Is Olive Oil Gluten-Free?

Plain olive oil is gluten-free, since it contains olives and nothing else. However, it's possible under certain circumstances for particular brands and varieties of olive oil (especially flavored varieties) to be cross-contaminated with gluten, so you do need to be careful when deciding which brand of olive oil to buy.

These six olive oil brands are recommended for those following the gluten-free diet:

• Bariani Extra-Virgin Olive Oil (produced in a gluten-free facility)
• Filipp Berio Olive Oil (labels products "gluten-free")
• Jovial Extra-Virgin Olive Oil (produced in an allergen-free facility)
• Mary Ruth Organics Ice-Pressed Raw Extra Virgin Olive Oil (labeled "gluten-free")
• Palermo Olive Oil (certified gluten-free)
• Pompeian Olive Oil (labeled "gluten-free")

Read on to learn the details of each brand, plus what you need to know about olive oil for when you're eating gluten-free.

How Olive Oil Is Made

Olive oil is produced by pressing olives so that the oil is squeezed out. It's so simple that it's actually easy (although not very efficient) to make olive oil at home: five pounds of fresh (not marinated) olives will produce less than two cups of olive oil. Olive presses have been in use across parts of Europe and the Middle East for many thousands of years.

Commercially, olive oil is extracted either through pressing (as you can do at home, but on a massive scale), by using a centrifuge, or through what's called "cold dipping" (alternatively known as "the Simolea method"). In some cases, heat is used to augment the process.

Pressing is considered one of the best ways to make olive oil. First, the olives (pits and all) are ground up into paste. Then, that paste is pressed between discs to extract the oil. Cold dipping, which involves blades that dip into the olive oil paste repeatedly to collect a light coating of oil that's then wiped off, also is considered superior.

When olive oil is labeled "cold-pressed," that means no heat was used; heat can cause the oil to become oxidized, which makes it less healthy and desirable.

Olive Oil Types and Uses

Olive oil comes in many different varieties or "grades," including one that's designated as only being suitable for burning in lamps. But the olive oil you'll find at the grocery store can be separated into four main types:

• Extra Virgin Olive Oil: This is considered to be the best olive oil. It's produced using only chemical extraction methods (e.g., pressing, centrifuge, or cold dipping), and it's almost always cold-pressed. Extra virgin olive oil will be darker green in color, will be more viscous than other oils, and will taste like olives. Use this olive oil over salads or in other recipes, but be careful cooking with it, as it will smoke heavily if it gets too hot.
• Virgin Olive Oil: This grade is considered to be one step below extra virgin olive oil. It's extracted only using mechanical methods, but heat sometimes is used. Virgin olive oil may be a lighter green in color when compared to extra virgin olive oil, and may seem a bit less viscous. You can use virgin olive oil for salads or for cooking. It's also less expensive than extra virgin olive oil.
• Pure Olive Oil: sometimes labeled simply "olive oil," this is a highly refined olive oil. It's greenish-yellow in color and is much less viscous than extra virgin olive oil, and it's neutral in taste. This is a good choice for cooking since it smokes less than extra virgin olive oil.
• Light Olive Oil: This is the most highly refined type of olive oil you'll encounter. It's light yellow in color (with a hint of green). This is the best choice of olive oil for high-heat cooking.

Most good cooks will have two different types of olive oil handy: one bottle of high-grade extra virgin olive oil (for use in salad dressings and other applications where flavor is key), and another bottle of pure olive oil or light olive oil (for use in high-heat applications such as frying and sauteeing).

When Olive Oil Contains Gluten

Since olive oil is made from olives, the only ways for gluten to enter the picture are through gluten cross-contamination in processing, or through added ingredients. 

It's possible for olive oil to be cross-contaminated in processing. The equipment used to produce olive oil is specialized, but, theoretically, it also could be used to make wheat germ oil. Alternatively, olive oil could be produced in a shared facility that also processes gluten-containing products.

It's also possible for flavored or infused olive oils to contain added ingredients that are derived from a gluten grain. In practice, the only gluten-related risk you'll encounter in olive oils is in smoke-flavored oils—barley is used as a component of natural smoke flavoring. Therefore, you should avoid all flavored olive oils that list "natural smoke flavoring" or "smoke flavoring" as an ingredient, unless you've double-checked with the manufacturer and determined that the smoke flavor does not contain barley.

It's theoretically possible for other spices and flavorings used in flavored or infused olive oils to contain gluten, even at very low levels. Therefore, if you're particularly sensitive to trace gluten, you should stick with only the recommended brands of plain olive oil (it's easy to add your own spices and flavorings).

Recommended Brands of Gluten-Free Olive Oil

The following manufacturers state that their olive oils are gluten-free:

• Bariani Extra Virgin Olive Oil: Bariani is a small California company that only produces cold-pressed extra virgin olive oil and balsamic vinegar in small batches. It's expensive, but has gained a following among some in the gluten-free community for its purity and taste.
• Filipp Berio Olive Oil: This company, which bills itself as "the first and last name in olive oil," makes seven different varieties, including: Robusto Extra Virgin, Extra Virgin, Delicato Extra Virgin, Organic Extra Virgin, 100% Italian Organic Extra Virgin, California Extra Virgin, Pure Olive Oil, and Extra Light. All are labeled "gluten-free."
• Jovial Organic Extra Virgin Olive Oil: This olive oil may suit you if you're allergic or sensitive to more than just gluten grains. According to the manufacturer, the olive oil is made in a dedicated facility free from: tree nuts, peanuts, soy, dairy, eggs, wheat, fish, shellfish, and corn.
• Mary Ruth Organics Ice-Pressed Raw Extra Virgin Olive Oil: Pressing olives at an even colder temperature than traditional cold-pressed olive oil allows the resulting oil to retain more taste and nutrients, according to the company. Mary Ruth Organics labels its olive oil "gluten-free."
• Palermo Olive Oil: These oils—available in extra virgin and pure varieties—are certified gluten-free by the Gluten-Free Certification Organization (GFCO), which requires companies to test products to ensure they contain less than 10 parts per million of gluten.
• Pompeian Olive Oil: You should be able to find Pompeian in your local supermarket. The manufacturer makes four different plain olive oils: Extra Virgin Robust, Extra Virgin Smooth, Classic Pure, and Extra Light Tasting. All are considered "naturally gluten-free," according to the company.

A Word From Verywell

In almost every case, olive oil is gluten-free. Just avoid smoke-flavored olive oils, which can contain barley. If you're particularly sensitive to trace gluten, stick with a gluten-free-labeled olive oil (so that you know manufacturers have taken the necessary precautions against gluten cross-contamination). 

Olive oil, which is heavily featured in the Mediterranean Diet, is a great addition to your own diet. Use it to make homemade gluten-free salad dressings and marinades, drizzle it on gluten-free crackers, or top vegetables with it before roasting them in the oven.