Pig fat is used for cooking, baking, soap making, biodiesel production, industrial lubrication, and even pharmaceutical ointments. It’s one of the most versatile animal fats, with applications stretching well beyond the kitchen. Once rendered into lard, pig fat becomes a stable, flavor-neutral cooking fat that also happens to be a valuable raw material for manufacturers across several industries.
Cooking and Frying
Lard’s high smoke point makes it one of the better fats for frying. It holds up well at high temperatures without breaking down or producing off-flavors, which is why it was the default frying fat in American and European kitchens for centuries before vegetable oils took over. You can use it anywhere you’d use cooking oil: sautéing vegetables, searing steaks, frying eggs, or deep-frying.
Nutritionally, lard is roughly 37% saturated fat, 46% monounsaturated fat, and 17% polyunsaturated fat. That means about 60% of its fat is unsaturated, a ratio that surprises people who assume it’s purely saturated. It also contains vitamin D, particularly from pigs raised with sun exposure. Research from a study published in PLOS One found that pork fat from sun-exposed pigs contained around 184 IU of vitamin D per 100 grams.
Baking: Why Lard Makes Flaky Pastry
Lard is prized in baking for a specific reason: it forms large, stable fat crystals. When you cut cold lard into flour for a pie crust, those crystals create distinct layers. As the crust bakes, the fat melts and leaves behind tiny air pockets, producing the crumbly, flaky texture that’s difficult to replicate with butter or shortening alone.
Not all pig fat works the same way in pastry, though. The two main types are fatback lard and leaf lard, and they come from different parts of the animal. Fatback is exactly what it sounds like: fat trimmed from the pig’s back after the main cuts are packaged. When rendered, it produces lard with a slight porky flavor, making it ideal for savory applications like pie crusts, roasted vegetables, and pan-frying.
Leaf lard comes from the fat surrounding the pig’s kidneys. Because it’s not embedded in muscle tissue, it renders into a much more neutral-tasting fat with no pork flavor at all. That makes it the preferred choice for sweet baked goods like dessert pie crusts, cookies, and quick breads. You can substitute it for coconut oil or butter in most recipes.
Soap Making
Pig fat has been used in soap production for centuries. The process involves mixing rendered lard with an alkali (traditionally lye) in a chemical reaction called saponification. Lard has a saponification value of 193, meaning it takes 193 milligrams of potassium hydroxide to convert one gram of fat into soap. This value tells soap makers exactly how much alkali to use for a complete reaction.
Lard-based soaps produce a hard, long-lasting bar with a creamy, mild lather. Many artisan soap makers still use lard as a primary fat because it’s inexpensive, widely available, and creates a bar that’s gentle on skin. Commercial soap manufacturers have largely switched to palm oil and tallow, but lard remains popular in small-batch production.
Biodiesel Fuel
Waste pig fat from slaughterhouses and food processing plants can be converted into biodiesel through a process called transesterification. The fat is first cleaned to remove non-fatty residues and water, then mixed with methanol and a chemical catalyst at controlled temperatures. Using a sulfuric acid catalyst at 60°C for two hours, researchers achieved a biodiesel yield of 65.7% from waste animal fat. A potassium hydroxide catalyst produced a lower yield of 48.8%, partly because the reaction generates excess water that interferes with the conversion.
The resulting biodiesel is washed multiple times to remove impurities, then dried. It can be blended with conventional diesel or used on its own. Converting waste fat into fuel addresses two problems at once: it diverts slaughterhouse waste from landfills and produces a renewable energy source from material that would otherwise be discarded.
Industrial Lubricants
Lard oil, refined from pig fat, has a long history as an industrial lubricant, particularly in metalworking. More recently, researchers have developed bio-lubricants from lard that meet the specifications of ISO VG 100 and 200 grade oils, which are standard classifications for gear oils used in automobiles and machinery. Testing has shown that lard-based lubricants suspended in ethanol and modified with bio-additives match the wear resistance of conventional petroleum-based lubricants, and in some cases outperform other bio-based alternatives.
For countries that import large volumes of petroleum-based lubricants, domestically produced lard-based alternatives could reduce costs while using a renewable resource. This application is still more common in research settings than on store shelves, but the performance data is promising enough that commercial development is underway.
Pharmaceutical and Medicinal Ointments
In traditional medicine across many cultures, pig fat was applied directly to the skin to treat bruises, inflammation, and minor injuries. Modern pharmaceutical research has validated some of this folk knowledge. Scientists have isolated a specific compound from lard with anti-inflammatory properties, and it has been formulated into topical ointments, creams, and gels for skin application. A patent filed for a pharmaceutical composition derived from pig fat describes its use in treating acute inflammatory conditions through topical application.
Lard also served as a base for medicinal salves before petroleum jelly and synthetic ointment bases became standard. Its smooth texture, skin compatibility, and ability to carry active ingredients into the skin made it a practical vehicle for delivering medicine topically. While modern pharmaceuticals have largely moved to synthetic bases, lard-based ointments persist in some traditional and compounding pharmacy practices.
Other Everyday Products
Beyond these major categories, pig fat shows up in products you might not expect. It’s used in some cosmetics and skin creams as an emollient. Historically, it served as a leather conditioner, keeping boots and saddles supple. Rendered pig fat was also used to make candles before paraffin wax became cheap and widely available. In some regions, it’s still used to season cast iron cookware, creating a durable nonstick surface through repeated heating and polymerization of the fat.
The sheer range of applications reflects pig fat’s chemical versatility. Its balance of saturated and unsaturated fatty acids gives it useful properties at room temperature (solid enough to hold structure) and at high heat (stable enough not to break down quickly), making it adaptable across cooking, manufacturing, and energy production.