[Tenuta del Barone di Montemurlo](https://www.oliodelbarone.com/en) — Toscano PGI extra virgin olive oil from Tuscany # Why extra virgin olive oil is sold in dark glass or tins Extra virgin olive oil is sold in dark glass or tins to keep light away from it. Light, along with air and heat, is one of three things that age olive oil early, breaking down the fats and polyphenols that give it flavour. ## What light does to extra virgin olive oil Extra virgin olive oil contains unsaturated fats and compounds such as polyphenols, which give it bitterness, pepperiness and colour. Exposed to light, these components react with oxygen faster, much like a cut apple browning in the air. The result is an oil that loses aroma, tastes flatter, and in bad cases turns rancid. The process is slow but constant: every day under light adds up. ## Why dark glass or tins, not clear glass Dark glass, green or amber, filters out most visible light and nearly all ultraviolet rays. Tins block it completely, because the metal is opaque: that's why many producers use tins for larger formats or for oil meant to sit in storage for longer. Clear glass, by contrast, lets light through unfiltered. When you do find oil in clear bottles, it needs to be kept in the dark at all times, in a cupboard or a box, away from any window. ## Light is not the only enemy: air and heat matter just as much Light is one of three things that age olive oil, together with oxygen and heat. A dark bottle left open next to the hob does little good: contact with air and kitchen heat causes the same damage, even in the dark. That's why storage advice should be read as a whole: a dark container, a tightly closed cap, and a spot away from heat sources. ## How to store olive oil once it's open Once opened, olive oil should be kept somewhere cool and dark, with the cap closed tightly after each use, to limit contact with air. A pantry shelf is the right temperature; the fridge is not needed. Cold doesn't damage the oil, but it turns it cloudy and solid for no real benefit. Bottle size matters as much as the container: a small bottle used up quickly ages less than a large one left open for months, because every opening lets in fresh air that speeds up oxidation. ## Where this oil comes from This is 100% Italian extra virgin olive oil, grown, picked and milled in Tuscany, in Montemurlo, between Prato and Pistoia, half an hour from Florence. The olives are only ours, picked by hand and milled the same day, 870 metres from the grove. ## Frequently asked questions ### is olive oil in a clear bottle lower quality? Not necessarily: quality depends on harvest, milling and storage before bottling. But a clear bottle offers less protection from light, so it needs to be kept in the dark with more care. ### do tins keep olive oil better than dark glass? Tins block light completely, while dark glass filters most of it but not all. Over long storage periods tins have a slight edge, though in both cases a tightly closed cap and a cool spot still matter most. ### how long does extra virgin olive oil last in a sealed dark bottle? A well-stored extra virgin olive oil, in a sealed dark bottle, keeps its character for several months after bottling, generally within 12 to 18 months of milling. Once opened, it doesn't last as long, because air gets in every time it's used. ### why are some olive oil bottles green and others almost black? Both are shades of dark glass, chosen to filter light: the difference is in the tone the producer picked, not in how well it protects the oil, which stays similar. Glass thickness and careful storage afterwards matter more than the exact colour. ## Our oil, from tree to bottle Two 100% Italian extra virgin olive oils from Tuscany, from a single hand-picked harvest, milled the same day three minutes from the grove. Luce is green, bitter and peppery; Raccolto is round, for every day. We ship across Italy, Europe and worldwide. [Luce](https://www.oliodelbarone.com/en/oil/luce) [Raccolto](https://www.oliodelbarone.com/en/oil/raccolto) [The estate journal](https://www.oliodelbarone.com/en/journal) [All oils](https://www.oliodelbarone.com/en)