Unopened, no. A sealed bottle of cognac, armagnac or calvados at around 40% ABV doesn't spoil, and there's no realistic risk of it going "off" the way food or wine can. Once you've opened it, the spirit doesn't go bad either, but it does slowly change: flavour and aroma fade a little as air gets in, over a timeline measured in years rather than months for most drinkers. It's a quality question, not a safety one.
Here's what's actually happening, and how to store a bottle so it stays at its best for as long as possible.
Why unopened brandy doesn't spoil
Wine and beer can genuinely go off in the bottle because they're low-alcohol and still biologically active. Cognac, armagnac and calvados are distilled spirits at roughly 40% ABV, which is well past the point where alcohol is hostile to the microorganisms that cause spoilage. Sources vary on the exact inhibition threshold (estimates range from around 10–12% up to 20%+ depending on the source), but every figure found sits well below the ~40% strength these brandies are bottled at (Galactic; cyalcohol.com). In plain terms: there's no realistic bacterial contamination risk in a bottle this strong.
The official cognac industry body puts it simply: a properly re-corked bottle "keeps for several years after opening without losing its aromas, unlike wine" (cognac.fr/BNIC). Armagnac's industry body goes further for unopened bottles. Closed and undisturbed, they say a bottle "keeps almost indefinitely, provided the cork is checked or replaced every 5 to 10 years" (armagnac.fr/BNIA).
One thing worth being clear on: none of these spirits continue to mature once bottled. Barrel ageing is where cognac and armagnac actually develop (the slow exchange of air through oak, plus tannin extraction from the wood), and none of that happens in sealed glass (armagnac.fr). A 12-year-old bottle that's sat in a cupboard for another decade is still, chemically, a 12-year-old spirit. This is well corroborated across official sources and is one of the more settled facts in this piece.
What actually changes once you open a bottle
Once air gets into the bottle, two things happen slowly: evaporation and oxidation. As you pour out some of the spirit, the empty space above the liquid (headspace) grows, and more of the volatile aroma compounds (the lighter alcohols and esters that carry a lot of a brandy's character) gradually escape into that air rather than staying dissolved in the liquid. Genuine chemical oxidation also occurs, though a detailed whisky-focused technical analysis notes that what's often loosely called "oxidation" in spirits is mostly this evaporative loss rather than true oxidation reactions, which are actually more limited (Whisky and Wisdom). The practical effect either way is the same: a bottle that's been open a long time, especially one that's more than half empty, will taste a little flatter and less aromatic than a fresh one.
How long does this take to become noticeable? Honestly, there's no single agreed number, and a lot of the "X months" figures repeated online don't trace back to anything solid. What we found:
- Armagnac's own industry body gives a specific, official figure: once opened, they recommend drinking within 1–2 years, noting that even mild oxidation from air entering the bottle can change the taste (armagnac.fr/BNIA).
- A spirits educator at Skurnik Wines gave a similar range for spirits generally: flavour changes become noticeable over one to two years open (VinePair).
- Writer W. Blake Gray, citing whisky writer François Monti, found opened bottles held up for about 18 months in a warm climate and closer to 2.5 years in a cooler one, a useful reminder that your storage conditions matter as much as the calendar (The Gray Report).
- At the more relaxed end, Wine Spectator quotes cigar and spirits writer Jack Bettridge saying a sealed, opened bottle will keep essentially indefinitely, with only a slight loss of strength over time (Wine Spectator).
Given that spread, the honest summary is: expect the most noticeable freshness in the first one to two years after opening, with a bottle remaining perfectly good to drink well beyond that, just gradually less vivid. Treat "1–2 years" as a guide for when to prioritise finishing a bottle, not an expiry date.
How to actually store a bottle
The advice here is consistent across cognac, armagnac and (by extension, since the same ~40% ABV logic applies) calvados, even though calvados-specific numeric guidance is thinner in the record than the other two:
- Store it standing up, not on its side. This is the opposite of wine, and for a specific reason: at 40% ABV, the spirit will slowly degrade the cork if it's in constant contact with it. Both BNIC and BNIA state this directly, and several independent retailer sources repeat the same rationale (cognac.fr; armagnac.fr).
- Keep it cool, dark and stable. Aim for somewhere in the region of 15–20°C, out of direct sunlight, and away from temperature swings. A kitchen cupboard near an oven or a sunny windowsill are both worse choices than a cool pantry or cellar-like spot (Martell; Grape and Barrel).
- Reseal properly after every pour. A snug cork or cap matters more than almost anything else here, since it's the main thing controlling how much air gets in between drinks.
- Once a bottle is well below half full, consider decanting down. Transferring the remaining spirit into a smaller, full bottle reduces the amount of headspace (and therefore air) in contact with the liquid, which is a legitimate and widely repeated way to slow further evaporation and oxidation (Martell; Grape and Barrel).
None of this is about food safety. It's entirely about keeping the flavour as close as possible to how it tasted the day you opened it.
A myth worth killing
You may see claims online that an old or expired bottle of brandy "can contain bacteria and other contaminants." At ~40% ABV, this isn't supported by anything in the sourcing for this article. It reads like generic food-expiry language applied somewhere it doesn't belong. The real risk with an old opened bottle is that it tastes flatter and less interesting than it used to, not that it's unsafe to drink.
The takeaway
If you've got an unopened bottle of cognac, armagnac or calvados tucked away, there's no rush. Store it upright, out of the light, and it'll be fine for years, cork condition permitting. Once it's open, there's still no need to panic: just stand it up, keep it cool and dark, seal it properly, and try to work through it within a year or two while it's showing its best.
Related reading
Sources
- cognac.fr — BNIC official FAQ
- Martell — how long can cognac be stored (FR)
- armagnac.fr — BNIA official FAQ
- armagnac.fr — distillation and ageing
- Wine Spectator — How long will an open bottle of Cognac last?
- VinePair — How to Tell If Your Spirits and Liqueurs Are Expired
- The Gray Report — Booze will NOT last indefinitely in an open bottle
- Whisky and Wisdom — Oxidation, does whisky go off in the bottle?
- Grape and Barrel — How to Store Cognac for Optimal Flavor
- Galactic — alcohol as a preservative
- cyalcohol.com — does alcohol preserve food
