Like wine, no two olive oils are exactly alike. There are at least 60 different kinds of olives, and each oil is different because of the soil, climate, olive type, and processing method. And like wine, olive oil is a changing, “living food. “.
There are many types of olive trees, but the domesticated Olea Europaea is the most common. It is a hardy evergreen tree with silver-green leaves that does best in dry, arid climates and mild winters. Olive trees can often be hundreds of years old and still bear fruit. They start producing fruit that can be used after five to eight years.
About 800 million olive trees grow around the world, in places like Australia and California. However, the 20 or so countries that make up the International Olive Oil Council produce 98 percent of the world’s olive oil. The IOOC operates under a United Nations treaty and sets standards of quality for member countries. Spain is the largest producer of olive oil in the world, followed closely by Italy. Greece is the third-largest producer, though it uses more olive oil per capita than any other country.
Worldwide, about 10 million metric tons of olives are produced each year. Nine million metric tons, or 93% of the crop, are pressed to make olive oil. One million metric tons are used for table olives. Only 15 to 20 kilograms (33 to 44 pounds) of olives will come from an old olive tree every year. One tree can only make three to four liters of oil a year, since it takes about five kilograms of olives to make one liter of oil. This is a very small amount of oil to make.
The olive is a drupe, a fruit like the peach and the plum, with a single hard stone. An olive branch will bear 10 to 40 clusters of the fruit. The olive’s flesh gets bigger as it ripens. Six to eight months after the tree’s flowers first show up, the olives are fully ripe and have the most oil.
When the olives are ready, pickers stand on ladders propped up on the branches and pick each one by hand, putting them in net bags as they go. Hand picking assures that each olive is not damaged, and that only the fully ripe olives are picked. Even though olives are picked by machines, these machines can’t tell the difference between ripe and unripe olives.
Right away, the olives are taken to an olive oil mill, where they are pressed for oil either that same day or the next, before they start to oxidize and ferment. The fruit of the tree, the freshly picked olives, are far too bitter and sour to eat. This is one of nature’s great ironies. Before the fruit can be eaten, it needs to be washed, soaked, brined or salted, and left to age. Virgin olive oil, on the other hand, comes from freshly picked bitter olives and is extracted without using heat, chemicals, or solvents. It should have a lush, rich flavor and a velvety texture, and it is ready to use right away.
“Cold-pressed” olive oil comes from olives that have been crushed with a traditional millstone or a stainless steel grindstone. No heat or chemicals are added during the process, which produces a heavy olive paste. The paste is then spread over thick, round straw or plastic mats that are placed in a press. This press extracts the liquid from the paste—a combination of oil and water. Either decanting or centrifuging are used to separate the oil from the water. The oil is then filtered to get rid of any big particles.
The resulting oil is then graded and classified, according to standards established by the IOOC. The finest oil has the lowest acidity, which is measured as a percentage per 100 grams of oil.
Extra Virgin: An olive oil can be called extra virgin if it has certain tastes and a total acidity of 1% or less. This means that it has perfect smells and tastes. Because of its purity, distinct taste, and limited production, extra virgin olive oil is the most expensive.
Virgin: The next grade down, virgin olive oil is produced without heat or additives, just like extra virgin. Virgin olive oil smells and tastes great, but it may have up to 2 percent more acidity than extra virgin olive oil. “Ordinary virgin olive oil,” rarely available in this country, may have up to 3. 3 percent acidity.
Olive Oil: The most popular type of olive oil is now just called “olive oil.” This is the new name for what used to be called “pure olive oil” or “100% pure olive oil.” Extra virgin olive oil costs more than a quarter as much as this oil, which has less than a 1. 5 percent and is a blend of refined olive oil and virgin olive oil. If the producer wants a certain flavor, the amount of virgin oil in a blended oil can be anywhere from 5 to 25 percent. This group includes the new “lite” olive oils, which taste and feel lighter than virgin olive oils but have the same amount of calories and fat.
