How to Store Olive Oil (So It Doesn’t Go Stale)
Olive oil is a fruit juice, and like any fresh thing it fades. Four enemies spoil it — light, heat, air and time — and all four are easy to beat.
Most people store olive oil in exactly the wrong place: in a clear bottle, next to the stove, for two years. Each of those is a mistake.
The four enemies
Light degrades oil fast, which is why good oil comes in dark glass or tin — keep it out of the sun. Heat ages it, so the cupboard beside a hot oven is the worst spot in the kitchen; store it somewhere cool. Air oxidises it, so keep the cap on tight and don’t decant into a wide-necked jug. Time simply runs out: oil is best within about 12–18 months of harvest and noticeably tired after two years.
You do not need to refrigerate olive oil — a cool dark cupboard is fine, and the fridge just makes it cloudy and solid (harmless, but a nuisance). And a fancy clear glass cruet on the counter looks lovely and quietly ruins your oil; keep the good bottle in the dark and refill a small one for daily use. A well-stored oil keeps its peppery polyphenols — the flavour and the goodness — far longer.