Updated May 2026.
Ethanol evaporates. A sealed bottle of vodka does not “go bad” like dairy. Typical US unflavored vodka is 40% ABV / 80 proof (27 CFR 5.142 floor). This page will not invent a weeks-to-empty rate or a “30 minutes in the sun” clock. USDA/FSIS leftover rules are for perishable food, not a capped spirit.
Shelf-life language that belongs on the sister FAQ is at how long does vodka last. Flavor can fade after air sits in the neck. That is quality, not a USDA pathogen clock.
What actually evaporates
Vodka is ethanol plus water (and, on flavored SKUs, sugar and aroma). Ethanol is more volatile than water. NIOSH lists ethyl alcohol’s boiling point at 173°F. Leave a wide glass of 80-proof vodka uncovered in a warm room and some of the ethanol will leave as vapor. That is physical chemistry. It is not a stopwatch.
The 2022 URL said an opened bottle in the sun was gone in “30 minutes at least,” that 61°F was a magic ceiling, and that an opened bottle at room temperature “may last for weeks or even months or years.” Those are invented timelines. We will not replace them with a different invented number. How fast a given glass loses ethanol depends on surface area, temperature, airflow, and how full the bottle is. A jigger left on a porch is not a sealed 750 mL.
| Situation | What is true | What is not a clock |
|---|---|---|
| Sealed, unflavored 40% vodka | Does not spoil like milk; ethanol + water, high ABV | A USDA leftover day-count |
| Opened, recapped, cool and dark | Quality can drift as air sits in the neck | Official open-bottle months (unused — see sister FAQ) |
| Wide glass, warm, uncovered | Ethanol evaporates; aroma goes first | “Empty in 30 minutes” |
| Flavored vodka | Sugar and citrus oils are a different bottle | Treating it like unflavored 80 proof |
| USDA/FSIS 2-hour rule | Perishable cooked leftovers at room temp | A sealed spirit statute |
USDA leftovers are not a vodka statute
FSIS says perishable leftovers must be refrigerated within two hours (one hour if the air is above 90°F), and that fridge leftovers are a 3–4 day quality-and-safety window for cooked food. That chart is chicken, casseroles, and deli meat. It is not a fifth of vodka. Packaged 80-proof spirits are a poor home for the bacteria leftover charts worry about. A swollen, leaking, or clearly contaminated bottle is a discard. A six-year-old sealed vodka that tastes a little flat is a disappointment, not a USDA leftover case.
Official open-bottle month counts were unused on the sister page this project there, not a new number here. Keep the cap on. Store it cool and dark. Stand the bottle up. That is enough.
Cooking is not “the vodka vanished”
The old URL reprinted a cooking-retention pair (15 minutes leaves 40% of the alcohol, another 15 leaves 35%). Those figures live on a USDA nutrient-retention table for cooked dishes, not as a sealed-bottle evaporation rate. We did not re-fetch that table this run, so we will not reprint the percentages. Conservative line: some ethanol cooks off; a vodka sauce is not alcohol-free just because it simmered. Do not use the stove as a proof test, and do not use the leftover chart as a bottle clock.
What a 1.5 oz pour still is
A 1.5 oz shot of 40% vodka is one NIAAA standard drink whether the bottle has been open a week or a year. Evaporation in a recapped bottle is not a free reduction in standard drinks. If the level dropped because someone poured it, count the poursvodka drink math.
Freezer vodka is a texture choice, not a preservation statute. Cold slows vapor loss; it does not turn an open bottle into a sealed one. A half-empty fifth with a loose pour spout is more air than a full, capped 750 mL. Recap it. Do not leave a rocks glass of vodka on a sunny sill as a science project — and do not treat that glass as a bottle-life study.
Sources
- NIOSH Pocket Guide, Ethyl alcohol: boiling point 173°F (ethanol is volatile). Fetched this project.
- 27 CFR 5.142: US vodka bottled ≥40% ABV. Typical unflavored supermarket vodka is 80 proof.
- USDA FSIS, Leftovers and Food Safety: 2-hour / 1-hour-above-90°F rule and 3–4 day fridge leftovers — perishable cooked food, not a sealed spirit.
- Sister FAQ how long does vodka last: sealed vodka does not spoil like beer; official open-bottle months unused.
- Old “30 minutes in the sun” / 61°F / weeks-to-empty clocks — unused.