Oil from Olive Pomace: This oil comes from pomace, which is the pulpy olive waste that comes after virgin olive oil has been taken out. Solvents are used to extract the oil, which is similar to how seed oils are made. The oil is then mixed with virgin olive oil. Pomace is usually the least expensive olive-derived oil product but may not be sold as olive oil. Production is limited and continues to decline because of advances in olive pressing technology.
Storing olive oil As long as it is properly cared for, olive oil has a long shelf life. Because it has antioxidants, it will stay fresh longer than other oils. In a restaurant, it will be eaten before the flavor goes away. Under proper conditions, olive oil may last up to 12 months (18 months if stored in metal containers). To keep olive oil fresh, buy it in tins or dark glass bottles. Light, heat, and air can damage it. The best place to store well-sealed containers is in a cool, dark place.
Oive oil can also be refrigerated, though it will become hazy. When the kitchen is hot, it’s best to keep big amounts in the fridge and pour out small amounts that will be used up quickly.
Occasionally, extra virgin oil will have particles floating in it. Not to worry. This is unfiltered olive oil, considered prime oil in the producing countries. The tiny bits of pressed olives that have been left in the oil add flavor and color.
How to choose an oil Personal taste, cost effectiveness and availability are important issues when choosing olive oils. But what appeals to you may not necessarily be the choice of a colleague. Nature, fortunately, has provided a wide range of styles and flavors.
It would be simple if you could group olive oil grades by how they taste, but that’s not possible. Some extra virgin oils are very rich but not too strong, others are fruity and light, and still others smell and taste like pepper and are almost too strong. Like the wines that small wineries make, the extra virgin olive oils that they make may taste different from year to year. The olive oil from large producers, particularly those who do a lot of exporting, tends to be consistent.
Professional chefs who know a lot about olive oil say they can tell the country of origin of an oil even when they are not tasting it. What they probably know most of the time, though, is a style that comes from a certain country.
The olive oil doesn’t have to be from a certain country to be bottled and labeled in that country. However, the oil and its grade must meet IOOC standards. The oil itself can come from different parts of the same country or from one or more other countries, but each producer will usually try to make the oil taste like it does in their own country. ”.
Some chefs choose which olive oils to use with which dishes in order to get the most authentic taste. For example, Spanish oil is used for paella, Greek oil for mezze, and French oil from Provence for tapenade. Restaurants usually have a few different kinds of olive oil on hand. An extra virgin olive oil is used for some cold dishes and room service. A virgin olive oil is used for sautéing, braising, roasting, and grilling. A pomace olive oil is used for frying.
There is a substance called an antioxidant that makes fats and oils last longer by slowing down the rate at which they go bad. Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are examples of manufactured anti-oxidants allowed by the U. S. Food and Drug Administration for use in foods.
The point at which an oil will catch fire but not keep going (650oF for olive oil) is called its flash point.
Foaming: The development and persistence of froth on the surface of fats or oils during frying. Foaming can indicate fat breakdown, but may also result from the presence of foreign material.
Hydrogenated: The addition of hydrogen to the molecule of an unsaturated oil or fat to make it solid. polyunsaturated: A fatty acid with two free carbon links. Most of the polyunsaturated fats in food come from oils from plants and fish, but coconut oil is an exception.
Pro-oxident: A substance that speeds up the reaction of fats with oxygen. Copper and iron are pro-oxidants. saturated: A fatty acid with no free carbon links. Unsaturated fats have a greater potential to develop rancidity. There is a fatty acid that changes from a liquid to a solid when hydrogen is added to an unsaturated oil.
At what temperature does oil start to smoke when heated at a certain rate? This is called the smoke point. A high smoke point is good for frying fat and shows that it has been refined well, but the amount of time that you have to fry something before it starts to smoke is a better indicator of how stable it is. A good cooking oil will have a smoke point between 420oF and 450oF. Olive oil has a smoke point of 437oF.
Olive oil is a kitchen staple renowned for its flavor and health benefits, But have you ever wondered just how many olive trees it takes to produce this delicious “liquid gold”? The number can vary based on several key factors
Olive Tree Productivity
-
On average, a mature olive tree yields 15-25 kg (33-55 lbs) of olives per year. Some may produce up to 50 kg (110 lbs).
