All About Olives
The branches on this family tree of celebrated treats are diverse.
By Corinne Garcia
With little to no cholesterol and a rich store of beneficial monounsaturated fat, low in calories and carbohydrates, and high levels of antioxidants, iron, fiber and vitamin E, this tree fruit—yes, the olive is a fruit—has a long history in healthy Mediterranean diets. Research shows that monounsaturated fats can “favor weight loss,” as opposed to diets high in saturated fats (Obesity Journal 5/14/07). Olives also have a phytonutrient called hydroxytyrosol, which studies have shown to have anti-inflammatory and cancer-fighting properties while supporting cardiovascular health (Planta Medica 08/2011, European Foods Safety Authority Journal 2011).
Most olive varieties share these overall nutritional characteristics, although some differ slightly due to ripeness or processing. The nutritional downside to olives? High levels of sodium that comes from the salt brining process, necessary to de-bitter and soften this otherwise bitter, hard fruit. Here are some of the members of this diverse family.
Black Ripe/California Olive
The one that kids put on their fingertips and wave around, the black ripe olive is the most popular in the US and has the mildest flavor. “About 90% or more California-grown olives go into that style,” explains Bill Kruger, olive expert and farm advisor emeritus at UC Cooperative Extension. Typically they are made from larger varieties picked green (unripe), such as the Manzanillo, Sevillano, Mission or Ascolano. According to specialty olive processor Maurice Penna, this style became popular in the early 1930s because its quick cure—multiple-day lye curing interspersed with water and oxidation to de-bitter the fruit—facilitated mass production. The deep black color is set when the olives are pressure-cooked in the can, where they sit in mild salt brine. This process is much quicker than, and results in half the sodium of, a traditional salt brine cure—a couple weeks as opposed to several months. Acrylamide, a substance that in high levels has been found to increase the risks of developing certain types of cancers (Cancer Epidemiology, Biomarkers & Prevention 10/10), has been detected in canned black pitted olives; its presence is suspected to be processing related.
Flavor: The mildest olive with a slight buttery flavor, black ripes tend to be a favorite of kids. “You could call it a beginner’s olive,” Kruger says.
Typically made from the popular Manzanillo table olives imported from Spain, these are picked green, before they are ripe enough to change color, and are typically taken for processing on the same day as picking to cut down on bruising of the fruit. Processing of Spanish-style olives involves a two-step method that involves a quick lye bath for a partial de-bittering followed by a salt brine fermentation of three months to continue the process. “The Manzanillo, originally a Spanish variety, is the number one table olive in California and probably the world,” explains Kruger. “It means something like ‘little apple’ and they have a good flesh to pit ratio and good texture.” He explains that Manzanillos are commonly used in black ripe processing as well, but the Spanish style is where they shine, bringing out more of this olive’s bitter flavor. These are the ones you’ll often find stored in mild brine and stuffed with a pimento, which is said to add a complimentary sweetness to the tart olive. They tend to have higher levels of antioxidant substances called polyphenols.
Flavor: “These have a little sharper flavor,” Kruger says, adding that it’s probably due to the partial lye process followed by fermentation. “They aren’t real bitter, but sharper than the black ripe.” Others describe it as tangy with hints of smoky and woody flavors.
Popular in Sicilian cuisine for the salty flavors they add to dishes, Sicilian-style green olives are cured naturally, without a lye de-bittering, in what Penna calls a spontaneous lactic acid fermentation using Sevillanos, Manzanillo, Lucques or Kalamata olive varieties. This process allows the naturally occurring sugars from the olive fruit to leach out into the salt brine and feed the lactic acid bacteria, creating a natural fermentation process. “It’s basically a pickling process,” explains Kruger. These olives are cured for up to a year in lactic acid and salt, and they are still somewhat crisp when ready.
“There’s less sugar in black olive than in the green olives,” Penna says explaining why they use the freshly picked unripe greens in this process. “When you’re done, you have a wonderful layer of bitterness that doesn’t all leach out.” The lactic acid fermentation means that Sicilian olives provide the benefits of fermented foods, which have been proven to improve digestive, cardiovascular and immune health.
Flavor: Penna describes these as having a robust flavor, and a salty, residual bitterness. “I like to crack it and toss with olive oil, herbs and spices, and the Italians like it to add bitterness in their cuisine.”
