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          MASTER FERMENTATION CALCULATOR SPECIFICATION - PART 1: BREWING
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A technical backend manual covering sugar, density, color, bitterness,
enzymatic power, carbonation, and historical cask capacities mapped directly
to standard SI metric base, derived, and accepted non-SI units.
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1. EXTRACT, SUGAR CONCENTRATION & DENSITY (GRAVITY)
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*   Specific Gravity (SG)
    - Description: Dimensionless ratio of the weight of a volume of wort/beer to
      the weight of an equal volume of pure water at a standard temperature.
    - Core Users: Universally preferred by Homebrewers and small UK/US Craft
      Microbreweries using hydrometers.
    - Metric / SI Baseline Value: Dimensionless ratio. At standard reference
      density (1.000), mass density equals exactly 1,000 kg/m³ (SI Base: kg, m).

*   Degrees Plato (°P)
    - Description: Measures the concentration of dissolved solids as a mass
      percentage of sucrose (grams of sucrose per 100 grams of liquid).
    - Core Users: Absolute global standard for Large Commercial breweries and
      highly professional Craft/Micro operations.
    - Metric / SI Baseline Value: Mass fraction unit (1°P = 0.01 kg of sucrose / kg of solution).

*   Degrees Brix (°Brix)
    - Description: Functionally identical to Plato, measuring percentage sucrose
      by weight, derived originally from different calibration tables.
    - Core Users: Widely used by Homebrewers and small Craft/Micro brewers when
      taking raw measurements using optical or digital refractometers.
    - Metric / SI Baseline Value: Mass fraction unit (1°Brix = 0.01 kg of sucrose / kg of solution).

*   Degrees Balling (°Balling)
    - Description: The earliest mass-percentage scale for dissolved sugars, older
      than Plato and slightly less mathematically precise at high temperatures.
    - Core Users: Historical legacy. Found in traditional European breweries.
    - Metric / SI Baseline Value: Mass fraction unit (1°Balling = 0.01 kg of sugar / kg of solution).

*   Gravity Points / Gravity Units (GU)
    - Description: A simplified integer shorthand representing the fractional part
      of Specific Gravity.
    - Core Users: Homebrewers and small Craft/Micro recipe developers for raw math.
    - Metric / SI Baseline Value: Dimensionless integer scale where:
      GU = (Mass Density in kg/m³ - 1000).

*   HIGH-PRECISION CONVERSION FORMULAS:
    - SG to GU:
        GU = (SG - 1.000) * 1000
    - GU to SG:
        SG = 1.000 + (GU / 1000)
    - SG to Plato (Highly Precise ASBC Polynomial Formula):
        °P = -616.868 + (1111.14 * SG) - (630.272 * SG^2) + (135.997 * SG^3)
    - Plato to SG (Precise De Clerck Formula):
        SG = 1 + (°P / (260.5 - [°P * 0.3896]))
    - Brix to Plato (Wort Correction Factor Integration):
        °P = Brix / WCF
        (Note: Default WCF for beer is 1.04. Unfermented wort contains proteins
        and beta-glucans that skew the light refraction index compared to wine)

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2. CROSS-DISCIPLINARY HYDROMETER TEMPERATURE CORRECTION
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Most winemaking and brewing hydrometers are calibrated to 60°F (15.5°C) or 68°F
(20°C). If the fluid is hot from the brewhouse or cold from the wine cellar, you
must apply a correction factor to the Specific Gravity before running final calculations:

*   Formula (Where T is temperature in Fahrenheit):
    SG_corrected = SG_measured + ((0.000004811 * T^2) - (0.005408 * T) + 0.1292)
    - SI Base Unit Application: Standardizes measurements dynamically to prevent
      density skewing caused by thermal molecular expansion.

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3. COLOR QUANTIFICATION
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*   Standard Reference Method (SRM)
    - Description: Color density calculated via spectrophotometer by measuring the
      attenuation of light at 430 nanometers through a 0.5-inch path cell.
    - Core Users: Broadly used across all US brewing tiers.
    - Metric / SI Baseline Value: Absorbance metric. Light wavelength is 430 x 10⁻⁹ m
      (SI Base: m). Path length cell is exactly 0.0127 m.

*   Degrees Lovibond (°L)
    - Description: Legacy system based on a qualitative visual comparison of beer or
      wort samples against a series of tinted amber/yellow glass slides.
    - Core Users: Homebrewers, Craft/Micro recipe developers, and maltsters.
    - Metric / SI Baseline Value: Qualitative visual matching scale index.

*   European Brewery Convention (EBC)
    - Description: Color density calculated at 430 nanometers, utilizing a
      metric 10-millimeter (1 cm) path cell instead of an inch cell.
    - Core Users: Large Commercial breweries globally, and European Craft/Micro tiers.
    - Metric / SI Baseline Value: Absorbance metric. Light wavelength is 430 x 10⁻⁹ m.
      Path length cell is exactly 0.01 m (10 mm).

