Trying to describe extra virgin olive oil seems at first to be quite easy. It is commonly stocked in every household, and in the UK it can even be found in the medicine cabinet. After some deliberation and a little more recent knowledge on the subject the perfect analogy for extra virgin olive oil has to be champagne.

Ask someone for their views on champagne and they can pontificate endlessly with strong opinions sometimes based on a single taste of the stuff. Love it, hate it, gives them hiccups, too expensive, and prefer cava anyway, without any comprehension of just how many different types are available. Cheap, expensive, big bubbles, little bubbles, even no bubbles – yes, a still champagne, extra dry to almost sweet, rosé … the list is endless and enough variations to suit every palate.

It’s the same with olives with hundreds of varieties to choose from, which I am sure you think about when choosing olives to eat but not when picking oil.
The UK remains a place of extremes ranging from some restaurant chefs not only cooking with but smothering just about everything in copious amounts of non specific olive oil, to popular branded restaurants where none is available, preferring sachets of vinaigrette instead.

In Spain even the lowliest restaurant, café or bar have readily available a choice of really good olive oil and vinegar for customers, and know what it should go on and how much of it is wanted. So perhaps we could all do with a little education.

For those holidaymakers who manage to prize themselves away from the beaches in Spain, venturing out and about will show them just how big the country is and the most beautiful and productive areas.

In Canena near Jaen, which we have visited, there are quite a lot of olive trees. Quantifying “a lot” is difficult in current times with words such as mega, humungous, and gazillions in daily use. A lot in this case is like saying the Grand Canyon is just a ditch albeit a big one.

Unless you have witnessed the amount of olive trees in this area alone or indeed the Grand Canyon first hand, it is impossible to describe either as anything other than staggering.

In our garden at home we have carob trees and some orange and lemon trees, plus a single olive tree which is apparently well over 150 years old. At first we were not really bothered about it bearing fruit as it just looks impressive, but a visit from a member of the local co-operative changed that.

He said the tree was indeed beautiful to look at but it was a bit old and tired and would probably not produce much fruit. However perhaps with a little love and attention, it might produce some.

One year after careful pruning, this massive tree bore four olives even though they fell within weeks. This year there are hundreds, which are not quite hanging like grapes but a considerable amount. Unfortunately once again we are beginning to lose the fruit due to a variety of reasons. If it’s too humid the leaves fall off, if the tree gets too much rain the flavour of the fruit is affected, not enough water and the fruit won’t form and that’s before you consider pests such as olive mosquitoes and the need for fertilisers. Time to find an expert ….

So off to Canena in Andalusia, a village dominated by the Vano family castle and the largest single estate in the region covering some 1,500 hectares, which has approximately 287,000 trees – and take our word that’s a lot of trees. Trees more than 100 years old are spaced at 100 trees per hectare and can produce approximately 100kg of fruit per season.

Younger trees, coupled with smaller and more efficient methods of cultivation and care, although producing less fruit per tree, yield some 70kg per season and are planted 204 trees per hectare.

Early harvest fruit is produced from specially selected areas of trees that are carefully nurtured until the harvest is ready late October or early November. Later picking in December yields more oil, some 23%, but obviously it is less concentrated than the early harvest and yields as little as 8%.

Knowing which trees are at the correct stage of ripeness when the fruit is neither all black or all green in the middle of 287,000 trees must be one hell of a job. Using simple maths from this estate alone, taking the number of trees times the amount of fruit collected divided by the yield, means that someone must be using huge amounts of oil.

It was an impressive start arranging to meet for a private lunch some 350 miles from home at the Canena Castillo where valued customers and visitors from around the world are entertained. With only my wife Trudy and me as guests this day we had the undivided attention of family members and the sales and promotion team for the estate. After lunch we were given a tour of the castle and then shown one of the mills that was gearing up for the start of the more major part of the season. Any hiccups with the machinery once the harvest starts could prove costly, so everything is checked thoroughly.

