Black olives, the ripened fruit of the olive tree, are widely consumed but frequently raise questions about their sodium content. Canned or jarred black olives commonly found in grocery stores are generally high in sodium compared to most other whole plant foods. This elevated salt level is not inherent to the fresh fruit but results entirely from the preservation process required to make them edible.
The Sodium Reality
Canned black olives contain a substantial amount of sodium relative to a small serving size. A typical one-ounce serving (about five large or ten small olives) contains approximately 204 milligrams of sodium. This single serving contributes around 14% of the recommended daily value for sodium.
For a larger 100-gram portion, the sodium content often ranges between 735 and 875 milligrams. This amount represents roughly one-third of the total daily sodium limit recommended by the U.S. Food and Drug Administration (FDA) for adults (less than 2,300 milligrams per day). Since the FDA defines a food as high in sodium if a serving contains 20% or more of the Daily Value, a larger portion of black olives easily meets this definition.
The Role of Processing
High sodium levels in black olives are directly linked to the commercial curing process, which removes the fruit’s natural bitterness. Raw olives contain oleuropein, a compound that makes the fruit inedible directly from the tree. The most common method for producing uniform, canned black olives involves a rapid chemical treatment.
This process, often called the “California method,” uses an alkaline solution, typically sodium hydroxide or lye, to quickly neutralize the oleuropein. The lye treatment cures and softens the olives in days, accelerating the process compared to traditional methods that take months. After the lye cure, the olives are exposed to air, which oxidizes the fruit and creates the characteristic uniform black color.
The final step for sodium introduction is the preservation stage, where the olives are packed in a salt brine solution. This brine, which can contain 8% to 11% sodium chloride, acts as a preservative to prevent spoilage and adds the salty flavor consumers expect. The sodium is therefore an added ingredient for preservation and flavor, not a natural component of the fresh fruit.
Managing Sodium Intake
Consumers who enjoy black olives but need to reduce their sodium intake have several effective mitigation strategies. Rinsing canned or jarred olives with water is a simple technique that removes a significant amount of surface salt. Studies on similar brined foods, such as canned vegetables, indicate that draining and rinsing can reduce sodium content by anywhere from 9% to over 20%.
For those seeking inherently lower-sodium options, looking for specialized packaging is helpful. Some manufacturers offer “low sodium” or “no salt added” varieties, which bypass the heavy brining stage or use a less concentrated solution.
Another alternative is to try oil-cured black olives, which are first dry-cured in salt to draw out moisture and bitterness, then packed in oil. While oil-cured olives still contain salt, some varieties may have a lower sodium concentration per serving than heavily brined types, though labels must be checked carefully.
A further method for reducing the saltiness of any cured olive is to soak them in fresh water for a few hours, changing the water multiple times. This allows the salt to diffuse out of the fruit via osmosis. This longer soaking process can remove up to 60% of the saltiness, though it may also slightly alter the texture and flavor.