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Proofing calculator: true proof, gallons and the cut.
Correct a hydrometer reading to true proof at 60°F with TTB Table 1, turn a net weight into wine and proof gallons with Table 4, and see how much water brings a run down to bottling proof. It's the same gauging math StillReporting runs every day on a working DSP floor.
Cut to 80 proof
- Fill the vessel to
- Final proof
- Proof gallons
- conserved
- Bottle yield, 750 mL
Ethanol and water contract slightly when mixed, so add water to the fill line, then check with your hydrometer.
A calculator, not an official gauge: gauge and keep records under 27 CFR Part 30 with your own instruments. True proof uses TTB Gauging Manual Table 1 (27 CFR 30.61) with TTB's published interpolation, digitized by Max Oppedahl and Greg Miller (UC Davis) with three 1978 printing errors corrected. Gallons from weight use Table 4 (27 CFR 30.64). The cut keeps proof gallons constant. Readings outside the published tables are refused, never guessed.
Built into StillReporting
Gauge it once. It's on the record.
In StillReporting, the gauges you record become your Part 19 records and flow into the monthly TTB reports. We're inviting a small founding cohort before public launch.