Next day was an early start to the groves and more specifically to the area designated for early harvest. The team, with the help of a mechanical trunk shaker plus three men with 3m long poles, can strip a heavily laden olive tree in less than two minutes. The olives fall on to clean sheets under the tree before being expertly folded and transferred into bags for collection.

Any olives that fall on the ground are gathered later and processed separately.

Early harvest olives can be picked at a rate of 25,000kg per day but when it all kicks off the main harvest delivers 150,000kg per day, with the record still standing at 173,000kg in one day. However, despite the speed and volume of the harvest, the way the olives are carefully handled throughout the process is surprising and no wonder it’s referred to as fruit. Nothing is wasted; even the stones are sold on as fuel while the pulp or pomace is sold on for further processing.

Our first taste of the first early harvest juice straight from the mill was in a small noisy storeroom at the production plant. Samples of both Picual and Arbequina varieties were drawn into plain ordinary bottles, strikingly different and distinctively individual they had in common the aroma, texture and flavour of two different types of nectar.

Arbequina oil tastes fruity and of honeycomb, caramel, nougat and hazelnuts, while the Picual smelt strongly of newly mown grass and yet tasted of green tomatoes, basil, rosemary, mint and citrus peel with a hint of freshly ground black pepper to finish.

While in the UK we might feel pressured to buy extra virgin olive oil based upon its health qualities or just because it’s trendy and then slosh it on or in just about everything, the Spanish are particular about which variety of olive is used and would never use extra virgin unless the flavour was required in the dish.

Picual and Arbequina are the two most widely grown varieties at Castillo de Canena and it recommends using the early harvest Picual for use in seasoning fish, the Arbequina for vegetables and desserts, and either included in your morning glass of orange juice. New varieties under test, including organic varieties, will have to undergo food matching at a later date.

In the Mediterranean everyone feels comfortable with olive oil instead of butter but in the UK there seems some reluctance despite the warnings to change. Chefs constantly choose “either or” option in their cooking when half butter and half extra virgin olive oil when cooking is not only the perfect solution but an early introduction for the young and underdeveloped palates.

There are calls for the DO (Denominacion de Origen) mark of identity to be more prevalent so that customers can be assured of the oils origin. Some restaurant chefs are guilty of making one litre of excellent single estate extra virgin olive oil last for at least 10 litres of cooking – known in the drinks trade as passing off.

While the information we gleaned from the workforce was interesting and educational, using the little Spanish I know, the off road ride around the vast estate was not. Corporate presentations and company gobbledygook, when packaging, promotion and price seem to take precedence over the product, is not interesting. Strip these away and you are mostly left disappointed. We never ask the correct questions which deserve the pre prepared correct answers, we just ask what interests us.

We always hear about the good years but what about the bad years? The predictable answer is “every year is different”. Ask again and the answer is “each year brings its own set of challenges”. Finally, so have there been bad years? “Well yes there’s been a couple of absolute disasters but luckily these were some years ago.” Easy when you know how!

So take away the castle, the nice lunch, the tour through the olive trees with the spectacular views, the boys harvesting the fruit while you watch, the gentle processing and the special limited edition bottles and what have you got left?

Well any one of the above “extras” would be a promoters dream come true but take it all away and what you have left is surprisingly in our case certainly one of, if not the most, amazing olive oil ever tasted.

Early this year we are to be presented with four new small olive trees. Although not as beautiful as the one we already have, these promise to produce vast amounts of fruit courtesy of the local co-operative in exchange for some of our homemade bread and pickles and spicy chilli chocolate cake.

When we asked what we should do with the copious fruit promised when it’s ripe, we were told to bring it to the co-op where our fruit would be added to other people’s fruit and then we could share the oil produced so our house would have a little of everyone’s house.

Should I jeopardise this generous spirit by asking what variety they are?

• Edwin and Trudy Cheeseman run the Thieves Kitchen Consultancy in Javea in Spain