Where should you keep olive oil in the kitchen?

The quality of olive oil is not settled only on the day it goes into the bottle; where it stands in the kitchen decides its taste directly. Heat, light and air are the three shared enemies of this oil, and all three gather at the same spot in most kitchens.

Why is beside the stove the worst place?

The place an olive oil bottle stands most often is right beside the stove, because it is handy there. But the stove is the hottest point in the kitchen, and the temperature around the bottle rises with every round of cooking.

Heat speeds up the deterioration of the oil, and because that change moves slowly it is not noticed. The difference between the taste of the same bottle on the first day and its taste a few months later is usually put down not to the oil but to the palate getting used to it.

The answer does not have to be moving the bottle away entirely. A bottle standing an arm's length from the stove, behind a cupboard door, both stays handy and is protected from direct heat.

What does light change?

Light, together with heat, is the second factor speeding up the deterioration of the oil. This is why good olive oils are usually sold in dark glass bottles; the color of the bottle is not a design choice but a method of protection.

When a clear bottle is bought, that protection is lost. Keeping such a bottle in a closed cupboard, or transferring its contents into a dark bottle, wins back the protection that was lost.

A windowsill is one of the least suitable places for that reason. Pleasant as it may look, a bottle in direct sunlight changes far faster than a bottle inside a cupboard in the same kitchen.

What part does contact with air play?

Air gets in every time the cap of the bottle is opened, and that contact builds up over time. In a bottle that is half empty the air space left above the oil is large, and that speeds up the deterioration.

This is why buying a very large bottle is not always an advantage. A tin or a large bottle that will take a long time to finish keeps better if it is decanted into a small bottle for use; contact with air drops and the freshness is kept.

Closing the cap tightly is a simple but effective habit too. A cap half closed in a hurry gives the same result as a bottle left open all day.

Is the fridge an answer?

Olive oil turns cloudy and partly solid in the fridge; that is not spoilage and it returns to its former state at room temperature. But it is not a practical method for daily use.

The fridge can only be considered for an oil that will be stored a very long time and used rarely. For the bottle used daily, the right place is a cool, dark kitchen cupboard.

A cool pantry, or a cupboard in the kitchen away from the stove, already provides good enough conditions for most homes. Simply changing the bottle's place makes a clear difference, with no further arrangement needed.

How do you tell it has gone off?

The most reliable sign is the smell. The smell of olive oil that has lost its freshness loses its sharpness and takes on a heaviness like paint or old nuts.

The taste changes in the same direction. The slight sharpness a new olive oil leaves at the back of the throat disappears over time; a flat, undefined taste comes in its place and the character it adds to dishes drops.

Oil that has gone off has to be thrown out; it is not rescued by heating it or mixing it into another dish. The only way to prevent that is to set the amount you buy by how fast you get through it.

How many bottles should there be in a kitchen?

A practical arrangement is to use two bottles: a small one kept within reach for daily cooking, and the main source standing in a cool cupboard.

The small bottle is refilled from the main one as it empties. That way the main bottle is rarely opened, contact with air is kept to a minimum and the oil within reach is always fresh.

That arrangement makes the measure easier as well. The amount of oil poured from a small bottle is more visible; a large bottle is both heavy and lets out more oil than expected in a single movement.