brewing chemistry - distilling school...brewing chemistry h 2 0: beer + life 1. universal solvent 2....
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THE CHEMISTRY OF FERMENTATION
BREWING
CHEMISTRY
THE CHEMISTRY OF FERMENTATION
BREWING
CHEMISTRY
What we will learn:
BASIC CHEMISTRY– ATOMS, CHEMICAL
BONDING, CHEMICAL EQUATIONS
CHEMICAL REACTION BASICS
WHY/HOW WATER IS SO IMPORTANT
pH
IONS
CARBOHYDRATES/PROTEINS/ENZYMES
MOLECULAR MOVEMENT
4 BASIC INGREDIENTS:
WATER - MALTED BARLEY - YEAST - HOPS
BREWING
CHEMISTRY
Atom– simplest unit of
matter
ATOMIC STRUCTURE
BREWING
CHEMISTRY
https://www.youtube.com/watch?v=BMIvWz-7GmU
ATOMIC STRUCTURE
BREWING
CHEMISTRY
ATOMIC STRUCTURE
BREWING
CHEMISTRY
H, N, C, O, Na, P, Ca, K, Mg
S, Cl, F, Zn, Cu, Fe, I, Hg, Br,
Pb
ATOMIC STRUCTURE
BREWING
CHEMISTRY
IONIC BONDS & IONS
BREWING
CHEMISTRY
COVALENT BONDS
BREWING
CHEMISTRY
COVALENT BONDS - NON-POLAR MOLECULES/POLAR MOLECULES
BREWING
CHEMISTRY
CHEMICAL BONDS AND ENERGY
BREWING
CHEMISTRY
WATER – H2O
BREWING
CHEMISTRY
WATER & HYDROGEN BONDS & IONS
BREWING
CHEMISTRY
H2O: charged molecule which can bond to many molecules
WATER & HYDROGEN BONDS & IONS
BREWING
CHEMISTRY
WATER & HYDROGEN BONDS & IONS
BREWING
CHEMISTRY
HYDROGEN BONDS
1. Are moderately strong
intermolecular bonds; they
serve as links between
molecules.
2. Help determine three-
dimensional shape
3. Forms liquid water
4. Considerable cohesion
which creates a very high
surface tension
5. Formed between POLAR
molecules– most molecules
are POLAR
6. Helps hold many natural
molecules together
WATER & HYDROGEN BONDS & IONS
BREWING
CHEMISTRY
HYDROGEN BONDS
-hold starch molecules together in barley seed: we break
them apart in the first part of the mashing/cooking process:
GELATINIZATION
WATER & HYDROGEN BONDS & IONS
BREWING
CHEMISTRY
HYDROGEN BONDS
DNA
Enzymes/Proteins
Ex- H-bonds hold starch molecules together in barley
seed: we break them apart in the first part of the
mashing/cooking process
4 BASIC INGREDIENTS:
WATER - MALTED BARLEY - YEAST - HOPS
BREWING
CHEMISTRY
WATER – THE UNIVERSAL SOLVENT
BREWING
CHEMISTRY
H20: beer + life
1. Universal solvent
2. Necessary for all life’s
chemical reactions
3. Chemical reaction
medium for:
a. Fermentation
b. All living cells
(yeasts)
4. Stable temperatures for
life (high E storage in H-
bonds later)
5. High surface tension and
cohesion– “sticky”
Q- type of bond?
WATER – THE UNIVERSAL SOLVENT
BREWING
CHEMISTRYH20 and BREWING
1. Universal solvent-
MASHING (breaking down
large sugar to small simple
sugars)
2. Chemical reaction
medium for Fermentation
3. Stable temperatures –
lots of E for mashing,
boiling.
4. Cleaning
5. Heating & Cooling
WATER – THE UNIVERSAL SOLVENT
BREWING
CHEMISTRY
Water for: CLEANING; HEATING and COOLING
Brewing LIQUOR-
mashing +
fermentation
WATER – THE UNIVERSAL SOLVENT
BREWING
CHEMISTRY
H20 AND MIXTURES
1. SOLUTION
2. COLLOID
3. SUSPENSION
CHEMICAL REACTIONS: HOW TO READ THIS SHTUFF
BREWING
CHEMISTRY
C6H1206 → C2H5O + CO2
C6H1206 + O2 → H2O + CO2
CHEMICAL REACTIONS
BREWING
CHEMISTRY2 MAJOR CHEMICAL RXN TYPES
1. Decomposition
2. Synthesis
*Energy and Chemical Rxns:
*Temperature and Chemical Rxns?
