Practical Malting and It’s Influence on Malt Analysis Guest Speaker : Tyler Schoales

About Me Tyler Schoales BSc Applied Molecular Sciences, MAGB Malting Diploma 11 years global malting experience Avid homebrewer (Grainfather, SS BrewTech), 20 Gallon SS BrewTech Infusion Mashtun and Brewmaster Kettle Currently National Sales Manager for GWM

Why Barley ? Practical Malting Steeping Germination Kilning Outline Why Barley ? Practical Malting Steeping Germination Kilning

Why Malting Barley? Barley contributes the sensory characteristics associated with beer: Source of extract, hence alcohol Mash Enzymes – Alpha, Beta Amylase to name a few Source of Yeast nutrients and in particular FAN Excellent buffer of pH in Wort Milled husk materials act as a filter bed during mash filtration (Lautertun & mash tun) A source of foam stabilizing proteins Source of polyphenols => antioxidant power Sensory characteristics – flavor, color, aroma, body, etc. Talk to wheat as important for some beers flavor and functionality Historical use (or attempted use) of other grains for beer show the enduring value of barley.

Barley Morphology Cross Section

Practical Malting Overview of Malting Process

Practical Malting Steeping 36-48 hours Primary objective: To hydrate the grain Embryo is “activated” Water and Oxygen Uptake Disappearance of simple sugar Generation of heat, and carbon dioxide Production of Hydrolytic Enzymes Each kernel is alive Each kernel must breathe, cast off waste material and begin to grow a new barley plant Factors that influence this are water temperature, protein content Other factors include : type of steeping plant, variety, germ energy, and germ capacity tests, ambient air

Practical Malting Biochemistry of Steeping At approximately 27% moisture content of the kernel the following biochemical changes begin to occur: Initiated respiration of malt kernel Uptake of oxygen and release of Co2 and heat Synthesis of Gibberellic acid in the embryo …. and scutellum?

Practical Malting Maltster Rounds - Steeping

Practical Malting Germination – 4 to 5 days Primary objective: Synthesize enzymes that will “unlock” the starch contained in the endosperm for brewers to utilize Embryo is actively synthesizing and subsequently transporting GA3 through the scutellum and alluerone layer which stimulates the following Enzyme synthesis Contents of the endosperm are partially degraded Factors that influence this are time and temperature of vessel Other factors include : type of germination vessel, airflow, variety, barley quality, humidity, ambient conditions, moisture, turns, bed depth

Practical Malting Saladin Germination Vessel

Practical Malting Biochemistry of germination Germination Sequence Contents of the starchy endosperm are partly degraded and depleted Cell wall materials (hemicelluloses, and B-Glucans) Protein matrix Starch Granules (large and small) The embryo metabolizes and grows, using chemical feedstocks supplied by the endosperm breakdown. The grain is alive: respires, experiences stress….

Practical Malting Biochemistry of germination

Practical Malting Kilning – 16 to 24 hours Primary objective of kilning: Prevent further growth and modification of the malt kernel Achieve stability of malt for storage and transport Stabilize and preserve enzyme package Develop color, flavor and aroma Physical changes during kilning: Malt shrinks about 25-35% Malt becomes more friable as malt is kilned Microflora greatly reduced on kilned malt

Practical Malting Kilning – Stages Stages of the kilning process include: Free drying (Pre break) – Typically 44%  14% moisture content Force drying (Post break) – Typically 14%  5% moisture content Curing – 5% and lower

Latent heat of evaporation Practical Malting Kilning – Stages Stages of the kilning process include: Free drying (Pre break) – Typically 44%  14% moisture content Allotted time 12-14 hours Average starting temperature 140 F Wicking easily accessible moisture off of malt Surface moisture rapidly removed Latent heat of evaporation Evaporation Air Flow Relative humidity = 100%

Relative humidity < 100% Practical Malting Kilning – Stages Stages of the kilning process include: Force drying (Post break) – Typically 14%  5% moisture content Allotted time 5-7 hours Temperature ramping from 140 F to 166 F Forcing migration of moisture from internal to external portion of the malt Surface moisture removed Heat Evaporation Air Flow Relative humidity < 100% Diffusion

Practical Malting Kilning – Stages Rate of moisture removal = Stages of the kilning process include: Curing – 5% and lower Allotted time 1-3 hours Typically temperature reaching up to 194 F Evaporation Diffusion Rate of moisture removal = Rate of moisture uptake Air Flow Relative humidity constant Heat

Practical Malting Biochemistry of kilning Enzymes are very unstable at higher moistures and denature very easily. By slowly increasing temperatures (115 F to 150 F) as moisture decreases to below 30%, we are able to stabilize enzymes. thereby preventing denaturing from occurring.

Practical Malting Biochemistry of kilning (>176°F) (149-158°F)

Practical Malting Biochemistry of kilning The Maillard Reaction is responsible for the color and flavor of the malt produced Moisture Sugar Heat Protein Flavors such as malty, bready, biscuit, nutty, cracker as well as aromas contributed by pyrazine through the Maillard reaction in kilning

Practical Malting Maltster Rounds - Kilning

Questions

References Bamforth, C.W. (2003). ‘Barley and malt starch in brewing: a general review’. MBAA TQ, 40(2): 89-97 Briggs D.E. (1998). Malts & Malting. Blackie Academic Press. Cook, David. ‘Malt from the brewer’s perspective’ (2014) Briggs, D.E., Boulton, C.A., Brookes, P.A. & Stevens, R. (2004). ‘Brewing: Science and practice’, Woodhead Publishing Ltd., Cambridge, UK.