What are table olives?

Table olives are the fruits of the olive tree ( Olea europaea ) that have been prepared so that they can be eaten raw. On the tree, olives are usually too bitter to eat raw, mainly because of oleuropein — a natural bittering substance that is not "unhealthy" but does have an intensely bitter taste. ^[1]

Green, purple or black: what does the color say?

Green and purple (black) olives don't come from different trees. They're the same olives in different stages of ripening. Green indicates a young olive, and the riper the olive, the more purple it becomes. The basic rule is: an olive starts green (-August) → purple patches (Sept/Oct) → purple (Nov/Dec). → almost black (Dec/Jan). Black olives are therefore the same olive as the green variety, only harvested later.

Black olives in the supermarket

Many black olives in the supermarket are originally green olives that have been artificially blackened through an industrial process. This process is faster, and naturally ripened black olives are soft and fragile, making them more difficult to process and pit mechanically. Naturally ripened black olives also have a different, deeper, sweeter flavor, are irregularly colored, and wrinkled. Consumers prefer all olives to be the same color and have a firm, black olive. Therefore, the green, firm olives are blackened through oxidation and color fixation with iron gluconate (E579) or iron lactate (E585).

Note: Color alone doesn't tell the whole story — processing method and salt/fermentation ultimately determine the flavor profile.

Invaiatura: the ideal transition moment

Invaiatura (also called veraison in Dutch) is the Italian term for the stage in the ripening of olives (and grapes) when they change color. This process is particularly crucial in viticulture and the olive harvest. Invaiatura is the stage at which an olive begins to change color from green to purple : the start of ripening. This is a popular harvest time for olives because it often achieves a nice balance of bite, aroma, oil content, and bitterness .

Debittering & Preserving: Brine/Fermentation vs. Fast Methods

1) Traditional: directly in brine (salamoia) and (often) fermentation

Many quality olives are placed directly in brine . This is often followed by a natural fermentation process in which lactic acid bacteria play a role. This process takes time (weeks to months), but often preserves the "olive character" and can produce more complex flavors. ^[2][3]

2) Faster: Industrial. First debitter with drain cleaner (NaOH), then brine.

A common rapid method (e.g., "Spanish-style") uses a short treatment with an alkaline solution (drain cleaner) to break down oleuropein more quickly. The olives are then brined/fermented. This is efficient and scalable, but often produces a different flavor and texture profile than slow-curing methods. ^[2][3][4]

Disadvantage of industrial treatment

• Breakdown of vitamins: Intensive processing and heating can also reduce levels of vitamin E and other healthy plant substances (such as tocopherols) by as much as 68% to 80%.
• Less complex fermentation: Natural olives undergo a slow ripening or fermentation process lasting months, which is beneficial for the formation of compounds that are good for gut flora. This is largely absent in the "fast" black olive.
• Increase in iron: There is one substance that actually increases: the iron content. This is due to the addition of iron gluconate (E579) to fix the black color, making these olives technically richer in iron than green olives.

Conclusion: If you're eating olives for the health benefits of antioxidants and polyphenols, it's better to choose naturally ripened olives, which are often brownish/purple in color. Naturally ripened olives are more likely to have a pit because this keeps the olive firm.

Taste & Texture: How Do You Taste Quality?

Tip: Let the olives sit at room temperature for 10–15 minutes before serving; this will help release their aroma better.

Tip: If you find olives in salt water too salty straight from the jar, rinse them first or let them soak in water for a few minutes.

Nutrition & Health: What Can (and Can't) Say?

Olives are a great addition to a Mediterranean diet —especially when used as an alternative to less healthy snacks. They provide primarily fat (often high in monounsaturated fatty acids) and contain bioactive compounds like polyphenols. The exact composition depends on the variety and processing. ^[2][5]

What does research say specifically about table olives?

Reviews describe that potential benefits are mainly related to fatty acid profile, vitamin E and polyphenols (including hydroxytyrosol compounds), but also emphasize that processing influences composition. ^[5]

And studies on one olive variety, such as Nocellara?

For example, there is a small pilot study on Nocellara del Belice table olives that examined biomarkers around oxidative stress/inflammation and body composition. Such studies are interesting, but remain small and do not provide evidence for concrete claims such as "weight loss from olives". ^[7][8]

Storage & serving