Double Decoction Hefeweizen!

We’re brewing a traditional German Hefeweizen for Oktoberfest using the classic double decoction mash method – an old-school brewing technique that builds depth, body, and authentic flavour.  We cover the full step-by-step brewing process for a 23L batch of Weissbier, including mash schedule, decoctions, sparging, fermentation profile, and tasting notes.

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Stats

• Style: Weissbier
• ABV: 5%
• OG: 1.046 (measured 1.055)
• FG: 1.008 (measured 1.014)
• IBU: 10 (Tinseth)
• Colour: 7 EBC (SRM ~3.5)
• Carbonation: 3.5 CO₂-vol
• Batch Size: 23 L
• Boil Time: 60 min
• Brewhouse Efficiency: 67%

Ingredients

Malt & Adjuncts (5.1 kg total)

• 2.55 kg – Gladfield Wheat Malt (50%)
• 1.78 kg – Floor-Malted Bohemian Pilsner (35%)
• 0.76 kg – Gladfield Rolled Wheat (15%)
• 0.47 kg – Rice Hulls (lautering aid)

Hops

• 28 g Spalt Spalter (3% AA) — 60 min (10 IBU)

Yeast

• Lallemand (LalBrew) Munich Classic

Water Profile (adjusted)

• Mash Water: 24 L
• Sparge Water: 15.5 L
• Total Water: 39.5 L
• Acid Additions:
  • 5 ml Phosphoric Acid (Mash)
  • 0.84 ml Phosphoric Acid (Sparge)

Target Profile (ppm):

• Ca²⁺: 50
• Mg²⁺: 5
• Na⁺: 10
• Cl⁻: 60
• SO₄²⁻: 50
• HCO₃⁻: 0

(Balanced, soft water — ideal for Weissbier yeast character.)

Brewfather_Batch49_20250926

Mash Schedule (Double Decoction)

1. 45 °C – 10 min (Ferulic Acid Rest — promotes clove phenols).
2. 64 °C – 15 min (Beta Rest, part 1).
3. Pull ⅓ thick mash, 15 mins in, and boil for 15 min, then return to tun (Decoction #1).
4. 64 °C – 15 min (Beta Rest, part 2).
5. 69 °C – 30 min (Alpha Rest for body).
6. Pull ⅓ thick mash 15 mins in, and boil for 15 min, then return to tun (Decoction #2).
7. 77 °C – 10 min (Mash Out).
8. Sparge at 77 °C until pre-boil volume (~28 L) is reached.

Fermentation Schedule

• Primary: 22 °C × 7 days
• Secondary: 23 °C × 2 days
• Cold Crash: 1.5 °C × 2 days

Brew Notes

• Brewed: 10 Sept 2025
• Bottled: 21 Sept 2025
• Heat Source: 1900 W element
• Brewfather_Batch49_20250926

Step-by-Step Brewing Method

1. Water Prep
   • Adjust your brewing water to target profile (Ca 50 ppm, SO₄ 50 ppm, Cl 60 ppm).
   • Add phosphoric acid to mash and sparge water.
2. Mash In
   • Heat 24 L strike water to 45 °C.
   • Add grains and hold for 10 min (Ferulic Rest).
3. Step Mash & Decoctions
   • Raise to 64 °C, rest 15 min.
   • Pull ⅓ of the thick mash, boil 15 min, return to tun.
   • Hold at 64 °C again for 15 min.
   • Raise to 69 °C for 30 min (Alpha Rest).
   • Pull ⅓ of thick mash again, boil 15 min, return to tun.
   • Mash out at 77 °C for 10 min.
4. Sparge
   • Sparge with 15.5 L water at 77 °C until ~28 L collected.
5. Boil (60 min)
   • Add 28 g Spalt Spalter at start of boil.
   • Boil for full 60 min.
6. Chill & Transfer
   • Chill wort to 22 °C.
   • Transfer to fermenter and aerate well.
7. Fermentation
   • Pitch yeast and ferment at 22 °C for 7 days.
   • Raise to 23 °C for 2 days (clean up).
   • Cold crash at 1.5 °C for 2 days.
8. Packaging
   • Bottle or keg, targeting 3.5 vols CO₂ for lively effervescence.
   • Condition and enjoy!

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