-
It takes around 5 kg (11 lbs) of olives to make 1 liter of oil.
-
So each tree typically yields 3-5 liters (0.8-1.3 gallons) of olive oil annually
-
Yields depend on climate, variety, farming methods, tree age and health.
-
Well-cared for trees in ideal growing conditions produce more olives and oil.
Estimating Tree Numbers for Home Production
-
For personal use, 5-10 trees typically provide enough oil for most households.
-
Start with 10 trees to account for differences in yield. You can use extra for cooking, gifts, etc.
-
Trees start producing after 5-8 years, reaching peak yield around 15-20 years old.
-
Home harvests must be processed offsite at commercial mills. Coordinate timing with neighbors.
-
Weigh olives before pressing to estimate yield. Average oil content is 16-18% for small batches.
-
Pruning helps maximize yields by encouraging new fruitful shoots.
Olive Trees Needed for Commercial Production
-
Large operations need hundreds or thousands of trees for substantial production.
-
1 acre contains 100-150 trees. 1 hectare (2.5 acres) has at least 200-300 trees.
-
500 trees produce ~2,000 liters (528 gallons). 1,000 trees yield ~3,000 liters (793 gallons).
-
10,000 trees can yield 30,000 liters (7,925 gallons). Larger farms may have 100,000+ trees.
-
More trees = more potential oil, but focus is often on quality over quantity.
Key Factors Influencing Oil Yields
-
Olive variety – some cultivars naturally produce more oil.
-
Tree age – yields peak around 15-20 years old.
-
Climate – warmth and sunlight improve fruiting.
-
Soil – poor soils limit tree health and productivity.
-
Farming methods – impacts tree vigor and olive quality.
-
Pruning – encourages new fruitful wood.
-
Pest/disease control – prevents infection/damage.
-
Harvest timing – pick at peak oil content.
-
Processing technique – maximizes oil extraction.
Meeting olive tree needs results in higher yields. But emphasis on quality should take priority over quantity.
Producing Top Quality Olive Oil
-
Start with healthy trees suited for your climate. Prioritize cultivars known for quality oil.
-
Monitor groves for pests, disease, water needs, etc. Address issues promptly.
-
Allow olives to fully ripen on tree. Test sample for ideal harvest timing.
-
Pick by hand to minimize bruising. Use nets, not bags. Move gently.
-
Transport olives to mill immediately after harvest. Press within 24 hours.
-
Ensure equipment is clean to prevent contamination during milling.
-
After oil separation, allow to settle before filtration and bottling.
Careful production and processing preserves oil quality and flavor.
Estimating Your Needs
-
Consider how much olive oil your household uses per year.
-
Research yields in your area. Consult with local olive growers.
-
Allow time for trees to reach maturity and full production.
-
Start small with a few trees. Expand later once you have experience.
-
Weigh your harvests and pressed oil amounts. Track data to estimate future needs.
With some calculations and planning, you can determine how many olive trees you need to produce oil for personal use. While commercial operations utilize hundreds or thousands of trees, just 5-10 trees can potentially supply enough oil for home cooks. Pay close attention to quality, and your homemade olive oil will be atrue kitchen treasure.
Thanks for signing up!
Reality Check: Starbucks Workers United has organized the home offices store. And now it looks as if an actual strike may be coming.
The Bottom Line: KFC is joining Taco Bell and McDonald’s in creating a new brand. But such moves are risky, especially when the primary brand is struggling.
After years of making fancy menus and working weekends past midnight, skilled chefs are now finding more flexible and satisfying ways to be creative.
Want breaking news at your fingertips?
Get today’s need-to-know restaurant industry intelligence. Sign up to receive texts from Restaurant Business on news and insights that matter to your brand.
The latest from Restaurant Business, sent straight to your inbox.
How I Produce Olive Oil Using My Own Olive Trees
FAQ
How much olive oil can you make from one tree?
How many olive trees does it take to make a gallon of oil?
Are there enough olive trees to produce olive oil?