and most organic contaminants
-Organic halogenated compounds can affect color and taint flavor/aroma
(Sterilization) Chlorine Dioxide
Neutral, no flavor taints, non-corrosive, non-toxic, residual cleaning power
Ozone
3 oxygen atoms injected into the water
-Oxidizes bacteria cell membranes
-Decomposes into normal O2 ~10 min
-No off flavors
-Highly aggressive to rubber (eg gaskets)
UV Light
200-280 nanometer destroys the DNA of microbial contaminants
-Non corrosive, no flavor taints, no residue
-Must be treated immediately at point of use, sterilization only occurs at point of irradiation
Sterile filtration
Removes particles down to .1µm, includes bacteria and yeast
-no flavor taints, but filter can easily become blocked
Calcium effect on beer quality
+ Decreases wort pH, improves trub formation, aids yeast flocculation
- Low pH decreases extraction of hop bittering compounds
Magnesium
+ Decreases wort pH slightly & a little bit helps with trub formation and yeast flocculation
- Laxative effects, lol
Sodium
+ Low levels contribute to a full and sweet mouthfeel
- High levels give salty/sour taste
Sulphate
+ Emphasize hop character and dryness
- Too much = astringent & unpleasant bitterness. Precursor to sulphury off flavors
Chloride
+ Helps give body/fullness, and sweetness, emphasizes MALT character
- Too much can inhibit yeast growth and give a salty taste
Zinc
+ Vital yeast nutrient at low levels
- Toxic to yeast at high levels, also astringent
Iron/Manganese
+ nothin’
- Oxidization catalyst: Inhibits yeast activity and gives a metallic flavor :/
Carbonates/Bicarbonates
+ Increase pH, good if using dark malts
- High levels will increase ph, cause scaling on heating surfaces
Water profile: Pilsner type lagers
-Soft water, low mineral content
-Sulphates = chlorides (balance)
-Low calcium ion level for pH
Water profile: Ales (bitters, pales)
-Sulphates > chlorides (support bitterness)
-Low carbonates (balance the colored malts which lower pH)
-High calcium to reduce pH and balance the carbonates
Water profile: Milds, stouts, porters
-Chlorides > Sulphates (fullness and sweetness)
-Mid level carbonates to balance high color malt
-Calcium to help balance the carbonates and drop pH
