Gauging and proof
Every action that measures spirits takes the same gauge. You enter what you measured, and DISTRYB works out the proof and the proof gallons and shows them before you record.
The terms
These are the definitions in 27 CFR 30.11:
- Wine gallon: the liquid measure of 231 cubic inches. Gauges are entered at 60°F.
- Proof: the ethyl alcohol content of a liquid at 60°F, stated as twice the percent of alcohol by volume.
- Proof gallon: a U.S. gallon of proof spirits, or its alcoholic equivalent.
DISTRYB computes proof gallons as wine gallons × proof ÷ 100. The reports and the excise return count proof gallons.
Proof: hydrometer or true proof
Under Proof from, choose one:
- Hydrometer + thermometer (Table 1). Enter what the hydrometer reads and the thermometer's °F. DISTRYB looks up the true proof at 60°F in TTB's Table 1 (27 CFR 30.61). Readings between two whole degrees are interpolated, and the thermometer is read to the nearest degree. If Table 1 has no entry for that reading at that temperature, the gauge is refused rather than guessed.
- True proof at 60°F (already corrected). Type the true proof directly.
Proof is recorded to the nearest tenth of a degree (27 CFR 30.31(a)), from 0 to 200.
Quantity: weight, volume or meter
Under Gauged by, choose one:
- Weight (scale). Enter the net weight in pounds (gross minus tare). DISTRYB multiplies it by the Table 4 gallons-per-pound factor at that proof (27 CFR 30.64). For sweetened, flavored or colored spirits, the wine gallons come from the factor at the hydrometer's apparent proof and the proof gallons are those wine gallons × the true proof, as 30.64 directs. Table 4 runs from 1.0° to 200.0°, and a proof outside it cannot be gauged by weight.
- Volume (tank chart). Enter the wine gallons at 60°F.
- Mass-flow meter. Enter the wine gallons at 60°F.
Barrel fills and dumps are gauged by weight: each barrel's net weight (or an average at the fill) and one true proof.
Cases are gauged from the label, not a hydrometer: bottles × bottle size × label proof, with metric sizes converted at 0.264172 gallons per liter.
Rounding
Wine gallons and proof gallons are each rounded to the tenth the way 27 CFR 30.64 says: a fraction beyond the first decimal is dropped if it is less than 0.05, and counted as 0.1 if it is 0.05 or more.
When the gauge and the books disagree
When you empty a tank into barrels, enter a tank into another account, or gauge a tank before bottling, DISTRYB compares the gauge with what the books say the tank held. If they differ, it shows both figures and asks whether to record the difference as a loss or a gain. Nothing is written until you answer.
Proofing down
Water and spirits shrink when mixed, so volumes don't simply add. The Proof down estimate works from Table 4 weights instead. It is only an estimate: temperature, the water and the tank chart all move the real answer. Record the water you added, then gauge the tank.
Sweetened, flavored or colored spirits
Dissolved solids (sugar, flavoring, coloring) make a hydrometer read low, so Table 1 then gives only the apparent proof (27 CFR 30.61). The rules are in 27 CFR 30.31 and 30.32:
- 400 mg of solids per 100 mL or less: the hydrometer proof stands.
- More than 400 and up to 600 mg: the obscuration is added to the hydrometer proof. It is found by the distillation method, the pycnometer method, or the evaporation method. Evaporation is allowed only for spirits of 80° to 100° gauge proof, where 100 mg of solids per 100 mL obscures 0.4° of proof.
- More than 600 mg: a hydrometer cannot gauge it. Distil a sample in a laboratory still, restore it to its original volume and temperature, and enter the result as the true proof.
DISTRYB marks a lot as holding solids when it has had a sweetener, flavor or coloring step, or an alcohol-bearing ingredient added, or when its opening balance or its receipt in bond was ticked as sweetened, flavored or colored. The mark follows the spirits through blends and shipments. A hydrometer gauge of a marked lot is refused until you enter the dissolved solids in mg per 100 mL and, over 400 mg, how the obscuration was found. A typed true proof is taken as already corrected. Sweetened spirits received in bond go into processing, never storage (27 CFR 19.351(c)).