CHEMICAL REACTIONS
BREWING
CHEMISTRYLAWS OF THERMODYNAMICS
ACIDS AND BASES
BREWING
CHEMISTRY
ACIDS AND BASES
BREWING
CHEMISTRY
ACIDS AND BASES
BREWING
CHEMISTRY
Pure Water is neutral (7.0 on the pH scale) : neither an acid nor a base
Base- a chemical above 7.0 on the pH scale
Alkaline is the adjective for base
Acid- a chemical below 7.0 on the pH scale
Acidic is the adjective for acid
ACIDS AND BASES
BREWING
CHEMISTRY
The proper pH of solutions in the brewing process is vital for a quality product
For example in the Mashing Process, the mash should have a pH between 5.2 – 5.6
Improper pH can result in many problems, including the production of off-flavors,
which can ruin a batch of beer
ACIDS AND BASES
BREWING
CHEMISTRY
pH buffer: A chemical of the opposite pH.
Example—the mashing pH is too alkaline (greater than 5.6),
so you can add an acid to bring the pH back down into range.
BREWING BUFFERS:
Bicarbonate—increases pH
Phosphoric acid—decreases pH
IONS AND BEER
BREWING
CHEMISTRY
Ions: definition
Ions play important roles in living organisms, including yeasts.
They are important in overall health and chemical reactions the
organisms participate in.
Ions: electrolytes and salts
IONS AND BEER
BREWING
CHEMISTRY
Calcium (Ca2+) and Magnesium (Mg2+) are vital for normal and happy yeasts
Sometime these ions need to be added to the brewing water for happy yeasts
IONS AND BEER
BREWING
CHEMISTRY
Other Important Brewing Ions:
Ca+ -- Can also be used as an acidic buffer.
source: calcium chloride, calcium
carbonate, calcium sulfate
Na+ (sodium)– used as alkaline buffer
source: sodium bicarbonate
CO3- (Carbonate ion)– originates from CO2
from
yeast fermentation: can increase the pH
HCO3- (Bicarbonate ion)– also originates
from CO2 from yeast fermentation: can
increase the pH
Fe+ (Iron)– can be present in water from
pipes;
not good for brewing
IONS AND BEER
BREWING
CHEMISTRYHard and Soft Water
Hard water contains high ion content, like
Ca+
and Mg+
Soft water is the opposite: low ion content
IONS AND BEER
BREWING
CHEMISTRY
If water needs to be “adjusted” after
treating or purifying water, ions can be
added back for the best water for brewing.
Calcium sources:
Ca chloride hydrate
Ca dihydrate
Ca sulfate
Ca carbonate
(Ca levels for happy yeasts should be about
50ppm)
Magnesium source:
Mg sulfate (Epsom salts)
4 BASIC INGREDIENTS:
WATER - MALTED BARLEY - YEAST - HOPS
BREWING
CHEMISTRY
CARBOHYDRATES
BREWING
CHEMISTRY
Carbohydrates Primary Function:
ENERGY
We can get carbohydrates from fruits,
vegetables, pasta, cereal grains
Carbohydrates’ other function:
STRUCTURE
The most common structural
carbohydrate is cellulose.
Structural polysaccharides cannot be
broken down by most organisms for
energy
Structure for:
Seed hulls (coat) of cereal grains
Seed diagram
BREWING
CHEMISTRY
CARBOHYDRATES
Energy carbohydrates come in 2
forms:
1. Simple sugars (monosaccharides
and disaccharides):
-glucose
-lactose
-sucrose
-fructose
Beer Fermentation ss:
-glucose (mono-)
-maltose (di-)
-maltotriose (tri-)
2. Complex sugars (polysaccharides):
-starch-- which is many glucose
molecules bonded together
-cellulose (seed hulls)
glucose
starch
BREWING
CHEMISTRY
CARBOHYDRATES
Simple sugars that yeast can eat:
glucose
maltose
maltotriose
Simple sugar source: Conversion of
starch from barley grains by
mashing
Yeasts eat the simple sugars
from barley grains for ENERGY
and produce ethanol and
CO2 as by products.
yeast
barley
BREWING
CHEMISTRY
CARBOHYDRATES
The starch is too large of a
molecule for yeasts to eat…so the
starch in the barley grain has to be
broken down into “chewable”
simple sugars for the yeast.