*   CONVERSION FORMULAS:
    - Lovibond to SRM:
        SRM = (1.35 * °L) - 0.6
    - SRM to EBC:
        EBC = SRM * 1.97
    - EBC to SRM:
        SRM = EBC * 0.508

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4. HOP BITTERNESS CHEMISTRY
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*   International Bitterness Units (IBU) / European Bitterness Units (EBU)
    - Description: Chemical measurement of isomerized alpha acids in liquid beer,
      where 1 IBU equals exactly 1 milligram of isomerized alpha acid per liter.
    - Core Users: Universal across all global brewing tiers.
    - Metric / SI Baseline Value: Mass concentration per volume unit.
      1 IBU = 0.001 g/L = 0.001 kg/m³ (SI Base: kg, m).
    - Conversion Formula: IBU to EBU is treated functionally as 1:1.

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5. ENZYMATIC ACTIVITY (DIASTATIC POWER)
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*   Degrees Lintner (°L or °Lintner)
    - Description: Measures the capability of malted grains to break down complex
      starches into simpler fermentable sugars under defined laboratory conditions.
    - Core Users: US Homebrewers, US Craft/Micro brewers, and North American Maltsters.
    - Metric / SI Baseline Value: Enzyme catalytic conversion index.

*   Windisch-Kolbach Units (WK)
    - Description: European standard measurement for the enzymatic power of malted grains.
    - Core Users: European Maltsters, Large Commercial breweries, and international craft fields.
    - Metric / SI Baseline Value: Catalytic conversion index related to SI derived unit Katal (mol/s).

*   CONVERSION FORMULAS:
    - Lintner to WK:
        WK = (Lintner * 3.5) - 16
    - WK to Lintner:
        Lintner = (WK + 16) / 3.5

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6. CARBONATION LEVELS
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*   Volumes of CO2 (v/v)
    - Description: The ratio of the volume of dissolved carbon dioxide gas to the
      total volume of the liquid beer container hosting it at standard temperature/pressure.
    - Core Users: US/UK Homebrewers and US/UK Craft/Micro breweries.
    - Metric / SI Baseline Value: Dimensionless volumetric ratio (1 Volume = 1 m³ gas / m³ liquid).

*   Grams per Liter (g/L)
    - Description: The physical mass of carbon dioxide gas dissolved per liter of liquid.
    - Core Users: Large Commercial breweries worldwide, and Metric European Craft/Micro sites.
    - Metric / SI Baseline Value: Mass concentration per volume (1 g/L = 1 kg/m³).

*   CONVERSION FORMULAS:
    - Volumes of CO2 to g/L:
        g/L = Volumes * 1.96
    - Grams per Liter to Volumes:
        Volumes = g/L * 0.51

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7. MODERN BREWERY PRODUCTION VOLUME
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*   US Beer Barrel (bbl)
    - Size / Description: Standard equipment capacity and production unit in North America.
    - Metric / SI Baseline Value: Volume unit. Exactly 31 US gallons / 117.34776 Liters (0.11735 m³).

*   Hectoliter (hL)
    - Size / Description: Standard unit equal to exactly 100 liters of fluid volume.
    - Metric / SI Baseline Value: Accepted Non-SI Metric Volume unit. Exactly 100 Liters (0.1 m³).

*   CONVERSION FORMULAS:
    - US Barrel (bbl) to Hectoliters (hL): 1 bbl = 1.17347 hL
    - Hectoliter (hL) to US Barrels (bbl): 1 hL = 0.85218 bbl
    - US Barrel (bbl) to US Gallons: 1 bbl = 31 US Gallons
    - US Barrel (bbl) to Liters: 1 bbl = 117.347 Liters

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8. HISTORICAL CASK VOLUMES (BREWING STANDARD)
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In 1824, the UK standardized these around Imperial Gallons. The historical sequence
builds proportionally off the foundational "Firkin".

*   Pin
    - Volumetric Size: 4.5 Imperial Gallons / 5.4 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 20.4574 Liters (0.02046 m³).

*   Firkin
    - Volumetric Size: 9 Imperial Gallons / 10.81 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 40.9148 Liters (0.04091 m³).

*   Kilderkin
    - Volumetric Size: 18 Imperial Gallons / 21.62 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 81.8296 Liters (0.08183 m³).

*   Barrel (UK Historical / Real Ale Barrel)
    - Volumetric Size: 36 Imperial Gallons / 43.23 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 163.6592 Liters (0.16366 m³).

*   Hogshead
    - Volumetric Size: 54 Imperial Gallons / 64.85 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 245.4888 Liters (0.24549 m³).

*   Puncheon
    - Volumetric Size: 72 Imperial Gallons / 86.47 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 327.3184 Liters (0.32732 m³).

*   Butt
    - Volumetric Size: 108 Imperial Gallons / 129.70 US Gallons.
    - Metric / SI Baseline Value: Volume unit. Exactly 490.9776 Liters (0.49098 m³).

*   CONVERSION MATRIX FOR CASK VOLUMES:
    - 1 Pin = 0.5 Firkins
    - 1 Firkin = 2 Pins = 0.5 Kilderkins = 0.25 UK Barrels
    - 1 Kilderkin = 2 Firkins = 4 Pins = 0.5 UK Barrels
    - 1 UK Barrel = 2 Kilderkins = 4 Firkins = 8 Pins
    - 1 Hogshead = 1.5 UK Barrels = 6 Firkins = 12 Pins
    - 1 Puncheon = 2 UK Barrels = 8 Firkins = 16 Pins
    - 1 Butt = 3 UK Barrels = 12 Firkins = 24 Pins
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