[...]... via e-mail – rick.blankemeier@stonebrewing.com Thanks! • Thanks to Mitch Steele, Steve Gonzales, Sean Taylor, and all of Team Stone • A special thanks to the Brewers Association for hosting another awesome CBC Thanks! • And a special thanks for being an awesome crowd! References • • • • • • • • • • • • • • • • • • • • Briggs, D., Boulton, C., Brookes, P., Stevens, R., 2004 Brewing: Science and Practice... • Good to establish color thresholds for your core brands • Diagnose specialty grain or grainout issues Color • Colorimetric at 430nm • Measures absorbency in the blue part of the visible spectrum of light • Waste/Hazard Issues – None, able to dispose of reagents down the drain w/o treatment • Cost – Little to none (besides cost of spectrophotometer) • Cost Benefit – Establish color specs for your core... color specs for your core beers – Gives you the ability to adjust the color to your needs Bitterness • Measures the approximate* amount of isoalpha acids in a sample • Uses liquid-liquid extraction to separate the iso-alpha acids* from acidified wort/beer into 2,2,4-trimethylpentane (iso-octane) • Great for establishing an empirical specification for your core beers • Also great for determining hop utilization... Substances • Measures the concentration of oxidative precursors in wort due to lipid peroxidation • Overheating your brew leads to free radical formation • Free radical formation leads to oxidation • Oxidation in beer leads to suffering (and poor shelf-life) TBARS Assay • Colorimetric at 517 nm • Measures against a MDA standard to generate a standard curve Standard Curve 0.6 y = 0.0052x + 0.0138 R² =... proteins • Basically, it measures the bioavailability of nitrogen to yeast • Adjunct brewers have to worry about low FAN levels • Too much FAN = potential micro issues and fusel oil formation in high gravity beers • Don’t worry about adding nutrients like urea! • High FAN can also lead to haze issues and some amino acids can also lead to higher diacetyl formation rates in fermenting beer Free Amino... Diagnose haze issues in beer – Utilize enzymes to help with poor lauters or haze issues Polyphenols/Tannins • Comes primarily from darker malts, hops, barrels/wood aging • Imparts strong flavors – too much and it causes astringency • Complexes with proteins at low temperatures to form chill haze Polyphenols • Ferric iron binds to polyphenols • Good way to monitor post-dryhop tannin levels • Absorbance... at 600nm • Waste/Hazard Issues – None, able to dispose of reagents down the drain w/o treatment – Ammonia is concentrated and stinky • Cost – ~$100 for 20 tests • Cost Benefit – Potential for determining when a barrel has given up all of its flavor – Potential to diagnose haze issues in beer Summary • Establish empirical standards for your beer • Scale up your brewery keeping those standards in mind... Spectrophotometer Color – Spectrophotometer ABV – Anton Paar Alcolyzer or Ebulliometer Analytical Testing • Level 1 – Color Analysis (ASBC Method Beer 10A) – Bitterness (ASBC Method Beer 23) • Level 2 – Beta-Glucans (Custom Method) – Polyphenols (ASBC Method Beer 35) • Level 3 – FAN (ASBC Method Beer 31) – TBARS (Method on the kit) Color Analysis • One of the simplest assays using a spectrophotometer... of Iso-Alpha-Acids During Wort Boiling Journal of the Institute of Brewing 116 (2010) 332-338 Khatib, A., 2006, Studies of iso-alpha-acids: analysis, purification, and stability Doctoral Dissertation, Leiden University Kishimoto, T., 2008 Hop-Derived Odorants Contributing to the Aroma Characteristics of Beer Doctoral Dissertation, Kyoto University Malowicki, M., Hop Bitter Acid Isomerization and Degradation... The Role of hops in Brewing Journal of the Institute of Brewing 117 (2011) 259-267 Techakriengkrai, I., Paterson, A., Taidi, B., Piggott, J., Relationships of Sensory Bitterness in Lager Beers to Iso-Alpha-Acid Contents Journal of the Institute of Brewing 110 (2004) 51-56 Research Newsletter of the International Centre for Brewing and Distilling, Winter 2003 AMERICAN SOCIETY OF BREWING CHEMISTS, Report . x0 y0 w0 h0" alt="" Using Spectrophotometry to Improve your Brewing Process Rick Blankemeier Quality Assurance Analyst Stone Brewing Co. Goals •. that affect your process? – How much would it save you to keep your beer on the shelf for an extra month? – Able to increase the batch size of your brew