The starch is broken down into
simple sugars in the Mashing
Process
Cereal grains like barley, are
seeds.
Seeds contain 3 primary parts:
1. Seed coat or hull
2. Embryo- baby plant
3. Cotyledon- starch for
energy for the soon to be
growing plant.
yeast
barleyBREWING
CHEMISTRY
CARBOHYDRATES
glucose, maltose, maltotriosestarch
BREWING
CHEMISTRY
CARBOHYDRATES
mashing
enzyme stimulation
Other carbohydrates
pertinent to brewing:
Dextrins: sugar molecules larger than
3 simple sugars—
not digestable by yeast;
can be left in beer for sweetness
and mouthfeel
Fructose: simple sugar found in
fruits—
typically not to be used in
brewing, as gives a cidery flavor
Beta glucam gum: larger
polysaccharide found in seed hulls.
More prevalent in rye and wheat.
Can thicken and gum up the
mash– not good.
Mashing process
BREWING
CHEMISTRY
CARBOHYDRATES
What is Mashing?
Mashing is the process of turning the complex
carbohydrate—starch—of the malted barley, into simple
sugars—glucose, maltose, and maltotriose—that yeast can
eat to produce ethanol and carbon dioxide through
fermentation.
With the help of ENZYMES
Malted barley + hot water + enzymes simple sugars
BREWING
CHEMISTRY
Proteins are vital to ALL LIVING THINGS / Proteins have many functions: BREWING
CHEMISTRY
PROTEINS
Proteins have many functions; 2 of which are:
1. Physical protection– like in seed hulls
2. Enzymes– vital for all chemical reactions in living things.
BREWING
CHEMISTRY
PROTEINS
Proteins in beer are necessary for good beer foam (head)
…And healthy, happy yeasts
BREWING
CHEMISTRY
PROTEINS
Too many proteins from grain hulls can cause hazy beer BREWING
CHEMISTRY
PROTEINS
ENZYMES:
• biological catalysts (speed up chemical reactions)
• vital for chemical reactions
• functions depend on their shape
• shape (therefore, function) can be disrupted by many things :
including improper Temperature and pH
Special shape of enzyme allows for chemical reaction to occur
BREWING
CHEMISTRY
PROTEINS
Shape = Function
ENZYMES:
functions depend on their shape
shape (therefore, function) can be disrupted by many things :
including improper Temperature and pH
Disruption of protein/enzyme shape = DENATURING
this is why proper TEMPERATURE and pH are vital to good beer
BREWING
CHEMISTRY
PROTEINS
Shape = Function
ENZYMES
Mashing enzymes:
alpha-amylase
beta-amylase
BREWING
CHEMISTRY
PROTEINS
MOVEMENT OF MOLECULES
PASSIVE MOVEMENT
*Molecules move naturally ‘down’ gradients (Concentration, P, Electrochemical) WHY/HOW?
1. Simple Diffusion: movement of molecules DOWN a concentration
gradient
Ex: Adding water to distilled alcohol for proofing
Adding dye/stain to water
Adding a fruit puree to beer
BREWING
CHEMISTRY
WHAT
INFLUENCES
PASSIVE
MOVEMENT?
2. Osmosis: diffusion of water across a semi-permeable membrane
MOVEMENT OF MOLECULES
ACTIVE MOVEMENT
Reverse Osmosis:
-Moving water (by pressure) from low concentration to higher
concentration; against the gradient.
-Pushing the “dirty” water across a membrane and leaving the
pollutants/minerals behind to have “clean” water.
BREWING
CHEMISTRY
BREWING
CHEMISTRY