Management of Malting for Flavor Development and its Impact on Malt Analyses Barley Improvement Conference January 12, 2015 Paul Kramer – Rahr Malting Co. • Introduction to Malting • Malt Flavor Development during Kilning • Malt Analyses Interactions • Rahr Wort Flavor Observations • Malting Process Barley Unloading Clean & Grade Transfer to Silo Kilning Germination Steeping Transfer to Silo Malt Cleaning Loading Malt Malting Process - Flavor CCP Barley Unloading Clean & Grade Transfer to Silo Kilning Germination Steeping Transfer to Silo Malt Cleaning Loading Malt Barley Conversion to Malt Products from Malting Process Malt 82% Respiration 2% Water Vapor 8% Malt Sprouts 4% Barley Byproducts 4% Barley Cleaning and Grading • Segregate barley by variety and crop year • Aspiration • Scalping • Metal removal • Gravity Steeping • Steeping is the most critical stage of the malting process • Objectives of steeping – Clean and rinse barley surface – Remove growth inhibitors – Uniformly hydrate the barley kernels – Provide O2 and remove CO2 – Control temperature to ensure uniform respiration – Hydrate barley to targeted moisture • Steeping Control Parameters – Time – Water volume immersions/sprays – Water temperature – O2 injection during immersion – CO2 removal during drain periods Germination Control Parameters • Germination Time – Variety & customer dependant – Typically 3.0 -5 days • Germination Bed Temperature – Air on or house temperature • Typically 54-600F – 100% humidity – Air off or exhaust temperature • Typically 68-720F • Airflow – 6-11 cfm/bushel. • Water additions – Volume and timing • Machine Runs – Frequency and timing relative to variety Objectives of Kilning • Arrest biochemical reactions and stabilize enzymatic activity • Develop color, aroma, and flavor • Make the malt crisp and friable for milling • Reduce moisture for storage stability – Typically go to kiln at 46-48% moisture and reduce it to 4-5% Types of Malt Products Malt Color (°L) Uses 2 Row Pale 1.5 to 2.5 Most beers 6 Row Pale 1.5 to 2.5 Most beers Vienna 4 to 6 Darker beer, Martzen Pale Ale 2 to 4 Ale, Brown Ale Munich 5 to 10 Dark lagers and ales Caramel Pils 5 to 15 Dark lagers and ales Caramel 8 to 120 Dark lagers and ales Aromatic 17 to 21 Dark lagers and ales Crystal 40 to 150 Paler ales Amber 15 to 40 Barley wine, sweet Stout Brown 40 to 60 Brown Ale, Stout, Porter Special B 90 to 140 Many beers Chocolate 300 to 500 Stout, Porter Black 400 to 600 Stout, Porter Roasted barley 300 to 800 Irish Stout 95%+= of malt use is the lower colored “kilned malt” Phases of Pale Malt Kilning • Germination Phase - Free drying (130-150F) – Germination continues and is even expedited – High enzymatic activity – Moisture is lost rapidly • Enzymatic Phase – Forced Drying /Breaking phase (150-160f) – Embryo slows & dies – Enzymatic activity declines – Hydrolytic products accumulate – Break point – air off the bed drops below 100% humidity and the exhaust temperatures begin to increase • Chemical Phase – Curing (180-195f) – Flavor Development – Maillard browning reaction (amino acids and reducing sugars) – Oxidized polyphenols – No more free drying, higher heats are used to force the remaining moisture out of the kernel (kilned malts) (specialty malts - roasters) Malt Changes during kilning Phase 1 Phase 2 Phase 3 50 Diastatic Power 40 Alpha-amylase 30 Moisture 20 % Moisture Color 10 0 0 8 16 24 32 40 48 Time (hr) Traditional Kilning Schedule 200 70 60 180 Airflow 50 160 40 140 30 20 CFM/Bu. Temperature 120 10 100 0 2 4 7 10 12 15 Hours Temperature Air Flow Daily Kiln Firing Temperature Profile Traditional vs. Flavor 200 190 180 170 160 150 140 Temperature 130 120 110 100 1 2 3 4 5 6 7 8 9 101112131415161718 Hours Flavor Traditional Malt and Wort Flavor Analyses Malt Analyses • Malting - Biological process – Raw material variation (variety and viability) – Processing variation – Analyses variation • Predictable analytical interactions in a malt analyses – Color with modification factors – Modification with solubilized proteins – Extract with solubilized protein, total protein and sizing 13 Crop Metcalfe Production Correlation Matrix N=117 Malt Analyses • Malting - Biological process – Raw material variation (variety and viability) – Processing variation – Analyses variation • Predictable analytical interactions in a malt analyses – Color with modification factors – Modification with solubilized proteins – Extract with solubilized protein, total protein and sizing • Congress wort flavor – Rahr taste panel results Congress Wort Flavor Analyses Rahr Malting Taste Panel Averages Congress Wort Flavor Analyses Rahr Malting Taste Panel Averages Congress Wort Flavor Analyses Rahr Malting Taste Panel Averages 13 Crop Metcalfe Production Correlation Matrix N=117 Multiple Regression 14 Metcalfe Congress Wort and Malt Analyses • Analytical factors correlating with Congress Wort flavor • Higher total protein = poorer wort flavor • Lower modification = better wort flavor Malt Analyses • Malting - Biological process – Raw material variation (variety and viability) – Processing variation – Analyses variation • Predictable analytical interactions in a malt analyses – Color with modification factors – Modification with solubilized proteins – Extract with solubilized protein, total protein and sizing • Congress wort flavor • Not an absolute predictor of brewhouse performance • Not an indicator of beer flavor Beer Flavor • Beer Flavor • Specialty malt and beer flavor - well understood • Hops and beer flavor – well understood • Pale malt processing’s impact on beer flavor? • Barley varieties and beer flavor? • Develop a standardized • Malting protocol • Brewing protocol • Beer flavor testing protocol to access these variables .