Fortified Wines (VDN / VDL): Mutage with Alcohol, SO₂ or Cold on the AF Curve

🎯 Winemaking Goal

Monitor the density drop of a fermenting Grenache must (C10 - 26-VDN-GREN), receive an alert when reaching the fortification density threshold (1038 ≤ 1040 g/L), and use the built-in Mutage (Fortification) calculator across its 3 modes (With alcohol, With SO₂, With cold) with automatic volume/ABV recalculation, FEFO stock deduction of 96% neutral spirit, and a red fortification marker on the AF 1 curve.

✅ Prerequisites

• The Fortified wines / VDN / VDL module is enabled in Settings > Automatic actions.
• Alcool vinique 96 % (500 L, batch ALC-2026-09) is available in /stocks.
• Lot 26-VDN-GREN (100 hL, Red Grenache) is fermenting in tank C10.

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🛠️ Step-by-Step Instructions

Step 1 — Track Density Down to the Fortification Threshold (1038 g/L)

1. In Settings > Custom alert rules (/parametres?section=alertes-regles), verify your fortification density rule (Density ≤ 1040 g/L).
2. On C10 - 26-VDN-GREN, log daily AF readings (1095 → 1075 → 1055 → 1038 g/L at 23.5 °C).

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Step 2 — Run the Built-In Mutage Calculator (Alcohol, SO₂, or Cold Mode)

1. Click the purple Job button on C10 - 26-VDN-GREN and choose operation type Mutage.
2. Select one of the 3 fortification modes in the Calculator panel:
   • Mode 1 — With alcohol (VDN / Port / Rivesaltes style):
     • Must volume: 100 hL (or 110.06 hL on a secondary simulation)
     • Current ABV (% vol): 8.5 % vol · Residual sugars: 95 g/L
     • Mutage alcohol ABV: 96 % vol (stock item Alcool vinique 96 %)
     • Target ABV (% vol): 16.5 % vol (or 15.5 % vol)
     • Calculated result: Alcohol mutage: +10.06 hL alcohol → Vf 110.06 hL · final sugars 86.3 g/L · total richness 21.6 %!
   • Mode 2 — With SO₂ (sulfite mutage for sweet wines):
     • Target dose 25 g/hL with Solution sulfureuse SO₂ 18 % → 2.5 kg pure SO₂ (13.89 L solution).
   • Mode 3 — With cold (thermal arrest):
     • Target temperature 0 °C for 7 days.