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Technical Brewing Beyond Lovibond — Understanding Beer Color
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Technical Brewing Beyond Lovibond — Understanding Beer Color Bob Hansen - Technical Services Manager 4.18.08
description
Technical Brewing Beyond Lovibond — Understanding Beer Color. Bob Hansen - Technical Services Manager 4.18.08. Color and Light. What is light?. Electromagnetic wave spectrum. []. Retrieved April 13, 2008, from Encyclopædia Britannica Online: http://www.britannica.com/eb/art-70892. - PowerPoint PPT Presentation
Transcript of Technical Brewing Beyond Lovibond — Understanding Beer Color
Technical BrewingBeyond Lovibond — Understanding Beer Color
Bob Hansen - Technical Services Manager
4.18.08
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Color and LightColor and LightWhat is light?
Electromagnetic wave spectrum. []. Retrieved April 13, 2008, from Encyclopædia Britannica Online: http://www.britannica.com/eb/art-70892 Electromagnetic wave spectrum. []. Retrieved April 13, 2008, from Encyclopædia Britannica Online: http://www.britannica.com/eb/art-70892
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Color and LightColor and LightWhat is color? What causes color?
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Visible spectrum of lightVisible spectrum of light
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Reflection, Absorption and TransmittanceReflection, Absorption and Transmittance
Colored light can come to the eyes in one of three ways:
Primary Source• Directly from a light source
Secondary Sources• Light reflected off an object
• Light transmitted though an object
For Secondary Sources, Interaction of Primary Light and Secondary Source is Very Important
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Beer’s color is TransmittedBeer’s color is Transmitted
White light is transformed to yellows as blues are absorbed.
BEER
BEER
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Measuring beer colorMeasuring beer color
Many means have been used to measure and predict a beers color:
• Visually-the original and obvious way
• Using a machine
• Using a more expensive machine
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Measuring Transmitted LightMeasuring Transmitted Light
P0P0 PP
Transmittance = P/ P0
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Measuring Transmitted LightMeasuring Transmitted Light
• Transmittance measures the % age of light reaching the eye. As the photo response in our eye is proportional to the light it receives, transmittance represents most closely light or color intensity.
Beer transmittance vs wavelength
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Absorbance vs. TransmittanceAbsorbance vs. TransmittanceAbsorbance = Log 10 1/T
Absorbance = Log 10 1/(P/P0)
Absorbance = Log 10 (P0/P)
Beers Law A= eBCBeers Law A= eBC
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Absorbance vs. TransmittanceAbsorbance vs. Transmittance
Absorbance = Log 10 1/TSRM and Abs vs. Transmittance
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Wort preparation for colorWort preparation for color
- Measured using a mash with a grain bill of 50 grams/ 450 grams (11.1% )
- Similar concentration to brewers rule of thumb, 1 lb/gallon (10.7%)
- Specialty malts mashed with base malt as needed
- Corresponds to a wort of roughly 8 Plato or 1.032
- Beer / Wort normally diluted to get absorbance below 2.0
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Transmission Spectrum of Specialty maltsTransmission Spectrum of Specialty maltsTransmission at 20 SRM
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Caramel 60
Caramel 120
Extra Special
2-Row Dark
Roasted Barley
Black Malt
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Caramel Malt Transmittance
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Black Malt Transmittance
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A whiter shade of pale? 2 SRMA whiter shade of pale? 2 SRM
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A whiter shade of pale?A whiter shade of pale?
Tranmittance spectrum at 2 SRM
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Caramel (90%)
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Tranmittance spectrum at 2 SRM
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Caramel (90%)
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Orange or Tan 10 SRMOrange or Tan 10 SRM
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Orange or TanOrange or Tan
Transmittance at 10 SRM
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Caramel (68%)
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Transmittance at 10 SRM
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Caramel (68%)
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Red or Brown-20 SRMRed or Brown-20 SRM
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Red or Brown- 20 SRMRed or Brown- 20 SRM
Transmittance spectrum at 20 SRM
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Caramel (53%)
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Mahogany or Black-30 SRMMahogany or Black-30 SRM
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Mahogany or Black-30 SRMMahogany or Black-30 SRM
Transmittance spectrum at 30 SRM
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Caramel (44%)
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Spectrum of Same Color WortsSpectrum of Same Color Worts
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Caramel Malt Black Malt
10 SRM Orange Tan
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30 SRM Mahogany Black
Summary-Specialty Malt ColorSummary-Specialty Malt Color
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Summary-formulating for colorSummary-formulating for color• A beers color is caused by the selective transmission of light
• Light source, path length and concentration are important to measuring and viewing a beers color
• Absorption of light by different classes of malt is mostly equivalent across the spectrum of visible light
• Current SRM is good for measuring batch to batch variability within the same recipe
• Current SRM color rating is ineffective for describing the actual color of darker colored beers.
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Summary-formulating for colorSummary-formulating for color
• Full spectrum analysis can give a truer picture of beer color.
• At equivalent SRM the color from different malts within the same class will be the same, though flavor may vary.
• True perceived beer color could be predicted from recipe.
• Dark roasted malts absorb more strongly across the spectrum, leading to darker beers and browner tones at equivalent SRM.
• Tools could be developed to be both predictive and descriptive of true beer color.
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Questions?Questions?
Thank You!