Called a Kalamon olive in its native land of Greece after its namesake tree, the Kalamata olive is named after that region. Over the years it has made its way into kitchens worldwide as part of increased interest in the Mediterranean diet, in which Kalamatas serve as a staple in the traditional Greek salad. These olives are harvested ripe as opposed to green, meaning that their color has already started changing to black when they’re picked. Although the texture tends to be softer, this olive variety can stand up well throughout the curing process—other ripe olives would turn to mush.
Cured in a similar fashion to the Sicilians, some Kalamatas are simply salt-brined while others are brined and fermented with lactic acid. After brining many processors let them sit out for up to two days to allow for oxidation of the skin, resulting in a purplish hue. They then go back into brine with red wine vinegar and a little olive oil. “Kalamatas tend to loose their bitterness quickly,” says Penna. “And the process ensures a consistent flavor.”
Flavor: “They have a nutty flavor, kind of salty, and a little bitter,” says Kruger. Penna describes them as having a “winey” flavor that comes from the wine vinegar added to the curing process.
Often found swimming on the bottom of a martini glass, these green olives are large in size and flavor. Named after the Sevilla region of Spain where they originated, they are often referred to as the Spanish Queen due to the size and their Spanish style of curing. Although they have meaty flesh, they also have a large pit that when removed makes them perfect for stuffing. Sevillanos are often the ones found in gourmet markets stuffed with complimentary flavors. “The Sevillanos have a lot of meat,” explains olive curing expert Don Landis. “Because of their size, they can be used to stuff with almonds, blue cheese and garlic, and flavored with wine vinegar.” Sevillanos are also often found stuffed with pimento, a type of sweet pepper.
Flavor: “Sevillanos have a distinct residual bitter flavor,” Penna says. “And when they’re stuffed, the olive acts as a sponge and picks up the flavor.” They have also been described as being lighter and fruitier than their cousin, the Manzanillo.
With an appearance akin to a plump, shriveled raisin, the dry-cured olive is far from raisin-sweet, and is often described as an acquired taste due to its salty bitterness. “This is mostly used with black olives,” Penna says. “When they’re black they have a higher oil content than green ones that adds to a richer flavor.” The drying process is a salt cure which also de-bitters and preserves the olive, taking anywhere from four to six weeks. After mashing it slightly to loosen the skin, “you put the olive in salt to dehydrate it,” Kruger explains. “They are mixed over time and the salt leaches out the juices and the olive begins to break down.” After curing, the rock salts are shaken out and the olives are tossed in oil. “You’re counting on the salt and drying process to act as a preservative,” Penna says. From here, the shriveled products can be served plain or further flavored with herbs. They are typically used for snacking or in stews and salads.
Flavor: The salt cure tends to concentrate the natural bitter flavors of the olive instead of de-bitter it. “You can chop it up and use it in cooking; it’s like adding salt to a dish,” Kruger adds.
Grown mostly in the region of Languedoc in southern France, where they are commonly known as “green diamonds,” this bright green olive is named after the Italian Provence of Lucca where it originated. These medium-sized, fleshy olives have a distinct shape, like a crescent with a pointed tip, making them almost impossible to de-pit. In France, they are typically lye-cured or fermented and then placed in storage brine with citric acid or simple water brine, Penna explains. And either way, they tend to lose their bitterness rapidly. This curing method also keeps the flesh intact and somewhat crisper than many other olive varieties. “These are the rave of the country right now,” Penna says. “They just have a wonderful flavor, and texture and a small pit.”
Flavor: “It’s a great eating olive,” says Penna. Lucques have been celebrated for their sweet, buttery and nutty flavors; this olive variety is often compared in taste to an avocado, with little or no bitterness.
A very large-fleshed, light green olive from the Marche region of Italy and widely grown throughout California, the Ascolano has a more delicate flavor than many other green olives. “This is a larger olive, big in size like the Sevillanos,” Landis says. “It’s commonly used as a table olive.” Ascolanos are typically brine-cured, which adds saltiness to the mild-mannered flavor. They do well in stews and cooked sauces, and also make delicious pastes and tapenades. Although flavorful, with a nice texture, Penna explains that the skin is so easily bruised that it can be difficult to work with. “The people who use these olives love this olive,” he says. “They bruise so easily, but they cure out and make a wonderful eating olive.”
Flavor: “They have a nutty, fruity flavor,” says Landis. They’ve also been described as sweet with a slight peppery finish.