Access to light, oxygen and heat will all make olive oil go rancid. This is why we use the bag-in-a-box method of packaging. The bag has a triple layer metalised lining that ensures the no light can access the olive oil. The same bags (just much much bigger) are used from the processing plant right through to your kitchen to ensure your olive oil never sees the light of day. The dark bottles you are used to seeing on supermarket shelves for olive oil will keep your oil fresher for longer than a clear bottle, but it wont keep it anywhere near as long as the two year minimum shelf life of olive oil in a metalised bag. The other problem with bottles is that every time you open the bottle you allow air in to mix with the oil. This causes oxidation and the oil will soon become rancid. We have decided to use a non-drip tap which lets olive oil out of the bag but doesn't let air in. This non-drip tap will also make for a much cleaner pantry. Two points to remember with the non-drip tap though. 1. Turn it OFF! Seems obvious but many people forget to turn it all the way off. Make sure you feel the small 'click' when turning it off. 2. It is non-drip because it pushes a plug down through the hole when you turn the tap to the off position. This action will push one last drop through the outlet which needs to be wiped up before putting back in the pantry. For this reason I like to call it a one-drip tap, however the marketers of it prefer us not to call it this!
So we've taken care of making sure light and oxygen doesn't get to your precious oil. It is now up to you to avoid the third cause of decreasing your olive oils shelf life. Heat. Whilst it is handy to keep olive oil next your stove top, make sure you give it some room from the heat. The cooler the better, but ideally it should be kept below 25 degrees Celsius. Pantry is the best spot. Some people have kept it in the fridge and this is fine, although it will go cloudy if stored this way. This is purely cosmetic and your oil will return to normal colour and consistency when back to room temperature.
Lastly... We always recommend to store the casks upside down (tap at the top). I have never heard of one of our taps leaking (we check each tap twice before being sold), but this doesn't guarantee a parent-in-law (how politically correct) wont accidentally forget to turn the tap off before putting back into the pantry.
Follow these tips and your olive oil will last well past the best-before date (not that I encourage this!)
Manager Seaview Grove