- How long does tonic water last once opened? The precise answer depends to a large extent on storage conditions — keep opened tonic water refrigerated and tightly closed.
How long does tonic water last in the refrigerator once opened? Tonic water that has been continuously refrigerated will keep at best quality for about 2 to 4 days after opening.
Is opened tonic water safe to drink after the "expiration" date on the bottle? Yes, provided it is properly stored and the bottle is undamaged - commercially packaged tonic water will typically carry a " Best By," "Best if Used By," "Best Before", or "Best When Used By" date but this is not a safety date, it is the manufacturer's estimate of how long the tonic water will remain at peak quality.
How can you tell if opened tonic water is bad or spoiled? After opening, commercially manufactured tonic water will start to become flat and lose flavor; if the tonic water develops an off odor, flavor or appearance it should be discarded.
Discard all tonic water from cans or bottles that are leaking, rusting, bulging or severely dented.
Sources: For details about data sources used for food storage information, please click here