What Percent of Peanut Butter is Oil?

January 10, 2026 •

4 min read

With peanuts classified as oilseeds, it's no surprise they are rich in fat, which is the primary source of oil in peanut butter. Depending on the brand and type, the total fat content can be as high as 50-70% by weight, but what percent of peanut butter is oil specifically? This figure can be broken down to understand the exact amount of peanut oil present, which is released during the grinding process.

Quick Summary

The specific percentage of oil in peanut butter depends on whether it is natural or conventional, with natural versions containing peanut oil exclusively. Commercial brands may include other vegetable oils. The oil content significantly impacts the product's texture, stability, and nutritional profile.

Key Points

Natural vs. Conventional: The percentage of oil varies significantly between natural (unstabilized) and conventional (stabilized) peanut butter.
Source of Oil: In natural peanut butter, the oil is simply the natural fat from the peanuts, which are classified as oilseeds.
Causes of Separation: The visible oil layer in natural peanut butter is caused by the natural process of separation (syneresis), as the less dense oil rises to the top.
Role of Additives: Conventional brands add hydrogenated vegetable oils as stabilizers to prevent this oil separation and ensure a uniform texture.
Total Fat vs. Separated Oil: The total fat content of natural peanut butter is around 50%, but the percentage of oil that visibly separates is typically much lower, often less than 2% after initial storage.
Nutrient Impact: Added hydrogenated oils increase the saturated fat content, while natural peanut butter contains primarily unsaturated fats.

Understanding the Oil Content in Peanut Butter

The oil content of peanut butter is a critical factor influencing its texture, nutritional value, and shelf stability. While the terms "fat" and "oil" are often used interchangeably in this context, it's more accurate to consider the total fat content, as oil is simply the liquid fat that separates or is bound within the peanut matrix. The proportion varies significantly between natural and conventional products.

The Composition of Natural Peanut Butter

Natural peanut butter is typically made with just peanuts and salt. The oil content is a direct result of the peanuts themselves, which are classified as oilseeds due to their naturally high fat concentration. The fat content in peanuts can range, but it's generally around 49-50% by weight. When peanuts are ground into a paste, this fat is released, creating the spreadable consistency. Without added stabilizers, this natural oil is free to separate and rise to the top of the jar over time, a process called syneresis. A 2022 study showed that after four weeks of storage at room temperature, an unstabilized natural peanut butter sample had an oil separation percentage of nearly 2%.

Peanut Type Matters: The oil content can vary based on the peanut cultivar used.
No Added Oils: True natural peanut butter contains no added oils or other emulsifiers.
Requires Stirring: The separated oil in natural brands must be stirred back into the product before use.

The Role of Added Oils in Conventional Peanut Butter

Conventional peanut butter, such as that made by major commercial brands, contains additional ingredients beyond just peanuts and salt. The FDA mandates that for a product to be labeled "peanut butter," it must contain at least 90% peanuts by weight. The remaining percentage can consist of optional ingredients, including sweeteners, salt, and, crucially, stabilizers like hydrogenated vegetable oils.

Stabilizers Prevent Separation: These hydrogenated oils are added to prevent the natural oil separation that occurs in pure peanut butter. They create a more stable, homogenous, and creamy texture that does not require stirring.
Commonly Used Oils: Examples of oils used as stabilizers include fully hydrogenated cottonseed, rapeseed, and soybean oil. Since 2015, the FDA has largely eliminated the use of partially hydrogenated oils (which create trans fat) in peanut butter, leading to the use of fully hydrogenated alternatives.
Impact on Nutritional Profile: The addition of these oils increases the saturated fat content of the final product.

Comparing Natural vs. Conventional Peanut Butter


Feature	Natural Peanut Butter	Conventional Peanut Butter
Oil Source	Only natural peanut oil released from the ground peanuts.	Peanut oil, plus added hydrogenated vegetable oils.
Oil Separation	Significant and common; oil rises to the top over time.	Virtually none due to added stabilizers.
Texture	Can be firmer or more liquid, depending on mixing and temperature; requires stirring.	Consistent, smooth, and homogenous texture that does not require stirring.
Ingredient List	Minimal, often just "peanuts" and "salt".	Peanuts, sugar, salt, and hydrogenated oils.
Fat Type	High in monounsaturated and polyunsaturated fats; low in saturated fat.	Higher in saturated fat due to the hydrogenated oils.

The Significance of Fat Composition

Beyond just the total percentage of fat, the type of fat is also significant. Peanut oil is composed primarily of unsaturated fats, specifically monounsaturated and polyunsaturated fatty acids. This includes oleic acid (a monounsaturated fat) and linoleic acid (a polyunsaturated omega-6 fat). The high concentration of these unsaturated fats is a key reason for the oil's liquid state at room temperature, which contributes to the oil separation in natural varieties. The addition of hydrogenated oils in conventional peanut butter increases the saturated fat content, which is solid at room temperature and helps create the desired stable, creamy consistency.

Conclusion

So, what percent of peanut butter is oil? The answer is not a single number but depends entirely on the product type. For natural peanut butter, the oil content is derived solely from the peanuts themselves and is roughly 50% by weight, though a visible layer that separates is a smaller percentage. For conventional brands, the specific oil percentage is a blend of natural peanut oil and added hydrogenated vegetable oils, which are used as stabilizers and are typically a small percentage of the total weight. Ultimately, the oil in peanut butter is a fundamental component that defines its texture, stability, and nutritional profile, highlighting the key difference between natural and conventional products. A true understanding requires looking beyond a single percentage to the composition and processing behind the label. For a deeper dive into the science behind the ingredients, research from the National Institutes of Health offers extensive studies on the functionality of stabilizers in peanut butter, providing a highly authoritative resource.

Frequently Asked Questions

The oil layer on natural peanut butter is caused by syneresis, a natural process where the peanut's less dense oil separates from the solid particles and rises to the surface over time because no stabilizers are added to prevent it.

Natural peanut butter's oil content comes solely from ground peanuts, while conventional brands add extra hydrogenated vegetable oils (like soybean or cottonseed) as stabilizers to prevent separation and maintain a smooth texture.

No, the separated oil in natural peanut butter is not bad for you. It is the peanut's natural fat and is perfectly safe to consume.

To mix the oil back in, simply stir it thoroughly with a utensil. Some people find it easier to warm the jar slightly or store it upside down to make the process more efficient.

Hydrogenated oils are vegetable oils processed to be solid at room temperature. They are used in conventional peanut butter as stabilizers to prevent the natural oil separation and create a consistently creamy texture.

Yes, you can add a neutral-tasting oil, such as peanut or sunflower oil, to dry peanut butter to improve its consistency. Mix it in gradually until you achieve the desired spreadability.

Yes, storing natural peanut butter in the refrigerator can slow down the oil separation process. The cooler temperature thickens the oil, making it less likely to rise to the top.