Mashing Chemistry & Mashing Process

Before Brewing, We need CEREALS

• How can we get access to the starches : Germination
• MALTING is the controlled germination and drying process of cereals
• to access the starches and the enzymes needed for the wort production process
• Malting process(video)

First steps in WORT PRODUCTION

• malting
• milling-grinding
• mashing
• lautering
• sparging

Milling or Grinding? 

• why do we need it? : to separate the starches from the Kernel of cereals
• the total amount of malt for a batch of beer is called the GRIST
• Kernel compromises : germ(growing part), endosperm(food), husk(protective cover)

Manual Sieve Test

• No 14 : husk remain, grist and flour go down
• No 30 : coarse grist remain then fine one go down
• No 60 : fine grist remain
• Pan : for flour remain
• A good example of milling : 14 sieve(53.4%), 30(27.6%), 60(10.6%), pan(8.4%)
• Milling and sieve test(video)

Introducing the Chemistry of Mashing

• what is mashing-in : hydrating the grist
• what is mash : a mixture of cereal and water, the liquid part is called wort
• Important parameters : Liquor to Grist ratio(3.6 L/kg), PH, Temp, Mass of extract
• What happens during mashing : 
• grist hydration
• hydrolysis of short sugars(and other dissolved components)
• gelatinization and liquidification of undissolved solids with Enzyme

Inside the grist

• Starches : great!
• B-glucan and Arabinoxylan(very long sugar) : not good
• Proteins and protein residues : ok
• Lipids : BAD

Starch vs Enzymes

• what is Starch : a mix of 25% Amylose(without branch) and 75% Amylopectin(with branch, means 1-6 link)
• the 2 most important enzymes that hydrolyze the starches : a-Amylase, B-Amylase(ase is the ending of enzymes)
• a-Amylase(optimum temp 70-75)
• faster degradation of starch than beta, lower viscosity of the wort
• cut down alpha-(1-4) link glucosidic bond of amylose and amylopectin
• create dextrin but, given time, can be reduced glucose
• B-Amylase(optimum temp 60-65)
• defines the fermentability of the wort
• degrading the amylose and cuts off maltose. 
• not attacking maltotriose and alpha-(1-6) link glucosidic bond. 
• By attacking alpha-(1-4) link Amylopectin, it creates dextrin but not degrade it(thus we have body and form)
• alpha-(1-6) link glucosidic bond : making branches, appear less frequently(1/12 probability)
• alpha-(1-4) link glucosidic bond : not making branches, most of glucose bond
• alpha-(1-4) link Amylopectin : multi sugar(polysaccharide) of plants 

Alpha and Beta Amylase-Essential enzymes in mashing
The science of step mashing

B-glucan, a true story

• makes the mash gummy, not easy to lauter
• breaking down B-glucan contributes to a clearer wort

Arabinoxylan, why not good? 

• most people call it fiber
• it significantly impart the wort and beer viscosity

Proteins

• the 2 main proteolytic enzymes : Peptidase and Protease
• Peptidase : provide the wort with amino acid nutrients(used by the yeast)
• Protease : break up the larger proteins which enhances the head retention and reduces haze

Lipid

• Off-flavors come mainly from oxidation of lipids
• best way to prevent them is low oxygen intake 

Types of mash

• Infusion mash : English style, with fully modified malt
• Step-mash : German style, with fully modified malt and Wheat or Rye
• decoction mashing : Czech style, with under modified of lower quality malt
• cereal mash : Belgian style, if using a unmalted cereal like rice

Mash out

• increase the mash temp between 75~82, in order to destroy the Amylase
• Never go above 82, or it would extract Tannins(good temp is 79)

Lautering

• targer of lautering : minimised rest wort extract in the spent grains
• the husk of malts = a natural filter layer
• Turn on the Rakes at the lowest speed possible
• Start the Vorlauf(slow recirculation)
• takes 45mins or so
• Once the wort is 3cm above the grain bed, start sparging at 82'c. 
• stop the sparge once you reach a terminal gravity of 2P or PH=6

Stepping - shoud all malt be mashed? No.

• Specialty malts : caramelized(or crystal) malts, dextrine malt and roasted malts
• "cara" malts : can be used for steeping. Lovibond 3~120 degrees
• Dextrine malts : can be used like carapils
• continental European caramelized malts : caraAroma, caramunich, caravienne, caraRed, carahell and carafoam
• Special B : very dark caramel malts(about 180 degrees L), also can be included in that family